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	An elliptical table		2005-01-03
		From Roger: Want to make an elliptical table, say the long (major) axis is 4 feet, and the short (minor) axis is 3 feet. I can construct this figure, but I'm trying to figure out what the exact dimension of a rectangle within this ellipse will be if I make the table a drop leaf type where the drop dimensions are equal for each end of both the long and short axes. Intuitively, it looks like there is one and only one solution. Answered by Penny Nom.
	Standard deviation		2005-01-02
		From Urial: Find the standard deviation of the given data set To get the best deal for CD dealer, Jessica called eight appliance stores and asked the cast of a specific model. The prices she quoted are listed below. $300, $203, $272, $332, $440, $119, $129,$254 Answered by Penny Nom.
	A 4-digit access code		2005-01-02
		From Missi: I need to find the 4 digit number to access my voice mail. These numbers will be 0-9 & numbers can be repeated. Could you provide me with a list of possibly combinations? If not, do you know anywhere that I could get a list of combinations so I don't have to write it all down? Answered by Harley Weston.
	A line from the center of the patch to the periphery		2005-01-01
		From Sandrine: I am currently researching a patch disease of grasses. These patches are roughly circular. I need a term for a line from the center of the patch to the periphery. Since the patches are not perfectly circular, my supervisors tell me I cannot use the word 'radius'. What else could I use? Answered by Denis Hanson and Harley Weston.
	A geometry problem		2005-01-01
		From Alexandra: In triangle ABC, b=40, and angle A= 30 degres. What values of BC will give two solution for angle B? Answered by Penny Nom.
	The golden ratio		2004-12-31
		From Cristina: let x represent the longer segment. to find the golden ratio, write a proportion such that the longer of the two segments is the geometric mean between the shorter segment and the entire segment.Use the quadratic Formula to solve the proportion for X. Find the value in both radical and decimal form. Answered by Penny Nom.
	The area of a triangle		2004-12-30
		From Perry: What is the area of a triangle with dimensions 3"X5"X7"? Could you provide the formula? Answered by Penny Nom.
	Gallons in a cylinder		2004-12-29
		From Dean: I have 2 cylinders: Cylinder A = 8'D x 12'H Cylinder B = 10'D x 15'H Each 1ft represents how many gallons of fluid? Cylinder A=? Cylinder B=? Answered by Penny Nom.
	Cubic yards of dirt		2004-12-28
		From Stephen: How many cubic feet or yards of dirt would be required to cover a 5 acre tract of land to a depth of 10 feet of compacted dirt? Answered by Penny Nom.
	Six digit numbers with at least one 7		2004-12-27
		From Behzad: How many six-digit numbers contain at least one 7 in their decimal expansion? Answered by Penny Nom.
	2^9833 days from today		2004-12-26
		From Pauline: Today is Monday, 1 October 2001. What day of the week will be 29833 days from today? Answered by Penny Nom.
	Half of five		2004-12-26
		From Pauline: Why is four half of Five? Hint: It's the middle half? Answered by Penny Nom.
	Modelling monthly temperature with a cosine		2004-12-25
		From Regis: The average monthly temperature for a location in Ontario as a function of month number can be modelled using the equation y = a cos[k(t + b)] + d. Answered by Harley Weston.
	An arithmetic progression		2004-12-24
		From A student: the 4th and 5th term of an arithmetic progration 47 and 52 respactively find a)d b)a1 c)a50 Answered by Penny Nom.
	Irrigation and a sector of a circle		2004-12-23
		From Chuck: A friend of mine is a farmer and uses Pivots to irrigate portions of his land. The crop rows are in straight lines that all form chords of a large circle. The intent is to determine area between any two "boundary" rows expressed in acres. Answered by Harley Weston.
	252 x ? is a cube		2004-12-22
		From Andrea: What is the smallest positive interger by which 252 can be multipled so the result is a perfect cubed? Answered by Penny Nom.
	Making the number 99999		2004-12-22
		From Lisa: Make as many equations as possible to make the number 99999 using all of the numbers 0-9 but only once per equation. example 01234 + 98765 = 99999 she needs to make 150+ equations. Answered by Paul Betts.
	A Reuleaux triangle		2004-12-22
		From Bob: I am trying to remember the name given to the regular figure constructed from three arcs. The figure is like an equilateral triangle except with arcs for each side. Answered by Chri Fisher.
	Divisibility by 15		2004-12-19
		From Lisa: My son was asked to find divisiblity rules for 15. We have been unable to find the answer. Does it exist? Answered by Leeanne Boehm and Denis Hanson.
	The gradiant of a hill is 9%		2004-12-18
		From Jim: The gradiant of a hill is 9%. What angle is created by the run/rise of the hill and 0 degrees? Answered by Penny Nom.
	Two intersecting lines		2004-12-18
		From James: Imagine a vertical line 1.107' tall. Leaving the top of this line, sloping down to the right at a 4:1, at what horizontal distance will the line strike a second line, which leaves the the bottom of the vertical line sloping down to the right at a rate of .02 ft/ft (or 2%)? There is a fairly easy solution to this, but I have lost my notes! Answered by Harley Weston.
	A two equation fact family		2004-12-17
		From Tony and Hailey: My Daughter Hailey had this question as part of her 4th grade math homework. Name 2 fact families that have only two equations. For the life of me I can't figure it out. Any ideas? Answered by Penny Nom.
	0.999..., asymptotes and infinity		2004-12-17
		From Mike: My Name is Mike and I teach high school. I had a student ask me to explain why .9 repeating is equal to 1. Then he asked me about an asymptote, or why a parabola or any other curve for that matter can continually approach a value (like 1) and yet never attain a value of 1. He is thinking that these two should represent the same concept and yet they contradict each other. Do you have a solid explanation for him? Of by the way he is a 7th grader. Great little thinker!!!!! Answered by Claude Tardif and Harley Weston.
	2^10 = -1/2^x - 1		2004-12-13
		From Randy: Could you explain to me how the following equation is solved please. 2^10 = -1/2^x - 1 Answered by Harley Weston.
	ln(x)/x		2004-12-11
		From Tina: What is the derivative of (ln x)/x? The double derivative? Answered by Penny Nom.
	A geometric proof		2004-12-11
		From Hanna: Given: ABCD is a quadrilateral; Prove: ABCD is a parallelogram Answered by Penny Nom.
	A sequence		2004-12-11
		From Amanda: Find the nth term of the following sequence 4, 10, 28, 82 Answered by Penny Nom.
	Three calculus problems		2004-12-09
		From Ashley: Hi, I am having a lot of trouble with three calculus questions and was wondering if you could help Answered by Penny Nom.
	Strings of 4 digits from 1,2,...,7		2004-12-09
		From Tom: How many different combinations can be made of the numbers 1-7 in 4 string combinations in any order? EX:7-2-3-5, 3-5-1-7, etc... And if you were to include the same 2 numbers in every combination, how many would that make? EX: Using 1 & 2: 1-2-7-4, 5-1-4-2, 2-7-5-1, etc... Answered by Penny Nom.
	Combinations		2004-12-09
		From Keith: i have a bucket that can hold 12(or x) number of rocks. if i have 13(or y) rocks how many different combinations of rocks can i put in the bucket without having the exact same 12(or x) rocks in the bucket. is there a formula that can be used for this problem in all cases and if so how and why does it work. Answered by Penny Nom.
	A regular hexagon is inscribed in a circle.		2004-12-08
		From Abraham: A regular hexagon is inscribed in a circle. What is the ratio of the length of a side of the hexagon to the minor arc that it intercepts? (1) pi/6 (2) 3/6 (3) 3/pi (This is the correct answer.) (4) 6/pi I found the length of the minor arc to be (pi)(r)/3 by doing a sixth of the circumference(2pi r).But I can't find the length of the radius to finish off the problem. If I knew the radius I would then plug it into the above and then use the radius again to be the length of the side because the triangle(one of the six of a hexagon) is equilateral. But can you show me how to get the radius to be 3? Thank you so much. Answered by Walter Whiteley.
	A belt around two pulleys		2004-12-07
		From Ian: a belt is stretched around two pulleys whose centers are d units apart and whose radii are R and r respectively (obviously R+r<d). the challenge is to find the length of the belt, l as a formula in terms of R, r, and d only. Answered by Penny Nom.
	An arc of a circle		2004-12-05
		From Ruben: i have an arc 55 inches wide, 12 inches high at the centerline of the arc. how can i determine the diameter of the circle that would correspond to the arc. Answered by Penny Nom.
	Geometric sequence		2004-12-04
		From Lesa: Find a formula for the geometric sequence: (√3 - √2), (4 - √6), (6√3 - 2√2), … Answered by Penny Nom.
	Probability		2004-12-04
		From A parent: Consider a 30 sided polygon. If three diagonal are selected at random, what is the PROBABILITY that they share a common endpoint? Answered by Denis Hanson.
	"a" cubed minus "b" cubed		2004-12-02
		From Denise: "a"cubed minus "b"cubed equal (a-b) times ("a"squared plus "ab" plus "b"squared)? I know this is a formula, but why is it true? Answered by Penny.
	Select a card from the deck.		2004-12-02
		From Heidi: Select a card from the deck. What is the probability that this card will be red? Show the number of expected outcomes versus the number of total possible outcomes. What type of event does this represent? Answered by Penny.
	1/x + 1/y = 2/31		2004-12-01
		From matt: I have this problem which I think is a bit more tricky than usual. x and y are positive integers. 1/x + 1/y = 2/31 Answered by Claude Tardif.
	e = ln(b/a) solve for a		2004-12-01
		From Daniel: I am trying to make "a" the subject of this equation "e = ln(b/a)" but am not sure if i'm doing it right. Any help would be appriciated, Answered by Claude Tardif.
	The volume of a sphere		2004-11-30
		From Lyndsay: twenty cubic metres of air are pumped into a spherical hot air balloon with each given diameter: 1.0m; 2.0m; 3.0m; 4.0m; 5.0m;6.0m a)calculate the new diameter, new suface area, and new volume of each balloon. Answered by Penny Nom.
	The substitution method		2004-11-28
		From A student: I Was working and i ran into this problem can you help me solve it using the substitution method? -3x-2y=-10 x+5y=-27 Answered by Penny Nom.
	The tangent line at an inflection point		2004-11-28
		From Louise: the equation of the tangent line to the curve y = x3 - 6x2 at its point of inflection is... Answered by Penny Nom.
	Computing confidence intervals		2004-11-26
		From Christie: I was given a question with N=100, sample proportion is 0.1- compute the 95% confidence interval for P? I have tried this several ways but do not know how to do without means, standard deviations, standard error of the mean? I asked my teacher and she said I have all the info I need. Can you help???? Answered by Penny Nom.
	A right triangle		2004-11-24
		From Bruce: In triangle ABC. Angle ABC is 90 degrees. Side AB measures 34. Side BC measures 31. What does side AC measure? Answered by Penny Nom.
	Slicing cubes		2004-11-23
		From Anthony: You are working with a power saw and wish to cut a wooden cube 3-inches on aside into 27 1-inch cubes. You can do this by making six cuts through the cube keeping the pieces together in the cube shape. Can you reduce the number of necessary cuts by rearranging the pieces after each cut? Answered by Chris Fisher.
	Cost before the markup		2004-11-23
		From Norman: the sum of eg $130 includes the markup of 30%. However I need to calculate the percentage to apply to the $130 to assess the cost ie $100. Answered by Penny Nom.
	A graph with certain properties		2004-11-22
		From A student: i was asked as a question in coursework to sketch the graph with the following characteristics: a double root at -3 a pair of imaginary roots an x-intercept at 6 a root at 4 which is not a double root Answered by Penny Nom.
	Combinations		2004-11-22
		From Vivek: Show that 10C0 + 10C1 + 10C2 + 10C3+.....10C10 =1024 Answered by Penny Nom.
	The length of an arc		2004-11-21
		From Daryl: I am tying to find the arc length of a line 6' and the vertex of the arc 1' off of the line. that is all that is known Answered by Penny Nom.
	Is a square a rectangle?		2004-11-21
		From Carol: I am a teacher. In an FCAT sixth grade review test, there was a question to the students to draw a square and then they referred to it as a rectangle. What is the definition that makes a rectangle a square that can be taught to the students without confusing them. Answered by Walter Whiteley.
	Proof by induction		2004-11-20
		From Vic: Problem: Find the first 4 terms and the nth term of the infinite sequence defined recursively as follows: a(1) = 3 and a(k+1) = 2a(k) for k -> 1. Note: Quantities in brackets are subscripts -> means 'equal to or greater than'. Using the recursive formula, the first 4 terms are; a(1) = 3, a(2) = 6, a(3) = 12, a(4) = 24 The nth term a(n) = 2n-1 x 3 (equation 1) Equation 1 must be proven using mathematical induction. This is where I am having a problem. Answered by Penny Nom.
	Solving quadratics		2004-11-20
		From Aaron: Can you solve the following equation (quote the value of x,y and t to 3 sig figs) ((i have changed figures so that i can work through my own example)) x2 + x - 6 = 0 5y2 +19y = 3 10cos2 t + 3cos t = 4 Answered by Penny Nom.
	Construction of a cone		2004-11-20
		From John: I am a builder working on a project where I need to make a cone. It's a right circular cone with 15" base radius and slant angle of 30 degrees. I want to cut it out of flat sheet metal then bring the edges together to form the cone. Is this enough information? Answered by Penny Nom.
	A sequence		2004-11-19
		From Liucy: Find the Nth term: 10 40 90 160 250 Answered by Penny Nom.
	Volume of a box		2004-11-18
		From Catherine: I need to find a formula to calculate the amount of liquid would hold. maybe the volume or something. its a square box used to hold liquid on a farm . we want to measure how much liquid it can hold. Answered by Penny Nom.
	1/4 tsp salt = ??? grams		2004-11-16
		From Julie: if i have 1/4 teaspoon of salt how many grams does that equal Answered by Penny Nom.
	Equations involving radicals		2004-11-16
		From Merin: I am quite confused about solving radical equations. This is what I understand: ___ V x-3 = 3 Then you would square each side to get ride of the radical sign and then you solve the problem from there. (x=12 right?) However, what about a problem with two radicals? For example: ___ ____ V x-2 + V 3x-3 = 3 No matter what I try I cant get the right answer!! Please help!!! Answered by Penny Nom.
	Interior and exterior angles of a polygon		2004-11-16
		From Aaron: How do you find the measure of interior and exterior angles of a regular polygon when you are given the number of sides? Answered by Walter Whiteley.
	Planting trees		2004-11-15
		From Heather: Design a plan of how it would be possible to plant 10 trees in 5 rows, and have 4 trees in each row. Answered by Penny Nom.
	A fixed point problem		2004-11-14
		From Bob: I am trying to solve an existence of fixed point problem. I need to show that a function f (on reals) with f'(x)=>2 has a fixed point. Answered by Claude Tardif.
	An ODE		2004-11-10
		From David: I have a question that i really cant do, it is as follows: The ODE dy/dx + 0.5y = 0.5e^(-1.5x) ; y(5) = 2 Solve the ODE subject to the given condition using exact methods and evaluate the solution y for x = 5 x=5.2 x=5.4 x=5.6 x=5.8 x=6 Answered by Harley Weston.
	Order of operations		2004-11-10
		From Andrew: I'm trying to solve this question, and I can't seem to remember the rules back from my high school days. (40 x 8 ) / 2 + 55 - 15 = Can you help me with the answer? Answered by Harley Weston.
	A 40% reduction		2004-11-10
		From Cathy: I'm having trouble figuring out how to figure a percentage??? it's easy to find what 40% of any given number is, but how would i accurately figure out what is the final number is when i know the number after the 40% has been removed? when i add 40% to this number it obviously is lower than it should be. the best i could figure is; x=?-40% ---------------> x-?=-40% i'm all confused???? Answered by Penny Nom.
	Bedmas		2004-11-09
		From Fariha: i have a single line question and am not sure of the method it would be appreciated if u could send me a method and a solution Q : 1 + 9 / 2 + 5 * 1000 would this be solved by BEDMAS? if not, why? Answered by Penny Nom.
	A standard deviation test		2004-11-09
		From Karen: How do you compare to see if a sample standard deviation is different than the population standard deviation? I know how to compare means, but not standard deviations. Answered by Penny Nom.
	A 30-60-90 triangle		2004-11-09
		From Amy: How do you find the length of the hypotenuse of a 30-60-90 triangle when the side opposite the 60 degree angle is 6 inches? Answered by Penny Nom.
	Factoring		2004-11-09
		From Rise: Q1: a2 + 5a + 6 I didn't really understand the purpose of the teacher's steps, but was able to get my daughter to find factors of 6 and then add them together to find which resulted in the sum of 5. Unfortunately, this problem-solving technique did not help us to solve for the more complex problems as follows: Q2: 9a3 - 24a2 + 12a Answered by Penny Nom.
	The lcm of 5, 3, 4, 7 and 2		2004-11-05
		From Christine: what is the lcm of 5,3,4,7,2 Answered by Penny Nom.
	42.5 is what % of 170?		2004-11-05
		From Dawn: 42.5 is what % of 170? Answered by Penny Nom.
	The points of intersection of two graphs		2004-11-05
		From Benjamin: How do I find the points of intersection of the two functions: 1) y = 2 - e-x 2) y = 1 + x2 Answered by Harley Weston.
	Probabilities in poker		2004-11-04
		From Ben: Please can someone tell me the odds of getting a royal flush while playing texas hold em. Please can you also let us know the odds of a royal flush while playing texas hold em if you must be dealt two of the needed cards. Answered by Chris Fisher.
	The least common denominator		2004-11-03
		From A student: Write the LCD for each pair of fractions. 13. 1/3,1/5 14. 2/7,1/4 15. 3/4,3/5 Answered by Penny Nom.
	The lcm of 1 and -1		2004-11-03
		From Nayiyan: I would like to know what is the LCM of (-1) and (+1) is. Answered by Penny Nom.
	Adding 3% to get 120,000		2004-11-02
		From Shaun: I was asked a question by a friend of mine's kid. He asked me if you had a final figure of say 120,000, how do you work out the amount you started with if you added 3% of the starting amount, to the starting amount to get the 120,000. Answered by Paul Betts.
	Tennis balls and probability		2004-11-01
		From Jeremy: I have a hopper of tennis balls that contains 25 new tennis balls and 10 old tennis balls. In the hopper the tennis balls are mixed up randomly. If i take one ball out of the hopper and hit it and then put it back and then take another ball out of the hopper and hit it and put it back, what is the probability that i hit two new tennis balls? Also a tennis ball becomes old after being hit just once. Answered by Penny Nom.
	The sides of a hexagon		2004-11-01
		From Timothy: I have a perfect Hexagon in which i know the measurement across is 10m. Not from point to point, but from the middle of one side directly across to the middle of the other. From that measurement, how can I determine the length of 1 side. Answered by Penny Nom.
	Multiplying two algebraic fractions		2004-10-31
		From A parent: Multiply: x+2 x²-4 ----- x ------- x-2 x²+x-2 Answered by Harley Weston.
	Imaginary roots of a ploynomial		2004-10-31
		From Jennifer: how to find the roots of a polynomial equation if it would be imaginary? Answered by Harley Weston.
	GCD and LCM		2004-10-31
		From Cartalina: how do you calculate the "positive difference between the GCF and LCM of two numbers"? Answered by Penny Nom.
	The combined force of two vectors		2004-10-30
		From Brian: Two teams are playing push ball with a large 8 foot diameter ball. One team exerts a force represented by the vector a = 2i + -5j, and the other team exerts a force represented by the vector b = -8i-3j. 1.Determine the direction of movement of the ball if the i axis is due east. 2.Determine the combined force magnitude. Answered by Harley Weston.
	Solving triangles		2004-10-30
		From Allen: Solve the following triangles. Given 1. B = 20 Degrees, a = 25, b = 16 2. A = 35 Degrees, b = 2, c = 3 3. A = 32 Degrees, C = 44, c = 20 Answered by Harley Weston.
	Vectors in three space		2004-10-30
		From Jo: I have two questions that I just cannot visulise and dont know how to get started on them..! 1. Ship X is sailing North at 4m/s and Ship Y is sailing due East at 3m/s. A sailor on Ship X climbs a vertical pole at 1/2 m/s. What is the velocity of the sailor on Ship X relative to an observer on Ship Y? State it's magnitude and direction. Not sure where to start with this one... 2. Show, using vectors, that for any tetrahedron, the segments joining the midpoints of the opposite edges are concurrent. i know what a tetradedron is, and what I am proving but do I solve simultaneously for a specific case?? Answered by Walter Whiteley.
	Bedmas		2004-10-30
		From Gina: I am just curious whether Bedmas would be used in the following question as it is not in the typical Bedmas format. Multiply 12 x 24 Add 26 Divide by 2 Subtract 7 Would we go about doing it in the sequence it is given or in Bedmas ? Answered by Penny Nom.
	The force of a 5000 tonne lorry		2004-10-27
		From Aaron: A 50 tonne lorry is parked on a slope with a gradient of 4%. Due to the self weight of the lorry, what is the force * acting down the slope * acting normal (at right angles) to the slope Answered by Penny Nom.
	Ratios and rates		2004-10-27
		From Kenneth: What is the difference between a ratio and a rate? Answered by Penny Nom.
	Cube roots		2004-10-26
		From A parent: How do you solve the problem of finding the cubed root of (17 to the power of 3). Can you show me each step and if you have a visual representation of this it would be very helpful. Also can you show a step by step of finding the cubed root of 27. Visuals help a lot Answered by Penny Nom.
	20 Golfers		2004-10-26
		From Ian: I have 20 golfers playing over 6 days I would like to schedule all 20 golfers in 5 groups of 4 on each day here is the catch.... I would like each player to play with each other once during the 6 days. Answered by Chris Fisher.
	The point slope form of a line		2004-10-26
		From Jack: Given a set of ordered pairs, ie (1,1) (2,4) (3,7), how does one determine the rule f(n) other than by trial and error Answered by Penny Nom.
	Largest square inside a circle		2004-10-25
		From Bob: my granddaughter asked what is the largest size square in inches would fit in a 60 inch circle? I believe it to be around 42.3 inches but would like to teach her how to do it mathematically. Answered by Penny Nom.
	Square roots and inequalities		2004-10-25
		From Waheed: Q1. What is the simplest way of finding a square root of any number using just a pen and paper? (I am asking this question because I browsed a few sites a didn't find any method that is simpler than the one I use. so I am just curious.) Q2. Is it possible that you take an equation and turn it into an inequality by performing same mathematical operations on both sides? Answered by Claude Tardif and Penny Nom.
	Converting coordinates		2004-10-25
		From Allen: I am trying to help my son with his home, but I don't remember these conversions. Please help. 1. Convert the following coordinates Cartesian x = 7, y = -24 2. Convert the following coordinates Polar r = 4, theta = pi / 3 Answered by Penny Nom.
	Implicit differentiation		2004-10-24
		From Emily: If x^3+3xy+2y^3=17, then in terms of x and y, dy/dx = Answered by Penny Nom.
	Maximize income		2004-10-24
		From Connie: A company that sells x units of a product generates an income (I, in dollars) which is a function of x. The income generated is described by the equation I = (-1/2)x^2 + 100x. Discuss how to determine the number of units that must be sold so that the company can maximize its income. What is the maximum income? Answered by Penny Nom.
	Practical applications: parabolas and Pythagoras		2004-10-24
		From Connie: Provide two examples of real life objects that incorporate parabolic shapes. Explain the reason why the parabolic shape was used in each object. I need at least one practical application of the Pythagorean Theorem. Answered by Penny Nom.
	Solve for a and t		2004-10-23
		From Justin: How do I solve for "a" and "t" in the equations: 1000t= -4000 + 2000t + (1/2)at^2 1000=2000 + at Answered by Penny Nom.
	An aircraft is flying directly from airport A to airport B		2004-10-22
		From A student: In this question, i is a unit vector due east and j is a unit vector due north. An aircraft is flying directly from airport A to airport B, which is 2000 km from A. The velocity in still air of the aircraft is (150i+50j)km/h and the ground speed is (200i-30j)km/h. Calculate (i) the time of flight, to the nearest min (ii) the direction of the wind. Answered by Penny Nom.
	The last digit of a large exponent		2004-10-20
		From Landon: How can one determine the last digit of a large exponent by hand. I have seen several examples of how to do this by breaking it up into smaller exponents, but is there a formula or some common things to look for? Answered by Penny Nom.
	sin(3A)		2004-10-20
		From A student: Express sin3A in terms of sinA and cosA. Answered by Penny Nom.
	A 40% increase in garage space		2004-10-20
		From Dianna: A bus company recently expanded and no longer has enough room in its garage for all of its buses. Twelve of the buses have to be stored outside. If the company decides to increase their garage space by 40%, this will give them enough room for all of their current buses, plus enough room to store another twelve in the future. How many buses does the company own? Answered by Penny Nom.
	A square footage problem		2004-10-19
		From Jerome: I have a peice of property that is almost a triangle but not exactly about 280 frontage with the side lines at 228 and 237 I was told I had about one acre plus a little, a developer says I have 33,000 sq ft. and I would like to know what the real result is Answered by Penny Nom.
	Manipulating exponents		2004-10-17
		From A student: I was wondering if you can describe the steps in getting the solution to the problem below. I have the solution of 5/3 in the back of a book, but I have no idea how that answer was reached. 2raised to the 100th power + 2raised to the 98th power divided by 2raised to the 100th power - 2raised to the 98th power Answered by Penny Nom.
	The third derivative		2004-10-15
		From Holly: Why would you ever take the third derivative? Answered by Harley Weston.
	A rate of change problem		2004-10-15
		From Frank: Find the rate of change of the distance between the origin and a moving point on the graph of y = x(squared) + 1 if dx/dt = 2 centimeters per second. Answered by Penny Nom.
	Two gears		2004-10-14
		From Lindsay: "There are two gears, a small one on the left and a larger one on the right. The gear on the right makes 1 revolution. The gear on the left makes two revolutions. Suppose the gear on the right is turned through an obtuse angle. Will the gear on the left make a full turn?" Answered by Penny Nom.
	Divisibility by 7 and 11		2004-10-13
		From Tammy: I'm stuck in class in Yr 7 And I'm finding it hard on our new topic Divisibility! When I try to find out what this means on Internet sites i can not understand the used symbols like algebra and so on. I'm stuck on the divisibility rules for the number 11! Answered by Penny.
	$25,000 at 11% per year		2004-10-13
		From A student: suppose u have $25,000 to invest and the interest rate at your bank is 11%. 1) how much money would you have at the end of EACH of the first four years? 1) i already kno that the first year w/ interest is $27,750 but how do i get the 2nd? 3rd? 4th? years? Answered by Penny.
	Pythagoras in everyday life		2004-10-13
		From Tiffany: I was wondering if you have any real-life uses of the pythagorean theorem that you use in your everyday life. Answered by Penny Nom.
	Cycling in the wind		2004-10-11
		From A student: A cyclist is travelling in the direction of 12i+5j at a speed of 39 km/h where i is a unit vector due east and j is a unit vector due north. The wind appears to the cyclist to be blowing with a velocity of (-4i+j) km/h. Find, correct to 1 d.p (a) the true speed of the wind and (b) the bearing from which the wind is blowing Answered by Penny Nom.
	An Octagon		2004-10-10
		From A parent: I am trying to determine what the size of each triangle is of a 12 foot circle consisting of 8 triangles would be. I've gotten as far as the radius being 6 feet, but cannot figure the distance. Answered by Penny Nom.
	A five digit number		2004-10-06
		From A parent: What is the 5 digit number in which the first 2 digits are the square of the 3rd digit and the last 2 digits are the square of the digit that is one less than the third digit? The sum of all the digits is 22. Answered by Penny Nom.
	A common tangent line		2004-10-05
		From Shanup: The x-axis is a common tangent of y = x^2 and y = x^3. Find the equation of another common tangent. Answered by Penny Nom.
	Direct and inverse variation		2004-10-05
		From Abraham: Given that y varies inversely as x and x varies directly as z.If z is doubled then y is halved.Why is that true.Please explain.I'm having trouble understanding the different types of variation Answered by Penny Nom.
	Accelerating to the speed of light		2004-09-30
		From Lars: How long time would it take to accelerate up to the speed of light with an acceleration speed similar to 0-100 seconds in 5 seconds? Answered by Penny Nom.
	A mixture problem		2004-09-30
		From Abraham: A chemist has one solution that is 35% pure acid and another solution that is 75% pure acid. How many cubic centimeters of each solution must be used to produce 80 cubic centimeters of solution that is 50% acid? Answered by Penny Nom.
	A theorem involving a trapezoid		2004-09-29
		From Abraham: Given:Trapezoid ROSE with diagonals RS and EO intersecting at point M Prove:Diagonals RS and EO do not bisect each other. Answered by Harley Weston.
	The area of a lot		2004-09-29
		From Deb: I am trying to figure out how many square feet are in a piece of property. Start at Point A-then go 140 feet north-then 100 feet due east-then 300 feet at an angle southeast so that connecting to point A would be a straight line (right angle to first line north.) Answered by Penny Nom.
	Visitor wins or home wins		2004-09-29
		From Paavn and Laddi: I have a math question i am stumped on for one of my classes. The question states that there are 14 baseball games with 2 possible outcomes for each game, visitor win or home win. How many different total combinations are possible from the 14 games? Answered by Penny Nom.
	Cubic yards of concrete		2004-09-29
		From Tanya: We are starting up a new business and for the business we will be required to order concrete for various shapes. Right now we have a job that requires a concrete slab that a decagon it is 140-3/4" from flat side to flat side, 74" from point to center and each flat side is 46" The pad should be 4" thick with 12"x12" continuous footing. Answered by Harley Weston.
	The area of a lot		2004-09-28
		From Stan: I own a parcel of land (lot 20) that is assessed at 9127.00 square feet and has a frontage of 99.90 feet according to the tax roll. I don't know how large my property actually is since I feel that the tax assessment and the survey map don't jive Answered by Harley Weston.
	A palindrome question		2004-09-28
		From Lilly: 12, 21, 13, and 31 are the only double-digit numbers whose squares are the palindromes of the squares of the palindromes of double-digit numbers. I was wondering why it works for these numbers, and if only these numbers work this way. Answered by Chris Fisher and Penny Nom.
	The length of a rectangle		2004-09-26
		From Rebecca: My question is each side of a square S is 18 inches long and the area of S is at least 3 times the area of a rectangle that is 9 inches wide. What is the greatest possible length in inches of the rectangle? Answered by Penny Nom.
	37%		2004-09-26
		From Andrew: how do we change 37% into a fraction Answered by Penny Nom.
	Grams to milliliters		2004-09-25
		From Emily: I am trying to convert 19.5g into mL assuming that it's water; density=1g/mL. I don't know where to begin. Answered by Penny Nom.
	A parallelepiped		2004-09-25
		From Aman: " If OA, OB, and OC are three edges of a parallelepiped where O is (0,0,0), A is (2,4,-2), B is (3,6,1), and C is (4,0,-1), find the coordinates of the other vertices of the parallelepiped.)" Answered by Penny Nom.
	The last digit of 2^28		2004-09-25
		From A student: I am currently enrolled in a math reasoning class and a math question I have to answer is determine the units digit in 3 28power. When I set up a table and keep cubing the numbers, I find a pattern with the last digits of the numbers that follow 1,3,9,7. My calculator gets to about the 19th power, and then I get an error. If I continued the pattern, would the units digit then be the last digit of 3 28th power, which would be a 7? Please let me know if I am solving this correctly and what a unit's digit actually is. Answered by Penny Nom.
	Rational expressions		2004-09-24
		From A student: In general, I understand rational expressions except when it comes to solving problems such as: x+y/2x-y - 2x/y-2x or m-4/3m-4 + 3m+2/4-3m I am confounded by the issue of having to find a common denominator. For example, if I tried to solve these problems by multiplying both denominators they would still be uncommon. Answered by Claude Tardif.
	Supplementary angles		2004-09-23
		From Rosemary: Is the term supplementary angles only applicable to 2 angles (ie. a pair of angles) or can it be used when talking about 3 or more angles that add to make 180 degrees? Answered by Penny Nom.
	Incremental variance		2004-09-23
		From Carlos: I must keep statistical data (mean and variance) in 3 granularity levels depending on the age of the data (daily for older than 1 year, hourly for older than 1 month and quarter-hour for older than 1 day). How can I calculate the resulting variance from a set of variances previously calculated supposing I have the count and mean for each member of the set? Answered by Andrei Volodin and Penny Nom.
	The volume of a pile of mulch		2004-09-22
		From Sam: Is there a formula to determine the cubic feet of something in a pile. IE- I need to determine the cubic feet of a pile of mulch. The pile comes to a peak, so the length and width decrease as the pile increases. Answered by Penny Nom.
	Four and five digit numbers		2004-09-21
		From Josy: The question I have now in front of me is....Is a 4-digit number always less than a 5-digit number? Hi Josy, The digits in order are 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Thus the largest four digit number is 9999. The smallet 5 digit number is 10000. Penny Go to Math Central Answered by Penny Nom.
	1,3,6,11,18,29,__		2004-09-21
		From Guillermo: How do you get to the answer of this sequence 1,3,6,11,18,29,__ Answered by Claude Tardif.
	f(x) = x-4 if x<2		2004-09-21
		From Dani: Hi, my name is Dani. I'm in tenth grade Algebra 2, and I'm learning about a lot of different kinds of functions, and I can't quite seem to understand how every part of the piecewise function works. I understand most of it, I think, but I've been looking at an example in my math book, and I'm not sure how they got the answer they did. The part I don't understand reads: "Graph f(x) = x-4 if x<2" and "Identify the domain and range." The picture in the book shows an open circle at (2,-2), with an arrow going down and to the left with the slope being one. How did they get the open circle to be at (2,-2), and why does the arrow point where it does? Answered by Penny Nom.
	The method of substitution		2004-09-20
		From Kayla: y=x-1 y=2x-3 Answered by Harley Weston.
	Wages for one month		2004-09-20
		From Janet: if offered $10,000 or 1 cent on the first day and then doubled daily for one month which would you take ? Answered by Harley Weston.
	B={A,{A}}		2004-09-20
		From Muhammad: Let A be a set and let B = {A,{A}}. (a) Explain the elements of set B (with some example) (b) Prove that A is not a subset of B. Answered by Penny.
	The hypotenuse of a right triangle		2004-09-20
		From Shannon: I am trying to find the hypotenuse of a right triangle with only the length of the opposite side. What is the formula as I don't have the length of the adjacent side? Can I compute it without knowing what the other two angles are? Answered by Penny Nom.
	Fabricating with pipe		2004-09-19
		From Gil: I need to fabricate a 10 section, 4" pipe circle with an inside diameter of 40". I would like to know what angles would apply and how to find them, Answered by Penny Nom.
	A binomial squared		2004-09-19
		From John: Can you explain the steps for me, that get you from (a - b)2 to a2 - 2ab + b2 Answered by Penny Nom.
	Perimeter and area of a semi_circle		2004-09-18
		From A student: I want to know how to find the perimeter and area of a semi-circle and a quarter-circle. Answered by Penny Nom.
	Zero to the zero		2004-09-18
		From Greta: My name is Greta, and I am a 7th grader and my test is coming up. The question I would like to ask you is why 0 elevated to 0 is unidentified. Answered by Penny.
	Driving me crazy		2004-09-18
		From Jerry: This is driving me crazy!!! Someone told me of a number that can be divided EQUALLY by each of the following individual numbers: 1,2,3,4,5,6,7,8,9. what is that number? Answered by Penny.
	The price of a book		2004-09-18
		From Dorly: If the number of toonies required to buy a book is nine more than the number of five-dollar bills required to buy the same book, determine the cost of the book. Answered by Penny.
	A challenge		2004-09-17
		From Lasse: xy xx xyx xxx xyxx "x" and "y" each represents a number. Find out the system to make the next line Answered by Penny Nom.
	Some numbers less than 100		2004-09-17
		From Paul: for how many numbers less than 100 is the digit in the ones place half the digit in the tens place? Answered by Penny Nom.
	Division with and without units		2004-09-17
		From Kenneth: What does it indicate when the divisor has units (dollars) but not the dividend, as in 500/$10.00 or 500 is divided by $10.00? Are the units understood to be there? Does 500/$10.00 make sense? Answered by Penny Nom.
	The length of a cut		2004-09-17
		From Florita: My daughhter, who is a 9th grader is attempting to cut a piece of wood after determining the length of the cut for the hypotenuse. These are the measures: a=4squared, b=6squared. She determined that c should equal 52. But when she measured the actual piece to be cut, c measured 39.5 inches! Can you offer any insight as to what she is doing wrong? I have suggested that she may be working with an Acute rather than a Right angle . But she insists that it is a Right angle after using a "framing square". Answered by Claude Tardif.
	Pizza for Jack?		2004-09-16
		From Grace: Jack is playing pool with Jim for $1 a game. He has only $2 and decides to play until he goes broke or has $5, at which point he will quit and go out for a pizza with Jim(Dutch treat). Jack knows from past experience that he beats Jim 60% of the time. What is the probability that Jack will get to eat pizza? Hints: Let A be the 6x6 matrix defined by A=[aij], where aij is the probability that Jack will have $(i-1)after one game is he starts with $(j-1). For example, a23 - .40 since there is a 40% probability that Jack will end up with $1 after a game is he starts the game with $2 (If Jack wins 605 of the time, he must lose 40% of the time). Also, for example, a52 = 0 since there is no way jack can have $4 after one game if he had $1 at the beginning of the game. Since Jack will stop if he goes broke or accumulates $5, a11 and a66 are both 1. Let x0 = [0 0 1 0 0 0 ] transposed, which we interpret as saying that initially Jack has $2 with a probability 1. Then Ax0 will represent the porbability of each amount of money, $0-$5, after one game. What is the probability that Jack will be able to eat pizza by computing Akx0 for large k and finding a limiting value. Answered by Penny Nom.
	Volume		2004-09-16
		From Jonathan: I have an area of 22ft x 43 ft, 6 inches high Sq. ft..946 sq. yds...105.1 What is the cubic feet and cubic yards for this dimension. Answered by Penny Nom.
	S is between T and V		2004-09-16
		From Reuben: S is between T and V. R is between S and T. T is between R and Q. QV=18 QT=6 and TR = RS = SV Make a sketch and answer the following: Find RS QS TS TV Answered by Penny Nom.
	The game of 24		2004-09-16
		From Angelica: how can you make 24 out of 7,7,6,5? Answered by Claude Tardif.
	Finding the height of a triangle		2004-09-14
		From A student: I have to calculate the height of a triangle. The base is 6 (units)say ab One of the top sides is 4 (units)say ca The other side is 2 (units) say cb I don't know the angles. How to find the height? Answered by Chris Fisher and Penny Nom.
	The game of 24		2004-09-14
		From Alan: I was playing that math 24 game and i cant get 21,14,2,2 to equal 24 Answered by Claude Tardif.
	Crossword math puzzle		2004-09-14
		From Joyce and Tiffany: The puzzle name was real number vocabulary and the question is (a number that divides evenly into another what is it?). (Space in between tic-marks on a number line). Answered by Harley Weston.
	Payment plus interest		2004-09-14
		From Penny: Brian wants to borrow some money from Margaret. After three years he is to pay X back plus one interest sum of 25%. If he is pays back a total of $3800, what was the original sum borrowed? Answered by Penny Nom.
	differentiate Y=X^X^X		2004-09-13
		From Kunle: differentiate Y=X^X^X Answered by Penny Nom.
	Making a pyramid		2004-09-12
		From Jacob: My name is Jacob and I am a 11th grade student trying to build a pyramid for a friend but I need a chart of some sort to show me the measurements (I learn better w\pictures) it is a square base with 18 in sides and I want the vertex to be 18in above the base I need to know as many measurements as you can give me. Answered by Penny Nom.
	A copper sphere		2004-09-12
		From Irfan: The radius of a copper sphere is 3cm. If a wire of 0.4 diameter is drawn by melting it,what is the length of this wire? Answered by Penny Nom.
	Three word problems		2004-09-12
		From Adrian: 1. Increasing area of a field: Julia's soybean field is 3m longer than it is wide. To increase her production, she plans to increase her to increase both the length and width by 2m. If the new field is 46m2(2nd power) larger than the old field, then what are the dimensions of the old field? 2. Width of a Football Field: If the perimeter of a football field in the NFL including the end zones is 1040 ft and the field is 120 yd long, then what is the width of the field in feet? 3. Fencing dog pens Clint is constructing two adjacent rectangular dog pens. Each pen will be three times as long as it is wide, and the pens will share a common long side. If Clint has 65 ft of fencing, what are the dimensions of each pen? Answered by Penny Nom.
	Number combinations		2004-09-10
		From Angela: I need the number of possible number combinations, both 3 and 4 digit, from 0-59 I know that 0-9 has 10000 combinations for 4 digits I also know that 0-9 has 1000 combinations for 3 digits Perhaps you could explain an easier way to figure this out rather than writing all these numbers down?? Answered by Penny Nom.
	A schedule for 6 teams		2004-09-10
		From Greg: I have a schedule I need to make of 6 teams. They must play each other once however no team can be the away team twice in a row. There must be 3 home games and 3 away games for each team. Answered by Penny Nom.
	105.6 is a discount of 12% from x		2004-09-10
		From David: If I know that 105.6 is a discount of 12% from x, how do I find x?? Answered by Penny Nom.
	1+3+5+...+(2n+1)		2004-09-10
		From Emma: Prove that 1+3+5+...+(2n+1)= (n+1)2 Answered by Penny Nom.
	Safe cracker		2004-09-09
		From Adam: Franklin's friend had taken an item from him, and put it in his family's safe, when franklin went to retrieve it he came to a combination lock on the safe, with the dial numbers going from 0 to 59. Unfortunately, he wasn't sure whether there were three or four numbers in the combination, or even which direction to turn the wheel If it takes him 15 seconds to try a single combination, how many days will it take him to to try every possible combination? Please round to the nearest day. Answered by Penny Nom.
	The 24 game		2004-09-09
		From Erik: Ive spent around 40 hours on this one problem. I need help. 3,3,7,7 Answered by Claide Tardif.
	A travelling salesman		2004-09-09
		From Liz: A salesman traveled due west from city A to city B. The distance he traveled, that is the ditance from A to B, was X miles. He returned from B to A and found that he had traveled half the distance, X/2 miles. How can that be? Answered by Chris Fisher and Penny Nom.
	Crossing a river		2004-09-09
		From Barb: Nine men and two boys, trekking through the jungle, need to cross a river. They have a small inflatable boat and it's easy enough to row it across the river. The boat, however, can hold no more than one man or the two boys. How can they all get across? (Hint. suppose there was only one man and two boys) Does it make math sense and what would the answer be Answered by Penny Nom and Claude Tardif.
	An inverse		2004-09-09
		From Hillary: I cannot figure out the inverse of this function. f(x)= 1/2x -1 Answered by Penny Nom.
	Half way between		2004-09-08
		From Ben: Find the number halfway between the number shown 751,843 Answered by Penny Nom.
	The nth term		2004-09-08
		From Alex: What is the nth term?... Like what is it?, How do I find it?, and how exactly is used?... Answered by Penny Nom.
	d varies inversely with g		2004-09-07
		From Ashlyn: d varies inversely with g when d=-8 and g=2 a. write d as a function of g using function notation. b. find d(10). Answered by Penny Nom.
	Constructing a cone		2004-09-07
		From Steve: I am trying to build crayfish traps; one of the components is a cone shaped entry section. The cone I want to make would be 12" in diameter at the base and 12" in height, from base to peak. I need a formula to calculate the dimensions and a method of transferring the shape onto a flat piece of material. Answered by Harley Weston.
	The intersection of planes		2004-09-07
		From Joshua: I was wondering about the intersection of planes. Can planes intersect? Answered by Penny Nom.
	The bar over repeating digits.		2004-09-07
		From Debbie: I would like to know the name given to the bar that is written over the repeating digits of a decimal. Answered by Penny Nom.
	How to dry matches		2004-09-06
		From Liz: The neighbors of a young man who needed seclusion for a few days offered him the keys to their cabin in Maine. Arriving there on a damp and cold autumn evening he saw that while the cabin had normal running water and electric lights, for heat it had only a pot-bellied stove. Fortunately, there was plenty of wood, kindling, newspaper, and matches. Being an experienced hand at making a fire, he opened the damper, put into the stove crumpled newspaper, and properly stacked the kindling and logs. The matches, however, wouldn't light. They were too damp from the humidty. The nearest town was 30 miles away, and, anyway, it was late. What next? Answered by Claude Tardif.
	(2x+5y-6) + (3x-4y+12)		2004-09-04
		From GG: I am a grade 9 student and i do not understand a question. Plz help! OK here it is........ (2x+5y-6) + (3x-4y+12) Answered by Penny Nom.
	Order of operations		2004-09-04
		From Leanne: 6 + 3 - 2 x 3 = Answered by Claude Tardif.
	The distance formula		2004-09-04
		From Joe: Why do we use square roots and squares in the distance formula Wholdnt they cancel each other out? Answered by Claude Tardif.
	Nine minutes		2004-09-02
		From A student: You have two hour glasses-one measures 7 minutes and one measures 4 minutes.How can you time 9 minutes? Answered by Penny Nom.
	Cubic yards		2004-09-01
		From Garnet: I have the dimensions of 16 feet by 10 ft and 3 1/2 inches deep how much concrete do I need. Answered by Penny Nom.
	An isosceles trapezoid		2004-08-31
		From Bruce: An isosceles trapezoid with bases of lengths 12 and 16 is inscribed in a circle with a radius of 10. The center of the circle lies in the interior of the trapezoid. Find the area of the trapezoid. Answered by Penny Nom.
	Cubic meters		2004-08-31
		From Brad: I have a 10' x 10' x 12" area & need to find the cubic meters, how do I do this? Answered by Penny Nom.
	Percentage change		2004-08-30
		From Lauren: if egg A weighed 55.4g and after 2 days it weighed 60.9g how could i calculate the percentage change in weight? Answered by Penny Nom.
	Solve for z		2004-08-30
		From Ana: Solve for z when 4x + 10yz = 0 solve for z if y2 + 3yz - 8z - 4x = 0? Do I have to solve all of the variables in order to get z? Answered by Penny Nom.
	69 is what percentage of 113		2004-08-28
		From Mary: How do I work out what percentage of 113 69 is? Answered by Penny Nom.
	GCD (a + b , a^2 - ab + b^2)		2004-08-27
		From Carol: Let a and b integer and relatively prime. Proof that: GCD (a + b , a^2 - ab + b^2) = 1 or 3 Answered by Penny Nom.
	A big number		2004-08-26
		From Mark: If you have $999,999,999,999,999,999,999,999,999,999.99 and you find a pennie how much is that and can you give me the name of it. Answered by Penny Nom.
	Combined operations		2004-08-26
		From Louise: Question 2 1/4 x 1/8 / 1 3/4 x 12 4/9 x 3 = Answered by Penny Nom.
	Percentage of a quota		2004-08-26
		From Jenni: I have the year to date sales of $2,042,744 and the quota is $2,257,440, how do I figure the percent quota. Answered by Penny Nom.
	The area of a quadrilateral		2004-08-25
		From Rich: I would like to know how to measure the area (the formula) of a quadrilateral. Answered by Penny Nom.
	The radius of a circle		2004-08-24
		From Peter: If you slice any circle with a line, and call the distance of the line between intersections the "y" length and the perpendicular length to the shorter side of the curve the "x" length, what is the resulting equation for the radius? Answered by Penny Nom.
	50/5x - y		2004-08-22
		From Rick: Niece has a question that was marked wrong but we are unable to determine how the teacher calculated and arrived at the answer? The problem was as follows: 50 / 5x - y = x=5 y=1 Answered by Harley Weston and Leeanne Boehm.
	The area of a lot		2004-08-22
		From Cassie: I'm in the process of purchasing some land and I'm trying to figure out the square footage of the property. Unfortunately, it's be a while since I had to remember this type of formula. The property is 140 ft on left side, across the back it is 220.61 ft, the right side is 167.52 ft, the frontage is 105 ft. Answered by Penny Nom.
	15 cubic yards of dirt		2004-08-22
		From Barry: My question...what is the equivalent of 15 cubic yards of dirt? Answered by Penny Nom.
	130 cc. is ?		2004-08-20
		From Ayrn: 130 cc. is ? I have to put 130cc. of petroleum in a bucket how much exactly is that? Also 110 cc.? I have to also put 110cc. wood alcohol in a bucket aswell! Answered by Penny Nom.
	Golfing with Norm		2004-08-19
		From Norm: I am organizing a golf tournament with 6 American and 6 Canadian players. We play 3 rounds of golf. Is there any way to arrange that everyone plays without playing with the same person twice. Each foursome must consist of 2 Americans and 2 Canadians with one of each in a cart. Your help would be much appreciated. Answered by Claude Tardif.
	Golfing with Sally		2004-08-19
		From Sally: We are a group of 8 golfers (2 foursomes) and want to golf 3 games together. How can we arrange it so that we all get to golf with each other at least once? At another venue, we have 18 golfers (3 foursomes, 2 threesomes) and want to golf 6 games together. Same question, how can we arrange it so that we all get to golf with each other at least once? Answered by Claude Tardif.
	A division symbol		2004-08-18
		From William: i was wondering what the mathematical name for this division sign (÷). Answered by Penny Nom.
	A cube is inscribed inside a sphere		2004-08-18
		From A student: A cube is inscribed inside a sphere with radius sqrt8cm. Find the (a) length of the cube (b) volume of the space inside the sphere but outside the cube. Answered by Penny Nom.
	The series from i=1 to n :ai		2004-08-18
		From Ken: a.) Explain the difference between the series from i=1 to n :ai and the series j=1 to n :aj b.) Explain the difference between the series from i=1 to n:ai and the series from i=1 to n :aj Answered by Penny Nom.
	Area of a triangle		2004-08-17
		From Barkie: I'm going into tenth grade and I have a triangle who's sides measure 3ft, 4ft, and 5ft. I need to find the area however I don't know the height, or how to get it. Answered by Chris Fisher.
	Two water jugs		2004-08-16
		From A student: You go to a source of water with two jugs and only two jugs. One jug has a capacity of exactly three pints and the other five pints. Both jugs are opaque (you can`t see inside them) and irregularly shaped. You have no other water containers. You do not have a scale. How can you use the two jugs and only the two jugs to measure exactly four pints of water? Answered by Penny Nom.
	Percentiles		2004-08-15
		From Gary: Table 1 Selected percentiles for family income in the US in 1992 1 $1,300 10 $10,200 25 $20,100 50 $36,800 75 $58,100 90 $85,000 99 $151,800 Q. The percentage of families in Table 1 with incomes below $58,100 was about? Answered by Penny Nom.
	A probability question		2004-08-15
		From Gary: In a law school class, the entering students averaged about 160 on the last LSAT; the standard deviation was about 8. The historgram of the lLSAT scores follwed the normal curve reasonable well. Q. About what percentage of the class scored below 166? Q. One student was 0.5 above average on the last LSAT, about what percentage of the students had lower scores than he did? Answered by Penny Nom.
	X is due north of Y ...		2004-08-11
		From A student: X is due north of Y and 2km distant. Z is due east of Y and has a bearing of S35°12'E from X. How far, to the nearest metre, is Z from X? Answered by Penny Nom.
	Cubic yards of dirt		2004-08-11
		From A parent: How many cubic yards of dirt would it take to fill an area that is 325 feet by 325 feet and is 3 feet deep? Answered by Penny Nom.
	Acres and miles		2004-08-11
		From A student: How many acres are in 1 mile? Answered by Penny Nom.
	2.79 acres		2004-08-11
		From Helen: What would the square footage be of 2.79 acres? Answered by Penny Nom.
	Area of a hexagon		2004-08-10
		From RB: Hello. I need to find the Area in sq. ft. of a Hexagon with 6 equal sides, of 26' each. Answered by Penny Nom.
	A conic		2004-08-10
		From A student: My question is about this equation 32x*2 -18y*2 -64x +72y +248 =0 explain why as x goes to the infinity the graph of the conic looks like y= (3/4)X. What I did to try to find the solution of this problem was to graph and then I thought that maybe trying to find the equation of the asymptotes I could do it, but it was useless -because the equation of the asymptotes is y= +4/3(X-1) -2 and that does not explain why tho conic looks like y=(3/4) x . I would really appreciate your help on this. Answered by Penny Nom.
	Constructing a triangle		2004-08-08
		From KV: HOW TO CONSTRUCT A TRIANGLE ABC, WHEN ITS ALTITUDES AD,BE,CF ARE GIVEN Answered by Chris Fisher.
	A big number		2004-08-08
		From Carter: Can you tell me what number this is? 10,000,000,000,000,000,000,000,000,000,000,000,000 Where can I find the names for big numbers? Answered by Penny Nom.
	Limits and composite functions		2004-08-07
		From Sue: I have two questions, one about a limit and the other about a composite function. If you could help me, I'd really appreciate it. 1. Find the limit: lim[x->0] (x*csc(x)) I converted csc(x) to cos(x)/sin(x), but I didn't know what to do after that. 2. f(g(x)) = ln(x^2 + 4), f(x) = ln(x^2) and g(x) > 0 for all real x, find g(x): I'm having trouble with this one because x^2 + 4 isn't a perfect square. --Sue Answered by Penny Nom.
	The integrating factor method		2004-08-05
		From A student: Whilst using the integrating factor method, I am required to integrate a function multipled by another function. say f(t) = exp(kt) and some other function g(t); where exp = exponential and k is some constant. Integral f(t)*g(t) dt or Integral exp(kt)*g(t) dt What would the result of this integral be? I have never met an integral like this before. Would it simply be exp(kt)*g(t)/k? More specifically, the problem and my attempted answer is in PDF format: In my attempted solution, I am unsure about the last two lines I have written out, as it relates to integrating a function multipled by another function. Answered by Harley Weston.
	Integrating e^sin(x)		2004-08-04
		From A student: I need to know that how to solve the integral " e^sin x", Answered by Harley Weston.
	Differentiation		2004-08-04
		From A parent: I am a parent trying to understand higher level of maths and would be very grateful if you could help with differentiating the following functions, identifying general rules of calculus: a) f(x)=e^2^xIn(cos(8x)) b) f(x)=secx/SQRTx^4+1 Answered by Penny Nom.
	Two trig problems		2004-08-04
		From Tracie: sin^2x - sin x -12 = 0 sin 2x = -sin x Answered by Penny Nom.
	When is the limit of f(x) undefined?		2004-08-03
		From Nicolasa: When is the limit of f(x) undefined? Answered by Penny Nom.
	an integer with three factors		2004-08-03
		From A student: What is the probability that a randomly chosen 3 digit number has exactly 3 factors Answered by Penny Nom.
	sin^2x-5sinx-3=0		2004-08-02
		From Kerri: hey my name is kerri i'm a college students and i was wondering if you could help in with this problems sin^2x-5sinx-3=0 Answered by Penny Nom.
	A tangent to a hyperbola		2004-08-02
		From A student: The equation of a hyperbola is 32x*2 -18Y*2-64x +72y +248=0. The equation of a tangent line to this hyperbola is y= (16/15)X + 10/3 I have been trying to find the point where this line intersects the graph. What I did was solve for x and then plugged in the result into the equation of the hyperbola, but I am getting two answers and I am supposed to get only one because the line is tangent to the graph. For this reason, I would like to know what I am doing wrong or what I have to do to know which answer is correct. Answered by Penny Nom.
	Two problems		2004-08-02
		From JJ: A question on my homework assignment about logs says "suppose that x=logA and y=logB & write the expression in terms of x and y" log(A - B) Is this even possible? It seems like a typo. Another is: "solve for t." 12(1.221)^t = t + 3 Is this one possible? If it is, I cant figure it out. Answered by Penny Nom.
	A trig problem		2004-08-02
		From A student: Given that the maximum value of [sin(3y-2)]^2 -[cos(3y-2)]^2 is k. If y>7, Find the minimum value of y for which [Sin(3y-2)]^2 - [cos(3y-2)]^2 =k. Answered by Penny Nom.
	Domain and range		2004-08-01
		From JJ: I'm checking domain and ranges of these functions. Are these right? Answered by Penny Nom.
	The law of sines		2004-08-01
		From Joy: How do you solve this? Do you solve this triangle using the law of sines of the law of cosines? (ASA) A=120DEG. B=40DEG c=35 cm I keep getting different answers. Answered by Penny Nom.
	Rate of change problems		2004-08-01
		From Jim: I just want to check a couple average rate of change problems because i just guessed on how to do them. Can you tell me how to do them? the question says if f(x) = sqrt(x + 3), find f( x + rx). I got sqrt( x + rx + 3) the other two are : f(x)= 3x-1 (f(x) - f(1)) / (x-1) ... I GOT 3 & f(x)= x^3 - x (f(x) - f(1)) / (x-1) ... I GOT x^2 + x Answered by Penny Nom.
	Combien de litre y a t'il dans un M3		2004-07-30
		From Un eleve: j'aimerais savoir combien de litre y a t'il dans un M3. car je dois mettre un produit spécial dans une piscine. Answered by Claude Tardif.
	A parallelogram		2004-07-30
		From Keith: I'm a high school student and have been having trouble with this problem , which is based on one pair of parallel sides of a parallelogram: If AD = 6x-5 and BC = 3x+7 find x. Of course both sides have to be equal. Now I know the value of x is 4 So my question is how do you get 4 from the given information. Answered by Penny Nom.
	Extraneous solutions		2004-07-28
		From Nicole: When I have a problem like (2x + 3)/5 = (x + 1)/6 and the question asks to check for extraneous solutions, how do you solve that? Answered by Penny Nom.
	Water in a cone		2004-07-28
		From A student: A vertically inverted cone( i.e. vertex down) has a radius 7 inches and height 24 inches. Water is filled to one third of its height .Find the ht of water when cone is turned upside down Answered by Penny Nom.
	The third side of a triangle		2004-07-28
		From Annette: How do you find the length of a triangle side if you know two sides? Answered by Penny Nom.
	Factoring		2004-07-28
		From Nicole: Can 4x2 + 19x + 12 be factored? i have tried but i cannot figure it out. Is there a way to find out if it cannot be factored before i try to work out the problem? Answered by Penny Nom.
	The intersection of two graphs		2004-07-28
		From JJ: Is there a way to find the intersections of these graphs algebraically? x^2 + y = 4 & 2x - y = 1 I got (1.45, 1.9) and (-3.45, -7.9) with a graphing calculator. AND THESE... y = 3.29x & y = 5.5(x^0.5)+ 10000 I got x at 3133 with a graphing calculator. Answered by Penny Nom.
	x^2 = x + 2		2004-07-26
		From A parent: x2 = x+2 My daughter came home with this equation today and although I know the answer is x=2, i have no way of proving it by showing any working out. Answered by Penny Nom.
	The railing around a pool		2004-07-26
		From Bob: I have a 15' circular above ground pool. Around the perimeter of the pool are eleven (11) sections of railing. Each rail has 5 slots at each end for pins. I have calculated that the length of the arc under the railing to be 51.4". what I am trying to determine is the distance between the end points of the arc so that I can figure out which slot to use in the rails without going round and round the pool moving and removing the rails until they finally fit. Been there, done that, no fun. Answered by Penny Nom.
	The p-value		2004-07-25
		From Kathy: Ms. Lisa Monnin is the budget director for the New Process Company. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information. At the .10 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff? What is the p-value? Having problems finding the p-value & unsure of the formula. Kathy Answered by Penny Nom.
	Row echelon form		2004-07-24
		From Michael: My name is Michael and I'm in the 11th grade. I have a Math question that I can't solve. The problem is system of equations that I need to do in augmented matrix form, find the row echelon form, and solve it by using back substitution. 2x + 3y + 7z =13 3x + 2y - 5z = -22 5x+ 7y - 3z = -28 Answered by Penny Nom.
	The inverse of a quintic function		2004-07-22
		From A student: I'm really having trouble finding out the inverse of this quintic equation. F(X)= X5+3X3+1.I know that this quintic has an inverse because it is one to one. But I can't find a method to solve this. Finding the inverse of a quadratic or a cubic equation is a lot easier, but with this quintc I am really lost. I even know how the graph of this equation and its inverse looks like, but I'm not sure if Iam getting the right equation. Please help me out. Answered by Penny Nom.
	Factoring		2004-07-19
		From A student: Factor completely: 3x3 - 24y3 54x6 + 16y3 16xy - 4x - 4y - 1 0.09x2 - 0.16y2 Answered by Penny Nom.
	The number of blocks in a mile		2004-07-18
		From Valerie: I don't know if you can help me but I was wondering how many blocks are in a mile in Ocean City, New Jersey? Answered by Penny Nom.
	A proof in geometry		2004-07-16
		From An: Im taking a geometry course for the summer , and we just started to learn about proofs for about one week. Today in class, we started to do this one proof but didnt finish it because class ended. the problem is as follows. Answered by Penny Nom.
	Solving some quadratic equations		2004-07-15
		From A student: Could you please solve the following for x x2+6=5x x2+16=8x 2x+21=3x2 Answered by Penny Nom.
	Two vector problems		2004-07-14
		From Jaye: Two force, 120lb and 200lb, act on a body and make a 52 degree angle w/ ea. other. What's the magnitude of the resultant of the forces and what is the measure, to the nearest degree, of the angle that it makes with the 200lb force? Answered by Penny Nom.
	The commuter		2004-07-14
		From JJ: A student who commutes 27 mi. to college remembers, after driving a few minutes, he forgot a term paper. Driving faster than usual, he returns home, gets the paper, and once again starts to school. Sketch the graph of the student's distance from home as a function of time. Does it mean that the student drives at normal speed, drives faster to pick up the paper, and resumes normal speed to head back, or that the student drives at normal speed, then drives faster the rest of the way to college? Answered by Penny Nom.
	12(1.221)^t = t + 3		2004-07-14
		From Jay: This problem has me stumped since i cannot separate the t and the 3. Here it is: 12(1.221)t = t + 3 It's on a logarithm worksheet, but how do i figure it out?! Answered by Harley Weston.
	Two puzzles		2004-07-13
		From Fred: A young man's car developed a flat tire while he was driving along a deserted street. He pulled over to the curb and did all the usual things; removed the hub cap; unscrewed the lugs and rested them carefully in the hub cap, jacked up the car. As he was putting the spare tire onto the axle he accidentally kicked the hub cap. The lugs rolled out, and all five of them rolled down a nearby grate. Peering through the bars of the grate the man thought he could see the lugs about 6 feet below in a shallow water puddle. He had a problem, how do you think he solved it? It is noon, your lunch hour, but you can not go out because there is a terrific hailstorm. Turning on your radio you hear the weathercaster predict that the hail will change to rain and that it will pour all day today. How can you determine the sun will be shining in 36 hours? Justify your answer. Answered by Penny Nom.
	An Octagonal playhouse		2004-07-13
		From Levi: I'm building an octagon playhouse for my son that is 8 feet wide. what would be the measurements of each of the eight sides. Answered by Harley Weston.
	Cubic yards		2004-07-12
		From A homeowner: I would like to know how many cubic yards are in the following; 20 ft wide x 80 ft long x 4 inches thick? I am trying to figure out how much concrete I will need to pour for a driveway. Answered by Penny Nom.
	x = 2^x		2004-07-12
		From A student: If the graphs of y=x and y=2x are drawn on the same set of axes, they will intersect when x is equal to what? (1)1 (2)2 (3)0 (4)They won't intersect. I know the answer is number 4 by graphing which is permitted; however, I would like to know if there is any algebraic way to do this type of problem.If yes, please show me how.Thanks. Answered by Penny Nom.
	Two Problems		2004-07-12
		From Justina: i cant figure out the range of this equation in interval form because the highest point seems to be a decimal. please help f(x) = x + sqrt(4-x2) ............................................................................. Building Design A circular air duct of diameter D is fit firmly into the right-angle corner where a basement wall meets the floor (see figure). Find the diameter of the largest water pipe that can be run in the right-angle corner behind the air duct. Answered by Claude Tardif and Penny Nom.
	The tangent of theta		2004-07-10
		From Jacob: P is a point on a unit circle with coordinates(0.6,0.8). Find tan of theta. My book shows me how to do it,"tan of theta=opp./adj.=0.8/0.6=4/3,"and leaves it as that's the answer(4/3).When do we know from a problem to find the angle measure (in this case, the angle measure of theta) and how do we know when to give something like 4/3 without converting it to the angle measure? Answered by Penny Nom.
	Four digits		2004-07-10
		From Rob: I am always interested to know how the for digit works. I mean, you have correctly put it that the total numbers obtain from 0000 thru 9999 are 10,000. My question is, is there any simple formula to turn this simple 4 figures of say: 1234. Answered by Penny Nom.
	The circle through three points		2004-07-06
		From Jim: I am a student trying to solve math problem. I'd like to calculate the radius of the circle that exactly fits any three points. If the points are (X1,Y1), (X2,Y2), and (X3,Y3), what is the radius of the circle that contains those three points? Answered by Penny Nom.
	Vectors		2004-07-06
		From Annie: a=3i-j+2k and b=i+3j-2k, determine the magnitude and direction cosines of the product vector and show that it is perpendicular to a vector c=9i+2j+2k. Answered by Chris Fisher.
	An ineqlality with absolute values		2004-07-05
		From Uneeza: abs(x2 - 4x) > 3 Answered by Claude Tardif.
	Factoring integers		2004-07-02
		From A student: After looking at all the info I could get about NFS, I still have some questions that are unsolved: First of all: If someone found an algorithm that has a worst case running time of N*Log(N) to factor an integer n into his divisors, would it be quicker or slower then the number field sieve algorithm? secondly, what exactly is the time complexity of the Number Field Sieve algorithm, if I would factor an integer n? Answered by Claude Tardif.
	Choosing 5 numbers from 1,...,36		2004-06-30
		From A lottery player?: how many combinations are there for the numbers 1thru 36 when only using each number once in groups of five Answered by Penny Nom.
	Simplify		2004-06-27
		From Tiff: Simplify: -3x (x2 + 2) (x + 2) (x + 3) Answered by Penny Nom.
	Aunt Lucy's letter		2004-06-27
		From Olivia: "Dear bob, now that i am getting on (70 today). i want to give you some of my money, i shall give you a sum each year, starting now. you can choose which of the following schemes you would like me to use. a) £100 now, £90 next year,£80 the yaer after and so on. b) £10 now, £20 next year, £ 30 the next year and so on. c) £10 now, 1.5 times as much next year, 1.5 times as much the year after that and so on. d)£1 now, £2 next year, £ 4 the year after, £8 the year after and so on. of course these schemes will only operate while i am alive. i look forward to hearing which scheme you choose and why! Best wishes, Aunt Lucy." Answered by Penny Nom and Claude Tardif.
	Undercapatalized small businesses		2004-06-26
		From Greg: Suppose that 30% of all small businesses are undercapitalized. 40% of all undercapitalized small businesses fail and 20% of all small businesses that are not undercapitalized fail. A small business is chosen at random. The probability that the small business succeeds if it is undercapitalized is? Greg Answered by Penny Nom.
	Pick a number greater than 1		2004-06-25
		From A student: I understand that when you pick a number greater than 1 and less than 10; multiply it by 7 and add 23, then add the digits of that number until you get a one digit number. Then multiply that number by 9, add the digits of that number until you get a one digit number, subtract 3 from that number and divide the difference by 3; that this process will always give you the result of 2. Does this have a name or theory for it as to why the answer will always be 2? Answered by Penny Nom.
	(a+b) + 5i = 9 + ai		2004-06-25
		From Josh: The question which someone gave you (a+b) + 5i = 9 + ai question) gave me trouble. Answered by Penny Nom.
	(ln(50/x)) / (ln(40/x)) = a		2004-06-21
		From Un eleve: (ln(50/x)) / (ln(40/x)) = a = constante comment extraire la variable x ??? Answered by Claude Tardif.
	How much loam to fill a hole?		2004-06-19
		From Harry: Can you tell me how much loam I would need to fill a hole 15 feet in dia. x 6 inches deep. Answered by Penny Nom.
	The surface area of a pyramid		2004-06-19
		From Jason: I was wondering how to find the area of a pyramid when you donít know the height of the face but the height of the Pyramids highest point? Answered by Penny Nom.
	Forty balls are placed in a bag		2004-06-19
		From Sheila: Forty balls numbered 1-10 are placed in a bag and four are drawn at random. What is the probability that the first ball drawn is between 1-10 (inclusive) the second is between 11-20, the third is between 21-30 and the last is between 31-40? Answered by Penny Nom.
	3+4i abd |3+4i|		2004-06-17
		From Sandy: how would you do a question like |3+4i|? is that different than just doing 3+4i? Answered by Penny Nom.
	An equation with rational terms		2004-06-17
		From Louise: simplify the expression (a2+n2)/2n = a2 + (a2-n2)/2n Answered by Penny Nom.
	Area of a lot		2004-06-17
		From Mike: Could you please figure out the square footage and acreage of my lot? One side is 228 feet, another is 150 feet, another is 80 feet, and the last side is 164 feet. My house is in the middle and it is 62 feet by 37 feet. Is that subtracted from the total? I would like to know this when I have to buy fertilizer. Answered by Penny Nom.
	A garden space		2004-06-16
		From Carol: We have a 17' x 19' garden space. If we want it a foot high raised bed, how many cubic yards of topsoil do we need? Answered by Penny Nom.
	The height of a building		2004-06-16
		From Lauren: I have a homework assignment to measure a building on my school's campus. I have to stand at least 40 ft away from the building and find the angle of elevation from my feet to the top of the building. Then I have to walk at least 40 ft form that point, record the distance as X, and find the angle of elevation from my feet to the top of the building. Using X and the angles, I have to determine the height of the building. I used a protractor and a weighted string to find the angle of elevation from my eyes to the top of the building. But I haven't been able to find the way to measure the angle of elevation from my feet to the top. Answered by Penny Nom.
	Solving an equation		2004-06-14
		From Anthony: I was hoping that you could help me with this problem. I believe that this is a high school level problem but as an adult who has forgotten the "rules", I am stuck. the equation is this: x=t2/(t1-t2) we know that x=5.73 t1=303 we must solve for t2 Answered by Penny Nom.
	The Number of the Beast		2004-06-13
		From A Heinlein reader: Most people who have an interest in mathmatics are familiar with Robert Heinlein's novel "The Number of the Beast", where 666, or ((6 to the 6th power) to the 6th power) equals 1.0315 times 10 to the 28th power, which in the novel is the number of parallel universes in the cosmos. My question is what would the number of parallel universes be if you grouped 666 the other way: (6 to the power of (6 to 6th power)). I have tried this on my calculator, but it won"t register that high. Answered by Penny Nom.
	Integers		2004-06-10
		From A parent: I have an odd 3 digit product. My factors are a 1-digit number and either or 2- or 3-digit number. My factors are odd, but neither is 1. Find my factors and my product. There is one answer. What is it? Answered by Penny Nom.
	Choosing an investment		2004-06-09
		From Max: Let's say I have a list of different possible investements, and the list shows me my cost, and how much each investment will sell for. In order to compare the investments and put them in order of relative profitability, I would want to sort them by their profits as percentages of what? Also, if each investment had an equal probability of losing exactly 10% of the sell price before I sold would that have any relevance to the way I would calculate it? Answered by Walter Whiteley.
	Jack's social security number		2004-06-08
		From A student: Jack's social security number contains each of the nonzero digits exactly once. By examining the digits from left to right, he also found that 1 divides the first digit evenly, 2 divides the sum of the first two digirs evenly, 3 divides the sum of the first three digits evenly, and so on, until 9 divides the sum of all the digits evenly. What is Jack's social security number? Answered by Penny Nom.
	The sum of some positive integers		2004-06-07
		From A student: Find the sum of all positive integers not greater than 10000 that are divisible by neither 3 nor 7. Answered by Penny Nom.
	What is the name of a 3D rectangle?		2004-06-07
		From Jack: if a cube is a 3D square, what is the name of a 3D rectangle? Answered by Penny Nom.
	The area of a pentagon		2004-06-06
		From Dana: HELLO, I NEED HELP IN DETERMINING THE SIZE OF A PENTAGON. one side is 280',from both ends of the 280 'section,we have 300' lengths,from one of these 300' sections we have a 118' length,which goes over to a length of 228',will this be enough info. or should i provide more. thanks Answered by Penny Nom.
	Percentage markup		2004-06-04
		From A parent: if our cost is 54.00 and their cost is 117.00 what is the percentage of mark up? Answered by Penny Nom.
	A tangent to a quadratic		2004-06-04
		From Jem: I have a question on the tangent to a quadratic curve. Say I have a curve y = ax2 + bx + c. The gradient, using the derivative of y, at any point x on the curve is: 2ax + b right? Then, for the tangent that cuts the curve at a point x, the equation of the tangent can be: y1 = (2ax + b)x1 + d. My question is, how is the point d of this tangent determined? It is the point on the y-axis where the tangent cuts isn't it? Is there a formula for it? Answered by Penny Nom.
	The game of 24		2004-06-04
		From Samantha: i have the game 24 (the one where you have to use multiplication, division, addition, and subtraction to get to the answer 24) I was playing when i came across the 4 numbers 20, 17, 7, 11 and i cant seem to get 24. Answered by Claude Tardif.
	Divisors of 2n+1 and 3n+9		2004-06-02
		From Chris: Amy selected a positive integer N and wrote numbers 2xN+1 and 3xN+9 on a whiteboard. Boris looked at the two numbers on the whiteboard and wrote in his notebook a positive integer that divides each of them. Find all possible numbers that Boris could have written in his notebook. Answered by Chris Fisher and Penny Nom.
	Cubic yards in a pool		2004-05-30
		From Jerry: HAVE A AREA WHERE I HAD A 18 FOOT ROUND POOL. THE DEEPEST PART IT WAS IN THE GROUND WAS AROUND 7 INCHES TAPERING DOWN TO AROUND 4 TO FIVE INCHES AND A LITTLE OF THE ONE SIDE ALMOST AT GROUND LEVEL...HOW MANY YARDS OF DIRT WOULD I NEED TO FILL IT IN???? IS THERE A FORMULA FOR THAT.......COULD YOU FIGURE THAT FOR ME? Answered by Penny Mon.
	The Parliament of the land of Achronia		2004-05-29
		From Christine: The Parliament of the land of Achronia consists of two houses. The parliament was elected in 2003 for a period of six years beginning on Thursday, the 1st of January 2004, when the two houses had their first sessions. According to the rules, the meetings of the first house must occur every twelve days for the duration of the term, and the meetings of the second house must occur every eighteen days. For example, the second meetings of the first and the second houses were held on the 13th and 19th of January respectively. A new law can be passed on any day when both houses meet, except on a Thursday. On how many days can the parliament members pass new laws during this six year term? Answered by Penny Nom.
	112!		2004-05-28
		From Beatriz: 1) A bus driver collects identical sets of 5 coins from each passenger. If the totoal colledted was $21.83, how many pennies did the driver get?? 2) How many terminal zero in the base 10 expression of 112! (factional) N! means N(N-1)(N-2) .....(2) (1). Answered by Penny Nom.
	Different infinities		2004-05-27
		From Plober: How can I explain to a friend (in a bar, using as a pen and a paper napkin) that the integer's infinity is 'smaller' than the irrationals's one? The demo I tried was that you couldn't match the integers with the real numbers between 0 and 1 (that 0.xxxxx replacing the Nth number from a different one... that demo), but she used my argument >:| saying that you can add one to the integer's infinite, and the number I was creating was only one more... I can't think of any other way, and I KNOW the real's cardinality is greater than the integer's one Answered by Claude Tardif and Penny Nom.
	English		2004-05-27
		From Chang: well my question is i was told by most of the teachers that ''think in english'' is the best way to learn english but how can i do like that do i need to know about the stucture first or do i need to learn the western culture ? here is a sentence i have translate directly from my mother language.'' i was given an admiration of sincerity from this client on the follow up action i have done in the complaint. Answered by Claude Tardif.
	The horizontal fraction bar		2004-05-27
		From Kashia: What is the name of the bar that separates a numerator and that denominator? Answered by Penny Nom.
	The center of a circle		2004-05-26
		From Wan: I am trying to find the radius of an arc. The only things i know about the arc is all referenced from the line of tangency to the arc. on both sides i have a differnt horizontal perpendicular distance to the point of tangency. left side |-------*---------------| right side (*=point of tangency). Then i have 2 difference vertical perpendicular distance of the end points to the line of tangency. I know it sounds very bad in text but this is all i know about the arc. Can you help me find the radius? Answered by Penny Nom.
	The base of a triangle		2004-05-25
		From Ralph: With a 30 degree angle at the top of a triangle and a height of 15 what is the base? Answered by Penny Nom.
	Programming without trig functions		2004-05-25
		From Derek: I am a programmer trying to calculate the following. What is the formula to find the cross-sectional area of a cylinder with out using any trig functions? or better yet, how can you calculate any given volume in a cylindrical tank with spherical heads with out trig functions? I am using a PLC (programmable logic controller) to do this and trig functions are not available. Answered by Harley Weston.
	Finding bearings		2004-05-24
		From James: This question is about finding bearings. A boat race starts from point A, goes North to Point B, a distance of 1000 meters. The course is triangular. The bearing from point B to point C is South 70degrees West. The distance from Point B to point C is 1500 meters. Find the course bearing from C to A. Answered by Penny Nom.
	Some trig expressions		2004-05-23
		From A student: Prove: sin A + sin B = 2sin(A+B/2)cos(A-B/2) cos A - cos B = -2sin(A+B/2)sin(A-B/2) cos A + cos B = 2cos(A+B/2)cos(A-B/2) sin A - sin B = 2cos(A+B/2)sin(A+B/2) Answered by Penny Nom.
	Volume of a box		2004-05-23
		From A student: The area of the top of a closed rectangular box is 252cm2, the area of the front of the box is 105cm2, and the surface of the box is 834in2 (or 5380.64cm2). What is the volume of the box? Answered by Penny Nom.
	How far apart are they?		2004-05-23
		From A student: 2 cars start at same loc. drive opposite direction for 6 miles then they each turn left and travel for 8 miles how far apart are they? Answered by Penny Nom.
	33 3/4 doubled		2004-05-22
		From A tailor: need to know how to add 33 3/4 doubled. How do I come up with the solution? I need to know for measuring garments. Usually I measure on the half meaning on the front of the garment and then double it with the measuring tape but I always get stuck when I need to measure 3/4 such as 66 3/4 doubled and etc. Can you help me figure this out easily. Answered by Penny Nom.
	The perimeter of a triangle		2004-05-21
		From A student: In a triangle i have the length of a line and it's opposite angle.how can i calculate perimeter?(the angles are not right) Answered by Penny Nom.
	Frieze patterns		2004-05-19
		From Christina: How can I prove that there are only seven unique geometric frieze patterns? Answered by Penny Nom.
	Word problems		2004-05-19
		From A student: why can't 2nd graders have a easy time doing word problems and drawing pictures with it Answered by Diane Hanson.
	The dimsenions of a room		2004-05-18
		From Estella: I have a room that is rectangular the area is 159.5 feet, the perimeter is 51 feet what would the dimensions of the room. Answered by Penny Nom.
	Angles of elevation and depression		2004-05-18
		From Anjum: what is the difference between an angle of elevation and angle of depression? Answered by Penny Nom.
	The combinatiion for a keybox		2004-05-17
		From Darrin: I have a puzzle question based on reality. I have a real-estate type keybox (Supra) that has 10 digits, 0-9. I am trying to figure out a methodical way to test all number combinations to it to open it. (totally legal- it was taken from the trash at a jobsite since they couldn't open it!) The combination could be any or all of the digits, but any digit is only used once. This is not like a simplex lock problem where a combination of keypresses would be different- i.e. 1,2,3 is the same as 1+2,3. Any ideas? Answered by Penny Nom.
	Diagonals in a regular dodecahedron		2004-05-15
		From Joshua: A dodecahedron has twelve faces, all of which are regular pentagons. Three edges meet at each vertex of the dodecahedron. An interior diagonal is a segment connecting two vertices such that the segment is not an edge or along a face of the dodecagedron. How many interior diagonals does a regular dodecahedron have? Answered by Penny Nom.
	Maximizing the angle to the goal mouth		2004-05-15
		From Yogendra: You are running down the boundary line dribbling the ball in soccer or hockey. Investigate where in your run the angle the goal mouth makes with your position is at a maximum. Answered by Penny Nom.
	Mrs. Smith's class		2004-05-12
		From Amanda: Mrs. Smith's class has 35 student. Today there are 2/3 of them absent. How many are absent? present? Answered by Penny Nom.
	Subtracting fractions		2004-05-11
		From Filipe: Question: _5_ - __7__ 6ab 8a Answered by Penny Nom.
	Area of a lot		2004-05-11
		From Dana: HELLO MY NAME IS DANA ,I AM AN AVERAGE JOE WITH A QUESTION THAT I CANNOT ANSWER MYSELF SO I CAME TO YOU, I HAVE A PIECE OF PROPERTY IN THE SHAPE OF AN ISOSCELES TRAPEZOID THAT IS 250 FEET ACROSS THE BACK, 100 FEET ACROSS THE FRONT AND BOTH SIDES ARE 600 FEET LONG. HOW MANY SQUARE FEET ARE IN THIS PROPERTY.? Answered by Penny Nom.
	A pyramid		2004-05-11
		From Quiana: I am a student and I have the following questions I need to answer for homework: How many sides, vertices, and edges does a pyramid have? Answered by Penny Nom.
	Three dice		2004-05-10
		From A student: If one has 3, 6 sided dice what is the probability of the numbers that are rolled to total 4 through 10 inclusively? Subsequent to this, what is the probability to do this consecutively...say 3 times? Answered by Peny Nom.
	Pi		2004-05-10
		From Kim: I'm a 7th grader at Lakeside Middle School. And I was wondering if you can answer a question for me for my math project. I'm doing a project on pi, and my teacher said to ask an expert like you to ask about how you would use the subject, pi, in real life usage. How would you use pi in real life usage? Answered by Penny Nom.
	Why the word combinations?		2004-05-05
		From Megan: Why are locker combinations called locker combinations not locker permutations. The order of the numbers matter so why aren't they called locker permutations. Answered by Claude Tardif and Penny Nom.
	Chi-Squared		2004-05-05
		From Gillian: OF75 PEOPLE, 43 ARE EXPOSED TO A VIRUS AND BECOME ILL. 11 PEOPLE ARE EXPOSED AND DO NOT BECOME ILL. 3 PEOPLE ARE NOT EXPOSED AND BECOME ILL. 18 PEOPLE ARE NOT EXPOSED AND DO NOT BECOME ILL. THE ATTACK RATE IS 80% FOR THOSE EXPOSED AND 14% FOR THOSE NOT EXPOSED. THE RELATIVE RISK IS 5.7. CAN YOU EXPLAIN TO ME HOW TO CALCULATE A CHI SQUARE TEST FROM THIS. Answered by Penny Nom.
	3x squared - 27 / x + 3		2004-05-04
		From Stef: 3x squared - 27 / x + 3 Answered by Penny Nom.
	A 3 digit number divisible by 7		2004-05-03
		From A student: We need to arrange 1,3 and 6 to form a 3 digit number that is divisible by 7. Answered by Penny Nom.
	Solving inequalities		2004-05-03
		From Joe: Let x be a real number find and graph the solution to the following sentances: 2x-10+9 4X+2<15 5X+3>(x-1) Answered by Peny Nom.
	A clock chimes 7 times in 7seconds		2004-05-02
		From Anna: A clock chimes 7 times in 7seconds. how long does it take the clock to chime 10 times? Answered by Penny Nom.
	The equation of a line		2004-04-30
		From Amy: Write the equation of the line that contains the point (-4,6) and is perpendicular to the line y=5x+100. Answered by Penny Nom.
	Setting up an equation		2004-04-30
		From Matt: I am trying to determine the dimensions of a 22 megapixel digital camera chip that has a 3:2 ratio. We know then, that: 3x = 2y (or 1.5x = y) and that xy = 22 Beyond this, I don't know how to hook those 2 seemingly unrelated facts together. Answered by Penny Nom.
	The sum of 4,0,-4..., -156		2004-04-28
		From Christina: find the requested sum of the arithmetic sequence 4,0,-4..., -156 Answered by Penny Nom.
	Yards in a concrete driveway		2004-04-27
		From Bobbi: I am wondering how many yards of cement I need for a 49 by 45 area, 5 inches thick. I am a stay at home mom who is not very good at math and I want to pave my drive way. Also what would the yardage be for a 6 inch thick drive way with the same area. Answered by Penny Nom.
	Factoring		2004-04-27
		From Bipin: FACTORISE: a to the power of 6 + b to the power of 6 Answered by Penny Nom.
	An oil-drilling platform		2004-04-27
		From Alie: An oil-drilling platform is located in the Gulf of Mexico 3.25 miles from the nearest point on shore. From a point B on the shore due east of A the bearing of the platform is S51.2W. How far is it from B to the platform? Answered by Penny Nom.
	The height of a triangle		2004-04-27
		From Danielle: what is the definition of height of a triangle? Answered by Penny Nom.
	Related rates and baseball		2004-04-26
		From Bethany: A baseball diamond is the shape of a square with sides 90 feet long. A player running from second to third base at a speed of 28 feet/ second is 30 feet from second base. At what rate is the player's distance from home plate changing? Answered by Penny Nom.
	The problem of Apollonius		2004-04-25
		From Mitja: There are given 2 circles lying one out of another and one point out of both circles. How to construct a circle passing through a given point and internally tangent to one and externally tangent to the other cirlce? Answered by Chris Fisher.
	A Fibonacci triangle		2004-04-25
		From Marcelle: Is it possible to construct a triangle with sides that are three consecutive Fibonacci numbers? Answered by Walter Whiteley.
	Water in a pipe		2004-04-25
		From Marlean: How much water would be in a 480 foot one inch inside diameter pipe?? In imperial gallons please. thanking you in advance for your help in this matter. Answered by Penny Nom.
	Place Value		2004-04-25
		From Santosh: Q. Write the Place value of the digits in the following numerals. 1. 5 in 54 2. 3 in 63 Answered by Penny Nom.
	Marching legion		2004-04-24
		From Art: A column of soldiers is 100 meters long. Their sargeant at the rear of the column gives the order to march. The sargeant marches alongside the column to its head and then back to the rear, at which point he gives the order to halt. In all, the column of soldiers has marched 100 meters. How far has the sargeant marched? I say 187.5 meters, but those who teach or who have taught mathematics tell me no. Some say much more and some different. What do you say? Answered by Penny Nom.
	Three parabolas		2004-04-24
		From A tutor: I am a maths tutor. One of my year 12 students has given me this assignment. Many parts are ambiguous. I am trying to determine the equation of the line segment AB. Given that A has an incline of 10 degrees below the horizontal, I am assuming that this parabola (although you can only see part of it) has been rotated 10 degree clockwise. Am I right in assuming this? If so, how do I derive the equation of the parabola as it will then not fit the general form y = ax squared +bx +c of a parabola. Also, how is one expected to find the x coordinate of D without the equation of this parabola. To find the equation you need the x-coordinate and therefore be able to find another point on the parabola in order to derive the equation using simultaneous equations. Answered by Penny Nom.
	Arrays		2004-04-23
		From Jan: 4x7 = 28 How many arrays can this have? How do you determine the arrays??? Answered by Penny Nom.
	square root 125 x 16		2004-04-23
		From Mike: how do you simplify a square root of "- square root 125 x16" when x is a variable... i don't really get how to do this.... Answered by Penny Nom.
	The "22" puzzle and the "1089" puzzle		2004-04-22
		From Marcelle: 1. Choose 3 digits from 1-9 2. Make all the 2 digit numbers you can from these (6) 3. Add the 3 original digits and divide them into the sum from step 2. The answer is always '22'. I just can't understand why. Can you please help. Another one related to this is it: 1. Choose a three digit number ensuring the first and third digit are differnt by at least two. 2. Make the reverse three digit number and subtract the smaller one from the larger of these. 3. Take this answer and reverse it and add these two 3 digit numbers . eg: 643 - 346 = 297 297 + 792 = 1089 it doesn't matter what numbers are used, the results are alwasy the same. eg 22 or 1089 Answered by Paul Betts.
	Why is ounces abbreviated oz?		2004-04-22
		From Someone curious: Why is ounces abbreviated oz? Answered by Chris Fisher.
	What's it called?		2004-04-22
		From Gerry: I'm a father and a grandfather and have come up with a game for my offspring to play while we're on the road. When we see a license plate, the object is to be the first one to add all the numbers on it, and come up with THE one digit number that sums them up. For example: ABC-787 = 7+8+7 = 22 = 2+2 = 4 Another example is 2932 = 2+9+3+2 = 16 = 1+6 = 7 Up 'til now, I've called it just plain "Numerology", but I'm sure that there's a math term for what we're doing, and I'd sure appreciate it if you could tell me what it is! Answered by Chris Fisher and Penny Nom.
	Surface area of a cylinder		2004-04-17
		From Kathryn: How do you find the radius of a cylinder when you are given only the surface area and the height of the cylinder? Answered by Penny Nom.
	The line through (4,2) and (4,-8)		2004-04-17
		From Kim: Write an equation for the line. Given points (4, -8) and (4,2) are on the line. I believe m=undefined. How do I solve for b when m is undefined, and then plug in the values for m, b, and y? Answered by Penny Nom.
	Some factoring problems		2004-04-15
		From KJ: Factor these: x3+125 -----> (x+5)3 8x3-27 -----> (?) x2+36 -----> (x+6)2 x4-5x2+4 --> (?) Answered by Penny Nom.
	A probability density function		2004-04-14
		From A student: The label on a bottle of liquid detergent shows contents to be 12 ounces per bottle. The production operation fills the bottle uniformly according to the following probability density function: f(x) = 8 for 11.975 <= x <= 12.10 and f(x) = 0 elsewhere a. What is the probability that a bottle will be filled with 12.02 or more ounces? b. What is the probability that a bottle will be filled between 12 and 12.05 ounces? c. Quality control accepts production that is within .002 ounces of number of ounces shown on the container label. What is the probability that a bottle of this liquid detergent will fail to meet the quality control standard? Answered by Penny Nom.
	A geometric sequence		2004-04-13
		From Michael: In a geometric series, the sum of the 2nd and 3rd terms is 60, and the sum of the 3rd and 4th terms is 240. Find the sum of the first 7 terms. Answered by Penny Nom.
	Circles in a hexagon		2004-04-11
		From Crystal: step by step can you show me how to calculate the area of the region inside the hexagon but outside the seven circles. given the radius of each circle is one inch Answered by Penny Nom.
	Percent difference		2004-04-10
		From A parent: For a school science project, my son Alex is taking measurements of plant growth at regular intervals. As part of the data, he must provide the maximum percent difference observed in the categories his team has identified. So, for example he has six plants with four measurements each. (He has more, but I'll keep it simple) For the first plant he measured 2mm, 2.4mm, 2.9mm, and 3.2mm. For the 2nd, 3rd, and 4th plants, he has similar numbers. Is there a way to calculate the maximum percent difference between any two plants in his measurements during the project? Doing it for each combination would be tedious. Answered by Penny Nom.
	Snow in the driveway		2004-04-09
		From Patricia: Following a severe snowstorm, Ken and Bettina Reeves must clear their driveway and sidewalk. Ken can clear the snow by himself in 4 hours, and Bettina can clear the snow by herself in 6 hours. After Bettina has been working for 3 hours, Ken is able to join her. How much longer will it take them working together to remove the rest of the snow? Answered by Penny Nom.
	What is the nth term		2004-04-07
		From Jason: 1 4 10 20 35 56 84 what is the nth term Answered by Claude Tardif.
	Rational expressions		2004-04-06
		From Shivani: I am in 11th grade Honors Algebra II. We are currently learning about adding and subtracting rational expressions. I looked at the other questions that were similar to that of mine, but they weren't quite answering my question. I have been working on many problems to practice and see if I can come up with the correct answer, but I can't, I got like 2 out of every 7 right on my school homework. I get the easy ones, where when you have to find the LCD, it's just the other denominator. But, on others you have to really think about it. Those are hard. Here are some of the problems that I cannot get at all: (x2 - 3x + 1)/(x2 - 4) - (x2 + 2x +4)/(2 - x) - (x - 4) /(x - 2) The correct answer is: (x3 + 4x2 + 7x + 17)/(x2 - 4) Answered by Penny Nom.
	The sum of angles in a triangle		2004-04-06
		From A student: How can u prove sum of angles in a triangle equal to 180 degrees? Answered by Penny Nom.
	Differences in percentages		2004-04-06
		From Jose: Question: You have two groups: Group A has 10 people and 2 are Chinese Group B has 12 people and 3 are Chinese In terms of percentages what is the difference in Chinese between the two groups? In other words which group has the biggest percentage of Chinese and why? Answered by Penny Nom.
	Trisecting an arbitrary angle		2004-04-06
		From Joe: Where can I submit my effort on trisecting an arbitrary angle with only a straightedge and a compass? I can do it but I do not have the smarts to prove it.S Answered by Chris Fisher.
	Ratios		2004-04-05
		From Tim: The ratio of W to H was 7 to 9. The ratio of H to I was 9 to 5. If the sum of the W and H exceeded twice the number of I by 12, how many were W, how were H and how many were I? Answered by Penny Nom.
	x^2/3 - 7 x^1/3 + 12 = 0		2004-04-05
		From Jackie: I am having trouble solving this question for x: 1.) x^2/3 - 7 x^1/3 + 12 = 0 Answered by Penny Nom.
	(3x50)+20/5=?		2004-04-03
		From A student: what is the answer to: (3x50)+20/5=? Answered by Penny Nom.
	A changing rectangle		2004-04-03
		From A student: The width x of a rectangle is decreasing at 3 cm/s, and its length y is increasing at 5 cm/s. At what rate is its area A changing when x=10 and y=15? Answered by Penny Nom.
	Ratio and proportion		2004-04-02
		From Kenneth: The terms of a ratio in a proportion are often expressed as a is to b as c is to d. Example: 2/4 = 6/12 this proportion represents that 2 is to 4 as 6 is to 12. What does the "a is to b as c is to d" really represent or indicate in ratios? Answered by Claude Tardif.
	Some calculus problems		2004-04-01
		From Weisu: I have questions about three word problems and one regular problem, all dealing with derivatives. Find all points on xy=exy where the tangent line is horizontal. The width x of a rectangle is decreasing at 3 cm/s, and its length y is increasing at 5 cm/s. At what rate is its area A changing when x=10 and y=15? A car and a truck leave the same intersection, the truck heading north at 60 mph and the car heading west at 55 mph. At what rate is the distance between the car and the truck changing when the car and the truck are 30 miles and 40 miles from the intersection, respectively? The production P of a company satisfies the equation P=x2 + 0.1xy + y2, where x and y are the inputs. At a certain period x=10 units and y=8 units. Estimate the change in y that should be made to set up a decrease of 0.5 in the input x so that the production remains the same. If you could just give me some hints on these questions, I'd really appreciate it. Thanks! Answered by Penny Nom.
	The intersection of two graphs		2004-03-31
		From Benjanim: How do I find the points of intersection of the two functions: 1) y = 2 - (e^-x) 2) y = 1 + (x^2) I know that I have to set them equal to each other, but I can't solve for x. Please help :-) Answered by Penny Nom.
	Algebraic simplification		2004-03-31
		From Chris: Simplifying Exponents Question b^5d^2/b^3d^8 Answered by Penny Nom.
	The degree sequence of a graph		2004-03-31
		From Ali: How can i find out {6,6,5,5,5,3,2}is not the sequence of the points of a simple graph,without drawing it? Answered by Penny Nom.
	Replacement times for TV sets?		2004-03-31
		From Barb: Replacement times for TV sets are normally distributed with a mean of 8.2 years and a standard deviation of 1.1 years. Estimate the probability that for 250 randomly selected TV sets, at least 15 of them have replacement times greater than 10.0 years.e Answered by Andrei Volodin and Penny Nom.
	A derivative		2004-03-31
		From A student: What is the nth derivative of f(x) =(2x)/(1-(x2))? Answered by Harley Weston.
	The height of a building		2004-03-31
		From Nat: Two buildings are 26.3m apart. From the top of the shorter building the angle of elevation to the top of the taller building is 35.9 degrees and the angle of depression to the base of the taller building is 54.7 degrees. What is the height of the taller building? Answered by Penny Nom.
	425 cc's of a saline solution		2004-03-30
		From Julie: 425 cc's of a saline solution is equal to how much in lbs-weight?? Answered by Harley Weston.
	n! > n^2		2004-03-30
		From Jose: How can you prove by mathematical induction that: n! > n2. Answered by Penny Nom.
	A stained glass window		2004-03-29
		From Kay: I'm doing a stain glass project and it's on a 4 foot across octagonal window...and I'm trying to set up the pattern and I don't know how long the sides are! Answered by Penny Nom.
	Numbers around a circle		2004-03-28
		From Rebecca: my maths question is use the numbers 1,2,3,4,5,6 and 7 place each number in a circle so each line adds up to 12. There are seven circles, six on the outside and one in the middle. Each number lines up with the middle number and the outside numbers line up with the one directly across from it as if a line was going through the middle number circle. Answered by Penny Nom.
	Percentage difference		2004-03-28
		From Someone: what is the percentage difference between 157 to 251 Answered by Penny Nom.
	Maximizing the area		2004-03-27
		From Petey: Please could you tell me why for my coursework (where I have to find the largest area that a fence 1000m long can cover) why I should only test equilateral and isoceles triangles? We were told NOT to do right angled triangles but I was wondering why not? Answered by Penny Nom.
	The volume of a sphere		2004-03-26
		From Mike: I was in class today and I learned how to calculate the volume of a sphere. I understood it easily but can't find the logic behind it. So here are my questions, in the formula why is the radius cubic and not squared? And what does 4/3 have to do with it? Answered by Penny Nom.
	z^2 = 3 - 4i		2004-03-26
		From John: Solve: Z^2 = 3 - 4i Answered by Harley Weston.
	Large exponents		2004-03-26
		From John: I have encountered problem with the lack of memory every calculator seems to have. No calculator, on or off the computer, I've found has the amount of memory or writing space to calculate the sums I want to solve. The sums are in great importance for my continued progress. The sums are following: 16777216^1310270, 16777215^995328, 16777215^786432 and 16777215^480000 Answered by Claude Tardif.
	Sections, area and acres		2004-03-23
		From Tony: An acre , it can be any size right . so when they refer to a section of a township which is 640 acres, also 1 square mile does this mean that 1 sections length if sqaure and there is 5,280 ft in 1 mile does it meanthat if you took 1 side of the square of of 4 sides the lenth would be 5,280 feet long and by multiplying 5,280 x 5,280 it would give you the square mile in square feet. i guess what I 'm asking is what is the perimeter of 1 acre if it was shape like a square. sorry to make this confusing but if you can help I would appreciate it. Answered by Penny Nom.
	Four marbles on a box		2004-03-22
		From Karyn: Suppose 2 solid color marbles and 2 striped marbles are placed in a box. All are the same size. If one marble is randomly drawn from the box and replaced, then a second marble is randomly drawn, what is the probability that the marble drawn both times will be striped? I know there is a simple formula for working this out but I can't remember how. Answered by Penny Nom.
	What's the next term?		2004-03-22
		From Garrett: A friend hit me with these questions and won't tell me the answer nor how... please help? I've racked my brain and did all sorts of formulas, but I can't get it to work out... please... What's the next number in this series... 5, 12, 17, 29, 46, ? And this series... 12, 19, 28, 39, 52, 67, ? and these... ocoa, boco, oboc, dobo, odob, ? Answered by Claude Tardif.
	BEDMAS		2004-03-20
		From Brad: I am in grade 7. My teacher tells me brackets always first, well i know that but, 5 (-4) x 2 Does the (-4) count as a bracket or is it just telling you not to minus 4 from 5 but to multiply 5 x -4 ? Am i correct? Answered by Penny Nom.
	A partial derivative		2004-03-19
		From Penny Nom: Is it possible to differentiate the following equation, if so could you please explain. S=SQRT(T-(5/X^2)) I would like the derivative of S with respect to X. Answered by Harley Weston.
	A fraction of a fraction as a percent		2004-03-18
		From Mary: I would like to know if you could help me with this problem? Could you take me though the steps to this math problems. 3 =(?)% x 3 --- --- 16 4 the question states: Finding what is the percentage of a fractional number and another fractional number. Answered by Penny Nom.
	A water lily		2004-03-17
		From Inba: A water lily with a rigid stem extends one foot above the surface of the water. When pulled over, it disappears beneath the water at a distance 3 feet from where the stem originally entered the water. How deep is the pond? Answered by Penny Nom.
	Factoring x^2 + 5x + 4		2004-03-14
		From Keenan: how do I factor x^+5X+4? Answered by Penny Nom.
	Johann Muller		2004-03-14
		From A student: What major contributions to spherical trigonometry did Johann Muller make? Answered by Penny Nom.
	Baseball games		2004-03-14
		From Fabian: Let's say I have 12 different Baseball games. There is one of only 2 possible outcomes for each of the 12 games. How would I fugure out how many combinations there are for the 12 games and for 11,10, and so fourth. Answered by Penny Nom.
	A new baby		2004-03-14
		From Jessica: I just had a baby 3weeks ago, he is in the hospital and he can come home when he is 1800 grams, well i was wondering how many pounds that is? Answered by Penny Nom.
	Some ratio problems		2004-03-13
		From Hossen: 1) After James spent 2/5 of his pocket money on magazines, and 1/4 of his pocket money at a football match, he had £1.75 left. How much pcket money did he have in the beginning? 2) A joint of Lamb costs £5.95 per/kg. The price per kilogram is reduced. A joint weighing 1.2kg is reduced by 50p. A) What is the reduced price per kilogram? c Answered by Penny Nom.
	Billions in Australia		2004-03-12
		From An Australian: how many million in one billion ? Answered by Penny Nom.
	Area and perimeter		2004-03-12
		From Sandy: The rectange has an area of M square units and a perimeter of 2M units. What is the value of x? The length of the rectange is 3, while the width of the rectange is x-1. Answered by Penny Nom.
	Sum of the angles in a pentagon		2004-03-11
		From Ashish: What is the sum of all the measures of the angles of a Pentagon Answered by Penny Nom.
	Distance, time and rate		2004-03-09
		From Peter: A car travels from one city to another at the speed of 32mph, if it had gone 4mph faster it could have made the trip in one half hour less. How far apart are the cities? Answered by Penny Nom.
	The area of a lot		2004-03-09
		From Dave: If our lot is 192.71 x 138.79 x 158.74 x 103.08 Question is what percentage of an acre is our lot? Answered by Penny Nom.
	The factor theorem		2004-03-08
		From LisaMarie: Hi, I have a career link question from gr.12 advanced functions and intro. calculus. The equations is: R(t) = 5(t4 - 4t3 + 19/4 t2 - 3/2 t) The question is to apply the factor theorem and quadratic formula to determine the times it crosses the t axis. The only method i know of for using the factor theorem is when the last number does not have a variable beside it so i'm not sure how you would even use the factor theorem for this? We haven't dealt with any that have 0 as the last number with no variable so i'm a little confused! please help! Thank you Answered by Penny Nom.
	A metric prefix table		2004-03-07
		From April: Can you tell me what the scale is for nano, micro, mega, kilo, etc.... I know that mega is 10 to the sixth power but I can't remember the other ones. Answered by Penny Nom.
	Equivalent sets		2004-03-06
		From A student: If A=(1,2,3,4,...) and B=(5,10,15,20,...), is A equivalent to B. Why or Why not ? Answered by Penny Nom.
	The radius of a circle		2004-03-06
		From A student: what is the radius of a circle with the circumference of 12 inches? Answered by Penny Nom.
	The units digit of 4^478		2004-03-06
		From Elizabeth: What is the units digit of 4478? Answered by Penny Nom.
	A fifteen sided polygon		2004-03-05
		From Joann: WHAT IS THE NAME OF A FIFTEEN SIDED SHAPE? Answered by Penny Nom.
	A geometry problem		2004-03-04
		From Jennifer: I need help with this problem: Square ABCD has side length 2. A semicircle with diameter AB is constructed inside the square, and the tangent to the semicircle from C intersects side AD at E. What is the exact length of CE?o Answered by Chris Fisher.
	Cosine of 35 degrees		2004-03-03
		From Jason: How do you find the exact solution to cosine 35 degrees. Answered by Chris Fisher.
	Proof by induction		2004-03-02
		From Chris: I need some help of how to solve the problem "use the principle of mathematical induction to prove that the following are true for all positive integers" cos(n x pi + X) = (-1)^n cosX any help would be appreciated Answered by Penny Nom.
	Volume of a fuel tank		2004-03-01
		From Mike: I have a fuel ank for my big truck that has a radius of 24inches and a length of 65 inches. I am trying to compute the volume of fuel in the tank. I tried pie x the radius squared times the length but no usable results. Can you help me please? Answered by Penny Nom.
	Billions and more! and even more!		2004-03-01
		From Steph: What comes after undecillion? Answered by Penny Nom.
	Even-numbered roots		2004-03-01
		From A student: I understand that the square root is defined to be positive only. Does the same rule apply to other even-numbered roots, such as the 4th root, or the 6th root, etc.? Answered by Harley Weston.
	Logs		2004-02-29
		From Sandy: find X 3/2logb4-1/2logb8+logb2=logbx my book uses prop 7 to rewrite as logb4raised3/2-logb8raised2/3+logb2=logbx; then writes logb8-logb4+logb2=logbx how did it get here? Answered by Claude Tardif.
	A dress-maker's pattern		2004-02-27
		From A dress-maker: Does a dress-maker's pattern for a dress, such as a skirt made up of several pieces of isosceles trapezoid, qualify as a net? How about patterns for other types of clothing or accessories e.g. jackets, handbags?Î Answered by Diane Hanson.
	Napoleon's theorem		2004-02-27
		From David: How do i prove this : For any triangle, if you make 3 equillateral triangles using the sides of the the original triangle, the central points of the 3 tringles another triangle that is equillateral.z Answered by Chris Fisher and Penny Nom.
	GST and PST		2004-02-26
		From Mallory: I was absent on the day that my teacher taught the class how to find the GST and PST of items. I sort of understand that GST is 7% and PST is 7.5%, but our teacher said that we shouldn't combine the two to find the total amount... I'm really confused, so can you please help me?& Answered by Claude Tardif.
	Three jugs		2004-02-26
		From Shelly: You have three jugs: A 6 Liter, 4 Liter and a 3 Liter. Your goal is to get exactly 5 Liters of liquid in the 6 Liter jug. Your supply of liquid is unlimited and there are NO markings on the containers. You cannot do halves. Answered by Claude Tardif.
	The point where all the medians meet		2004-02-25
		From A student: What's the name of the point where all the medians meet? Answered by Penny Nom.
	Rearranging an expression		2004-02-24
		From Corey: use the following formula to answer the question F=9c divided by 5 plus 32 rearange the formula to solve for c how many degrees fahrenheit would it be it it was: 0 degrees celcius -10 degrees celcius -46 degrees celcius Answered by Penny Nom.
	An elliptic cone		2004-02-24
		From Ben: I am building a model for my architecture class. I need to build a elliptic cone out of chipboard and i have no idea how to do this. The cone needs to be 20in tall and the ellipse has a max radius of 10in and a min radius of 8in. So my question is how do i lay this out on a piece of paper so that i can form the cone after i cut it out. Answered by Penny Nom.
	Profit, markup and discount		2004-02-22
		From Kick: Using the calculation on your website, if I sell something for $885 and my cost is $296, I make $589 profit. How do I calculate the profit percent I made on that transaction? Profit as a percentage of what it cost me? Profit as a percentage of what I sold it for? Answered by Penny Nom.
	A problem with logs		2004-02-22
		From Caitlyn: problem: ln x + ln (x-2) = 1 I can solve this on the calculator, but the book wants 1+ [(sqroot)1+e]. How can I get the e? Answered by Penny Nom.
	Selecting balls from a golf bag		2004-02-21
		From A student: There are 5 white and 5 yellow balls in a golf bag. Two are selected randomly, and simultaneously. What is the probability that the first one or the second one will be white? Answered by Penny Nom.
	The dimensions of a rectangle		2004-02-21
		From Jane: A rectangular label has an area of 176cm2 and a perimeter of 54cm. Find the dimensions of the label. Answered by Penny Nom.
	Gallons in a cylinder		2004-02-20
		From Jim: Please advise how to use the formula I saw for determining the number of gallons in a cylinder? This is how it was written V = pi r2 h . does this mean pie, or 3.14 X radius squared, X the height? If so please use a standard 55 gal barrel (1' R & 3' H) for example? Answered by Penny Nom.
	Arrays		2004-02-19
		From A parent: please demonstrate mathematical arrays fro a 3rd grader Answered by Penny Nom.
	A worm crawling home		2004-02-18
		From Cindy: A worm is crawling to his home which is one meter away. The longer he crawls the weaker he gets and the less he can crawl the next day. If he crawls within 1/3000 of a meter of his home, he will find food. He must eat within twelve days. The first day he crawls 1/2 meter. The second day he crawls 1/4 meter. The third day he crawls 1/8 of meter. This pattern continues for twelve days. Make a Chart that shows the distance he has covered at the end of each day and the total he has covered at the end of each day. Does he make it to the Food in time? Answered by Penny Nom.
	Nonconvex shapes		2004-02-18
		From Merrill: Draw 4, 6 and 8 sided shapes so that ONE straight line can be drawn through each side Answered by Chris Fisher and Penny Nom.
	Acres and square miles		2004-02-17
		From Richard: How many acres are in .17 square miles? and How many acres are in .6 square miles? The two areas I am requesting information about are Vatican City and San Marino, the two smallest countries in the world. If I can transfer the sq. miles into acres , I can relate the size of these countries to our school grounds and the students will better understand their sizes. Answered by Penny Nom.
	Grams and Milliliters		2004-02-17
		From Chantal: We have to do a "thing", and I need to convert grams into mililitres (g into mL). how can I do this? Answered by Penny Nom.
	Areas, perimeters and derivatives		2004-02-15
		From Geoff: A recent lecture in my calculus class led me to realize that the derivative of the area of a circle, with respect to the radius is equal to the circumfrence. This also holds true for the relationship between the volume of a sphere and the surface area of that sphere: why do these hold true? why is it only for circular objects? Answered by Harley Weston.
	An arc on a train track		2004-02-15
		From A student: I'm trying to build a route in a train simulator program. I have a curve to the right (an arc, in other words) with a length of 25 meters and the radius is 1,500 meters. Let's say point P is the beginning of the curve (arc) and point Q is the end point of the arc. Then picture a tangent to point P. I need to find the length of a line perpendicular to that tangent that runs to point Q (the end of the curve/arc). Answered by Penny Nom.
	The derivative of x to the x		2004-02-14
		From Cher: what about the derivative of x to the power x? Answered by Penny Nom.
	The substitution method		2004-02-14
		From Keisha: I need to solve this problem by using the substitution method. 3x+y=1 x=2y+5 Please help me understand the method to solve. Answered by Penny Nom.
	Probabilities and olivies		2004-02-14
		From Annetta: A bowl contains five green olives and eight black ones. Wilma sticks a fork into a bowl and brings out two olives. What is the probability that she gets one green and one black olive? Answered by Harley Weston.
	Red riding hood		2004-02-14
		From Frank: Red riding hood had a number of jars to take to grandma's house. As she traveled she gave away 1/3 of them to an old lady. Then later As she walked through the forest a wolf stole 1/2 of her remaining jars. When she arrived at grandma's house she gave her 2/3 of the remaining jars. She kept 6 jars for herself. How many jars did she start out with. Answered by Diane Hanson.
	A pyramid-shaped tank		2004-02-13
		From Annette: The base of a pyramid-shaped tank is a square with sides of length 9 feet, and the vertex of the pyramid is 12 feet above the base. The tank is filled to a depth of 4 feet, and water is flowing into the tank at a rate of 3 cubic feet per second. Find the rate of change of the depth of water in the tank. (Hint: the volume of a pyramid is V = 1/3 B h , where B is the base area and h is the height of the pyramid.) Answered by Harley Weston.
	Fractions		2004-02-13
		From A parent: 12/36=?/18=4/?=?/9 Answered by Penny Nom.
	Common fractions to decimals		2004-02-12
		From A parent: I'm trying to help my son work with turning fractions into decimals and this seems foreigh to me after 20 years of not being in school. Can you give me a few illustrations and/or examples of how to do that?? Answered by Penny Nom.
	Profit		2004-02-12
		From Mohamed: if i bought some thing with 100$ and the saller told me that his profit was 30% how can i know the actual price of the good Answered by Penny Nom.
	Zero		2004-02-12
		From Syazwan: can you tell me who and when the number zero was discoveredd Answered by Penny Nom.
	Three numbers are added in pairs		2004-02-12
		From Jane: When three numbers are added in pairs, the sums of the pairs are 22, 39, and 45. What are the three numbers? Answered by Penny Nom.
	Driving from Sarnia		2004-02-11
		From Jane: "Crystal drove from Sarnia at 80km/hr. Emily left Sarnia one hour later and drove along the same road at 100km/hr. How far from Sarnia did Emily overtake Crystal?" Answered by Claude Tardif.
	Digits in the decimal expansion		2004-02-11
		From Leslie: In the decimal expansion of 1/17 what digit is in the 1997th place? Answered by Penny Nom.
	Sums and differences		2004-02-10
		From David: The sum of two whole numbers is 63. The difference between the numbers is 10. Find all the possible pairs. Answered by Claude Tardif and Penny Nom.
	Three times a year		2004-02-09
		From Graham: What is the term for a report that is submitted three time a year or at the very least a prefix term for one third Answered by Harley Weston.
	Will be shinning in 36 hours?		2004-02-08
		From Kim: It is noon, you lunch hour, but you cannot go out because there is a terrific hailstorm. Turning on you radio you hear that weathercaster predicts that the hail will change to rain and that it will pour all day today. How can you determine whether the sun will be shinning in 36 hours? Justify your answer. Answered by Penny Nom.
	Graphing lines		2004-02-08
		From A student: how do you solve y=1\3x+3 and y=1\3x-3 by graphing? Answered by Penny Nom.
	A/30 + B/105 = (7A + 2B)/x		2004-02-05
		From Jim: If A/30 + B/105 = (7A + 2B)/x and A, B, and x are integers greater than 1, what must x equal? Answered by Penny Nom.
	A quadratic word problem		2004-02-04
		From Carl: A walkway of uniform has 72m2 and surrounds a swimming pool that is 8m wide and 10m long. Find the width of the walkway. Answered by Penny Nom.
	$20,000 at 25% compounded daily		2004-02-03
		From A student: Hi there, I'm tying to figure out how much interest I would pay on 20,000 if it was 25% compounded daily. Answered by Penny Nom.
	Geometric sequences		2004-02-03
		From Alan: hello, I am a junior in precalculus. we started working on geometric sequences today, it makes perfect sense on how it works. but why is it called that? if you could send me an answer to why geometric sequences have that name, I would be much appreciative. Answered by Chris Fisher.
	The volume of a tetrahedron		2004-02-03
		From Joseph: How do I calculate the volume of a bird tetrahedron. I'm trying to find out to get extra credit. I came with this idea while making a origami tetrahedron. Joseph P.S. Do you by any chance have instructions for orig ami figures. If you do, please send me some. Thanks! Answered by Penny Nom.
	The incline of an exercise machine		2004-02-02
		From An exerciser: This is a question about incline percentage. On an exercise machine if the elevation is raised 3 and one half inches from a level position then what would be the incline percentage? Answered by Penny Nom.
	Angular speed		2004-02-01
		From Rachel: A 4 inch pulley on a motor makes 1500 revolutions/minute. It is connected to an 8 inch saw blade. a. Find the angular speed of the pulley in radians/minute b. Find the angular speed of the saw in radians/ minute Answered by Harley Weston.
	Logarithms		2004-02-01
		From A student: Where did the word logarithmic come from? Where/whom did it originate? Answered by Harley Weston.
	Pairing boys and girls		2004-02-01
		From Terri: Suppose 7 boys and 7 girls are assigned to work in pairs of one boy and one girl. Explain what equation can be used and how you would use a simpler problem to solve these types of questions. Answered by Penny Nom.
	The vertex of a cone		2004-01-29
		From Richard: Please help me explain to my fourth graders as to why a cone has a vertex even though it does not have any straight edges. Answered by Chris Fisher.
	Intersecting a line and a curve		2004-01-29
		From Senthil: between line and curve how can i find intersection point? could you write me the formula and explanation also sir. Answered by Penny Nom.
	Is a cylinder a type of prism?		2004-01-29
		From Rebecca: Is a cylinder a type of prism? Answered by Penny Nom.
	Order of operations		2004-01-28
		From John: I am trying to find out any information concerning the development of the order of operations. for example, when (why/how) did it become the case that 2 + 3 x 5 =17, rather than 25. any insight is appreciated. Thank you. Answered by Penny Nom.
	Sin(3x), cos(3x) and tan(3x)		2004-01-28
		From Jon: What is the identity for cos3x, sin3x, and tan3x? In class, we learned double angel identities and were asked to find out the identity to these three trig functions. If you can help, please do. Also, i know that the cos4x- sin4x is the same as cos2x. Is cos8x-sin8x = cos2x also true? Thank you.s Answered by Chris Fisher.
	Sets		2004-01-27
		From Susan: My child has the following problems to solve, and we are puzzled. 1. Compare the subset symbols to the inequality symbols of less than or greater than. 2. If A, B & C are sets such that A has 47 elements, B has 32 elements, and C is a proper subset of B, what can you say about the number of elements in the following sets: A U B? A intersect B? B U C? and B intersect C? Answered by Penny Nom.
	The London marathon		2004-01-27
		From Nina: After a years training, Minnie Midriffe increased her average speed in the london marathon by 25%. By what percentage did her time decrease?o Answered by Penny Nom.
	Ounces into cubic centimeters		2004-01-27
		From A student: how do you convert ounces into cubic centimeters? Ex: how does 12 oz. change into cc. Answered by Penny Nom.
	Three digit combinations		2004-01-27
		From Kevin: how many 3 digit combinations can be made with 0-9. i have been told only 1,000. when i asked jeeves the response was 750 without using any digit twice. i have entered a raffle and received a ticket with 4 sets of 3 digit numbers. Answered by Penny Nom.
	Lead weights		2004-01-26
		From Jeff: I am making a mold for my decoy anchors. I need 10 - 12 lead ounce weights. How would I determine the liquid measurement for that weight? For example if I melted down 10 ounces of lead how many cups would that be or quarter cups etc? I would like the formula if I could and good instructions on how to use the formula. Answered by Penny Nom.
	Polynomials		2004-01-25
		From Bruce: A polynomial is defined as Polynomial functions are functions that have this form: f(x) = anxn + an-1xn-1 + ... + a1x + a0 The value of n must be an nonnegative integer. That is, it must be whole number; it is equal to zero or a positive integer. The coefficients, as they are called, are an, an-1, ..., a1, a0. These are real numbers. Questions: why must n be positive? what are some historical facts about the evolution of the definition? Answered by Harley Weston.
	|x^2 - 12x| = 8		2004-01-24
		From Sherre: |x2 - 12x| = 8 Answered by Penny Nom.
	Bundles of asphalt shingles		2004-01-24
		From Larry: According to my study material 4:12 multiplying factor for shingles is 1.054. The question reads as follows: A building with a floor plan of 3350 sq. ft. and a roof slope of 4:12 will require _______ bundles of standard asphalt shingles. Answered by Harley Weston.
	x^x^x^x^...		2004-01-23
		From Ryan: you have a number say x and it is to the power of x which is to the power of x and so on infinite times like x^x^x^x^x^x^x^... i have to figure out what x is so that the answer is always 2 Answered by Penny Nom.
	A counterfeit coin		2004-01-23
		From Kim: You are considering buying 45 silver coins that look alike, but you have been told that one of the coins is a lightweight counterfeit. Find the least number of weighings on a balance scale that you can use to be certain you have found the counterfeit coin? Answered by Penny Nom.
	g on Mars		2004-01-22
		From RC: To measure the acceleration on Mars an object is dropped from a height of 160m. It takes 10s for this object to hit the ground. What is the value for g on Mars?g Answered by Penny Nom.
	A game with some strings		2004-01-22
		From Trudy: A boy holds 6 pieces of strings in his hands with the ends protruding above and below. The top ends are tied together in pairs and then the lower ends are tied together in pairs. What is the probabilty that the pieces of string are all joined in one loop? What is the probability of obtaining two loops? Can you generalise this to solve the problem for 2n blades of grass? Answered by Andrei Volodin and Penny Nom.
	BEDMAS		2004-01-21
		From Jessica and her mom: my mom and I were wondering 2 things. 1. what is the reason for having bedmas. 2. 5+5-4+[6x3-(6+1-3x2) -5+9] Answered by Penny Nom.
	A problem with sets		2004-01-20
		From Jason: Given that the universal set S is the set of all sports fans, and F={x|x is a football fan} B={x|x is a basketball fan} H={x|x is a hockey fan} a)Describe (F^B)' (f intersect b)' in words b)Draw a Venn Diagram and shade the region that represents the set of football fans or both basketball and hockey fans. Answered by Penny Nom.
	What is the speed of the automobile?		2004-01-20
		From Rita: An automobile travels toward Nashville from Cookeville. It takes 33 minutes to travel from Cookeville to Manchester, which is a 36 mile distance. If the driver continues at this pace, what is the speed of the automobile? Answered by Penny Nom.
	A parabolic arch		2004-01-19
		From Teresa and Robyn: A bridge over a river is supported by a parabolic arch...arch is 200 m wide at water level...the maximum height of the arch is 80 m..what is the height of the arch measured from a point on the water 40m from the centre of the arch Answered by Penny Nom.
	The product of any n consecutive integers		2004-01-18
		From Fazia: I have to prove that the product of any n consecutive integers is divisible by n!(eg:the product of five consecutive integers is divisible by 5!) It's easy enough to plug in numbers and prove it is true, but i'm finding it difficult to come up with a proper proof. Answered by Claude Tardif.
	Combinations of 12 numbers		2004-01-18
		From Cheryl: I would like to know the total possible combinations using the numbers 1-12. We would also like to know the formula used to calculate the number of combinations. Answered by Harley Weston.
	Cubic yards in a concrete wall		2004-01-18
		From Danny: I am studing for my contractors exam. I am haveing truble with a few questions. I have the answer to the problems but I dont know how to get them my self. please help How many cu. Yds. Of concrete are in a wall that is 150' long and 8'4" high an d 8' thick Answered by Penny Nom.
	Some trig problems		2004-01-18
		From Weisu: I have some questions about pre-calculus. (1) (2(cos(x))^2)+3sin(x)-1=0 (2) sin(x)cos(x)=(1/2) (3) 3sin(x)=1+cos(2x) (4) tan(x)*csc(x)=csc(x)+1 (5) sin(arccsc(8/5)) (6) tan(arcsin(24/25)) (7) arccos(cos(11pi/6)) the last problem uses radian measure. Answered by Penny Nom.
	Two consecutive negative integers		2004-01-17
		From Amanda: Find two consecutive negative intergers whose product is 182. Answered by Penny Nom.
	Six letter words		2004-01-17
		From Debora: An anthropologist discovers an isolated tribe whose written alphabet contains only six letters (call the letters A, B, C, D, E, and F). The tribe has a taboo against using the same letter twice in the same word. It's never done. If each different sequence of letters constitutes a different work in the language, what is the maximum number of six- letter words that the language can employ? Answered by Penny Nom.
	Arrays of pennies		2004-01-17
		From Kathleen: How do I create an array of 100 pennies? Answered by Penny Nom.
	Volume of a tube		2004-01-14
		From Mike: where can you find how to get volume of a tube: 3 in across x 3 inch high 5 in across x 5 inch high same formula for both. ONE will get the other. Answered by Penny Nom.
	3/8 as a decimal		2004-01-13
		From A student: My Math Midterm is tommorow and I am stumped... how do you turn 1 and 3/8 into a decimal... I know the answer is 1.375 but I just copied down what the teacher wrote on the board. Oh, and what are the three cases of percents? Answered by Penny Nom.
	What is a Fact Family?		2004-01-13
		From Keisha: I am helping my child with his homework. The worksheet we are trying to do ask the child to choose a number from inside of a circle and then one from inside of a triangle and use the number to build a fact family. The title of the worksheet is "Building a Fact Family House". I noticed that Silver Burdett Ginn,Inc. was the publisher of the book the worksheet came from so I was on the website trying to find an answer to my question. My question is "What is a Fact Family?" Answered by Judi McDonald.
	Polynomial division		2004-01-13
		From Efrat: How do we divide the following polynomials? (x3 + x2 - x + 2) / (x + 2) Answered by Penny Nom.
	Twelve acres		2004-01-13
		From Heather: I am looking at buying a property that includes 12 Acres of land and I am trying to visualize what this size is equivalent to. I have searched your site and figured out how many square feet it is but I was hoping that you could apply 12 Acres to something tangible, like a football field! Answered by Penny Nom.
	Why is the letter J used for the integers?		2004-01-13
		From Amanda: Why is the letter J used to represent intergers as a symbol? Answered by Penny Nom.
	The square footage of an acre		2004-01-12
		From Paul: What is the square footage of an acre of land assuming all four sides are equal in length. Answered by Penny Nom.
	Permutations and combinations		2004-01-11
		From A student: Are there more permutations than combinations for a series of 4-digit numbers with the integers 0-9? Can you illustrate calculations? Answered by Penny Nom.
	Cubic furlongs		2004-01-11
		From A student: 1 mile=8 furlongs, how many cubic furlongs in a cubic mile? Answered by Penny Nom.
	Reflex angles		2004-01-09
		From Sonya: My daughter is searching for examples of reflex angles. We already have the hands of a clock but still need another example. Can you help us. Answered by Chris Fisher.
	Geoboards		2004-01-09
		From Elissa: What is a geoboard? I have a young girl in grade eight math who has a math question using a geoboard. Answered by Diane Hanson.
	The area of a lot		2004-01-09
		From Lea: I have a problem. I am interested in purchasing a piece of property which has the following dimensions. It is 259.10 Feet on the north side x 61.20 Feet on the east side x 217.80 Feet on the south side x 196.70 Feet on the west side. It looks like an irregular rectangle shape. How do you figure out the square footage on this irregular sized property, and what is the correct square footage answer. I have attached a survey map. Answered by Harley Weston.
	Inequalities		2004-01-08
		From Michael: How do you use inequalities in your job and in your everyday life? Answered by Penny Nom.
	Dividing zero by infinity		2004-01-08
		From Jason: What do you get when dividing zero by infinity? Our Calculus teacher was pretty sure that the expression was indeterminate from. However, if this is so...Why? Zero divded by any number (except zero) is zero, true. Any number (except infinite) over infinite is zero. So, why isn't Zero divided by infinite zero. A simpler way if I had 4 potatoes and was to split them among 2 friends, each friend would get 2 potatoes. However, if I had 0 potatoes and split them a infinite number of ways, each person would still have 0. Explain please! Answered by Penny Nom.
	Unusual occurances		2004-01-08
		From Martin: My wife and I have a question about the probability of something that happened to us a few years ago. So far, no one has been able to give me even an approximate answer. On my 32nd birthday, my wife and I went out to eat at local Japanese hibachi style restaurant. At the restaurant, couples/families are sat together around the hibachi where the cook performs a show. There was a fifteen minute or so wait, so my wife and I sat in the lounge waiting for our name to be called. When they called our names for the reservation, this is what happened. The first group called was the Martin family. Then they called the Francis family. We were the next family to be called, the Ashton family. My full name is Martin Francis Ashton! I think the odds of that happening to someone are very unlikely, but it did, and there is more. Next, we were all sat at the same table in that order, "Martin" family, "Francis" family, then us, the "Ashton" family. Again, it formed my full name! Answered by Penny Nom.
	Is zero even?		2004-01-07
		From A secretary at an elementary school: Is zero an even number? Answered by Penny Nom.
	The sides of a circle		2004-01-07
		From Helena: My name is Helena and I am 10 years old. On a resent math exam I was asked the question" How many sides does a circle have?" and I wrote down none. The teacher said the answer was one side. Answered by Chris Fisher.
	Laying decorative bricks		2004-01-07
		From Duk: Loren is laying decorative brick along both edges of the 21-meter walkway up to his house. Each brick is 0.26 meters long. He is placing the bricks end to end. How many bricks does he need to do the job? Answered by Penny Nom.
	Factoring expressions		2004-01-03
		From A student: I'm having trouble factoring expressions that aren't monic. I can do things like x2-9x+8, but problems like 12x2+5x-3 have me stumped. I also have a question about factoring out common factors. In a problem like x2-18x+81, wouldn't you divide by 9? But what happens to the x2, is it x2/9? Answered by Penny Nom.
	37 with four 4'2		2004-01-03
		From Myra: Using four fours and only four fours to get an answer of 37. Answered by Claude Tardif.
	Solving an equation		2004-01-03
		From A student: the question is to solve and check equations and the question is 2n + 3n + 7 = -41 Answered by Penny Nom.
	Making a windmill		2004-01-02
		From Matthew: I am a farmer in Ontario. It has been almost 20 years since high school. I am toying with making a windmill. The output chart for the the old generator I have is shown below. Before I tear it appart I would like to develop a formula from the chart that can predict the output at various speeds. Answered by Penny Nom.
	Four digit combinations		2003-12-31
		From A student: i need all 4 digit combinations using 0-9 please Answered by Penny Nom.
	Fractions		2003-12-31
		From Jae: Replace the question marks with numbers that will make the sentence true. 1.1/3=?/9=?/6 2.?/18=8/12=4/? 3. 3/?=12/?=9/? 4.?/3=?/21=?/7 5. Which problems have more than one possible answer? Why do you think this is so? Answered by Penny Nom.
	A new way to measure randomness		2003-12-31
		From Stephanie: Last year, I did a science project in which I asked, "Which shuffles better, an automatic card shuffler or shuffling by hand?" To measure this I decided the "best" shuffler was the one to become random first. Last year, to measure randomness, I numbered cards 1-52 and had the subjects shuffle them until they broke up the rising sequences or reached 10 shuffles. (Usually 10 shuffles came first...) Anyway, I did the same thing with the automatic card shuffler, and, as hypothesized, the automatic card shuffler randomized the deck first. This year, I have decided to continue the project. The problem is, I need a new way to measure randomness without the use of fancy computers or something. I have searched the Internet, I have posted my query on websites based on math, and I have searched the local library. I have found many useful things on the Internet, but none of them can tell me a new way to measure randomness. I cannot do a perfect shuffle, and I am not terribly gifted in the art of using computers. If you have any information (anything will help) or advice, I would be greatly obliged. Answered by Andrei Volodin.
	The trapezoidal rule		2003-12-31
		From Prashanth: I have a set of XY co-ordinates(say 49 points),I want to find the area enclosed by the curve joining them and the axes.I do not have an equation for the curve and I am not able to fit a curve given the points.I use the trapezoidal rule (Y1+Y2/2)*(X2-X1), Is it right? can I do this with any other method? Answered by Penny Nom.
	Ratios and proportions		2003-12-31
		From Frank: I would like to know how you use 'ratios and proportions' in everyday life. Answered by Penny Nom.
	Some number problems		2003-12-24
		From Shruthi: 1. Write 31 using 3 five times 2. Write 100 using all the 10 digits just once . . . Answered by Penny Nom.
	Percent increase		2003-12-24
		From Frank: How does one figure the percent of increase or decrease in the cost of an item? Answered by Penny Nom.
	Making a cone		2003-12-22
		From Tracie: I am working on a craft project at home and I have been given the following information: 16" tall and 13" diameter at base, with 1 and 1/2 " opening at top. Is there a basic formula for creating a cone with this info? Answered by Claude Tardif and Penny Nom.
	400, 100 and 2500		2003-12-21
		From A student: A person likes 400 but dislikes 300 He also likes l00 but dislikes 99 He also likes 2500 but dislikes 2400 Which of the following does John like 900, 1000, 1100 or 2400 Answered by Penny Nom.
	The angles in a regular polygon		2003-12-21
		From Ernie: If i have a measure of one interior angle of a polygon, how can i find the number of sides it has? Answered by Penny Nom.
	Adding percentages		2003-12-19
		From Paula: How do you add percentages e.g 90% + 80% + 60% + 54% + 25% = ? Answered by Penny Nom.
	Business trip		2003-12-19
		From Ameer: A businnessman drives from Washington, D.C., to Boston, a distance of 442 miles, and then makes the return trip. On the way to Boston, he drives 65 miles per hour, taking an 1-hour rest stop during the drive. After finishing his business in Boston, he make the return trip driving at 60 miles per hour and takes a 45-minute rest stop halfway through the trip. Which leg of the journey, Washington, D.C. to Boston, or Boston to Washington, D.C., takes the longer time? Answered by Penny Nom.
	The area of a plot of land		2003-12-19
		From David: I have a plot of land that I cannot find the square footage of. Actually my home sits on a large lot. Local building codes require that a home is seated on no less than 7500 square feet of land and have no less than 50ft of road frontage (the rear of the lot has 65ft of frontage on another road). I need to know if I have enough square footage to build a second home on the rear lot. The lot has five sides. Only one angle is a 90 deg. angle. The others I cannot determine. Of the 4 remaining angles, all 4 angles are obtuse, or greater than 90 deg. The dementions are 89.19' x 130' x 118.52' x 65' x 170.94'. The two legs that make the 90 deg angle are 89.19' and 170.94'. The measurements fall in order using the 90 deg angle as the point of origin and proceeding clockwise, 89.19', 130', 118.52', 65', 170.94'. I have used all the skill I can muster, however, it has been a long time since school and regretably I cannot find an answer. Answered by Penny Nom.
	Multiplier and multiplicand		2003-12-17
		From Karen: The K-5 curriculum states that at a grade 5 level students should "understand and use the terms multiplier, multiplicand" The curriculum defines 'multiplicand' as " a number being multiplied by another number. A factor." There is no definition given for 'multiplier' Question: Define these words- are they just other words for 'factors'. If so, how important is it that students use these terms? It would seem like 'factors' would be the better choice of words to use. If multiplcand refers to eg. the first factor in the equation and the 'multiplier' the seond term, (if in fact it does)- is this not confusing for students when we teach them that multiplication is commutative? Answered by Penny Nom.
	Binomial distribution		2003-12-17
		From Lesley: my daughter is having difficulty with the following formula P(X=x) = ( n over x) px (1-p) n-x The teacher has given them the formula but not taught them how to apply it or understand it. Answered by Penny Nom.
	The hour hand and the minute hand		2003-12-17
		From Minnie: When you are looking at the clock at 12:00 the hour hand and minute hand are exactly together. (one on top of the other). Between 1:00pm and 1:15pm there is another time when the hour and minute hands are exactly together again. Answered by Penny Nom.
	Factoring in		2003-12-16
		From Priscilla: How can you use solving by factoring in real life applications? Answered by Harley Weston.
	An elliptical race track		2003-12-16
		From Judy: the inner rail of a race track is a perfect ellipse. the track is a standard width all the way around. how can i prove that the outer rail is a ellipse? Answered by Penny Nom.
	How far can you see?		2003-12-15
		From Judy: How far apart, assuming no obstacles, can two people stand and still see each other? i know this deals with the curvature of earth, but i can't figure out the formulas involved. Answered by Chris Fisher.
	(2^ 20,966,011) - 1		2003-12-12
		From Reid: Can someone please explain, answer and/or solve this: (2^ 20,966,011) - 1 I don't know what it means, my boss sent it out, I'm assuming it is to be solved but don't know what it is, any prompt help would be appreciated, very much so, in fact, thanks,........... Answered by Penny Nom.
	Math jobs		2003-12-12
		From Veronica: Do you know a couple of jobs I can get when I am older in Math? Answered by Harley Weston.
	A snowball melts		2003-12-11
		From Adam: A spherical snowball has diameter 10cm and density 0.75g/cm3. It is placed in a cylindrical can with diameer 12cm. After the snow melts it turns to water with density 1.0g/cm3. What will be the depth of the water in the can (to 1 decimal place)? Answered by Penny Nom.
	Diamonds and Pearls		2003-12-11
		From Lauren: A crown holds a total of 3080 jewels. It is made up of diamonds and pearls. There are 10 times as many diamonds as there are pearls. How many pearls are there? Answered by Penny Nom.
	1/0 = ??		2003-12-09
		From Lisa: One of my students asked me a fractions question. She knows that 0/1 equals 0 but does 1/0 also equal 0? Answered by Walter Whiteley and Penny Nom.
	Non-euclidean geometry		2003-12-08
		From Geoffrey: How can you use non-euclidean geometry to navigate on a sphere? What geometers did work in this area? Answered by Chris Fisher.
	Matrices		2003-12-05
		From Julie: I am doing a project and need to find some mathematiciens who had an influence in matrices. I can't seem to find any when I search online. Could you please help me with this? Answered by Judi McDonald.
	Prescription drug coverage		2003-12-04
		From Khadijah: Last week congressional approval was given to legislation involving prescription drug coverage for seniors. One summary of the legislation explains that it is estimated that in 2006 a senior will pay a premium of $35 per month, then pay their first $250 in pharmacy bills. After the bills reach $250, the coverage would pick up 75% of their bills that bring their total bills between the $250 and $2250 mark. After their bills reached a total of $2250, the senior would be responsible for all bills bringing their total annual bills between $2250 to $5100. Then any bills after the $5100 mark has been reached will be 95% covered by the insurance. Using this information, letís analyze the situation of a senior who accumulates $6000 in pharmacy bills over one year and has the insurance coverage. Over the course of this year, how many dollars will the senior pay? Answered by Penny Nom.
	What percentage of 6 billion is 40 million?		2003-12-03
		From GiGi: What percentage of 6 billion is 40 million? Answered by Penny Nom.
	The median		2003-12-03
		From Christiane: how do you find the median of this group of numbers:63,75,29,37,49? Answered by Penny Nom.
	Non-Euclidean geometry		2003-12-03
		From Geoffrey: What are the applications of Non-Euclidean geometry (especially hyperbolic and spherical)? Answered by Walter Whiteley.
	Four digit combinations		2003-12-02
		From Deen: Question: i have 3 numbers and i have to come up with all the possible 4-digit combinations with those 3 numbers. Is there a formula for it? Example: given numbers are 1-2-9 and you need to break a 4 digit code. what are the posiible combinations that u can come up using the 3 numbers? Answered by Penny Nom.
	A locus		2003-12-02
		From Tash: Question: a)Find the equation of the locus of the point P which moves so that its distance from A(1,2) is always three times its distance from B(5,6) b) Show that this locus is a circle and states the coordinates of its centre and the length of its radius Answered by Penny Nom.
	Finding angles		2003-12-02
		From Jason: I AM TRYING TO SOLVE A TRIG PROBLEM AND HAVE FORGOT HOW TO DO IT. WHAT I HAVE IS A RIGHT TRIANGLE WITH SIDE A BEING 14 FEET AND SIDE B BEING 3 FEET, USING PYTHAGOREAMS THEOREM SIDE C SHOULD EQUAL 14.318 FEET ON A RIGHT TRIANGLE BUT I AM TRYING TO REMEMBER HOW TO FIND MY ANGLES OTHER THAN THE ONE THAT IS 90 DEGREES. Answered by Penny Nom.
	The area of a triangle		2003-12-01
		From A student: Find the Area of Triangle ABC A(-3,2) B(4,0) C(0,8) Answered by Penny Nom.
	Room and board fees		2003-11-29
		From Jennifer: A certain university wishes to determine room and board fees for the next academic year. For the current year, the fee is $3600 per student and 1800 students are living in the residence halls. Past data suggests that for every $300 increase in the semester fee, 200 fewer students will choose to live in the dorms. There are also costs to the university associated with the residence halls. The fixed costs total $2,000,000 per semester. the variable costs are currently $1000 per student but will fall $100 per student for each decrease of 100 students. Your task is to help the university determine the optimal fee. Assume linear relationships between the number of students and the fee and between the number of students and the cost per student Answered by Penny Nom.
	5.75 acres of land		2003-11-28
		From Susan: We own 5.75 acres of land here in El Paso Tx. Some one wants to buy all or some of our land...to build homes on...but.. I can't figure a few things 1. our land is Almost exactly 500x 500x500 x500 ft square proprty based on this can you tell me the approx perimiter measurements of EACH acre we wish to sell approx 1/2 of this 5.75 acres ...or a tad bit less.. these are all approx measurements what I also need to know is.. how many 50ft x 100ft lots are in each (1 )Acre??? Answered by Penny Nom.
	A fish tank		2003-11-26
		From Bill: How do I work out the volume and weight of water in a fish tank that is 36in x 14in x 12in? Answered by Penny Nom.
	Mr.Carter is very cautious		2003-11-26
		From Bob: Mr.Carter is very cautious. He decides to invest in only three stocks: one low stock, one high stock, one medium stock. Given that the expected annual yields are 6% for low stock, 7% for medium stock, and 8% for high stock, he wants his investment in medium stock to be half of his total investment in low and high stock. How much should I invest in each type fo stocks to expect a total annual return fo $650 form my investments? Answered by Harley Weston.
	Area of an equilateral triangle		2003-11-25
		From Jared: Can you help me understand why the area of a equilateral triangle is the square root of 3 divided by 4 times the lenght of the side squared? Answered by Penny Nom.
	An inequality whose solution is all points		2003-11-25
		From Katie: Hi my name is Katie and I am in the 9th grade and I would like help on this question. Is it possible to have a system of inequalities whose solution is all points? 1.I need to know why (explanation) 2.how to do it(example) Answered by Penny Nom.
	The volume of an irregular tetrahedron		2003-11-24
		From Peter: How do I calculate the volume of an irregular shaped tetrahedron where:- side a = 1.4 m side b = 1.4 m side c = 1.2 m and height = 0.75 m at the junction of sides a and b. Answered by Penny Nom.
	Markup, profit and margin		2003-11-24
		From Ali: I have question regarding Margins, Markups and Profit Purchase price = $ 10.00 Margin or Markup ?? = 40 % Therefore Selling Price = 10/0.6 = $ 16.67 Profit ? = (16.67-10)/10 *100 = 66.67% or is the profit = (16.67-10)/16.67*100 = 40 % Can you please clarify What is Margin, Markup and Profit Answered by Penny Nom.
	Difference of squares		2003-11-24
		From Susie: Factor assuming that n is a positive # Problem: (I will give it to you in words beacuse I don't know how to do exponents on the computer.) Forty-five r to the 2n power minus five s to the 4n power. I was hoping you could walk me through it not just give me the answer. Answered by Penny Nom.
	An octagon shaped bed frame		2003-11-23
		From Trish: My son and I are making an octagon shaped bed frame. We are going nuts trying to figure out what angle to cut the boards to make an outline of an octagon. It seems that the 8 inside angles of the 8 "corners" are 120*, but what is the angle that the 2x6 wood should be cut so that they will angle together to form the outline of the octagon? Answered by Penny Nom.
	Laws of sines and cosines		2003-11-23
		From A parent: On the one side of a stream lines PA= 586.3 feet, PB = 751.6 feet are measures, angle APB being 167 degrees and 36 min. Q is a point on the opposite side of the stream. Angle PAQ=63 degress and 18 min and PBQ=49 degrees and 24 min. Find PQ. Answered by Penny Nom.
	The volume of a cube		2003-11-22
		From A student: i have a cube, and the line that cuts threough the middle of the cube across to the other side is 4 radical6. what is the volume of the cube? Answered by Penny Nom.
	Aristotle		2003-11-21
		From John: I would like to know how aristotle was related to math. In all my searches I have found only philosophy etc. But not any math. Answered by Penny Nom.
	AB/AP=AP/PB		2003-11-20
		From James: My name is James McBride. I'm having a difficult time with a pre calculus problem, which goes as follows: "show that AB/AP=AP/PB is equal to (1+5^1/2)/2 (one plus the sqaure root of five with the sum divided by two. I can't do the square root sign, sorry.) I have tried to solve for PB in terms of the other varialbles and then work the quadratic equation. THAT DOES NOT WORK!!!! I am befuddled. Please help me. I am a student of secondary level. Answered by Penny Nom.
	Four digit numbers		2003-11-20
		From Rob: Hello, I sure hope you can answer this question. I got into a discussion at work about how many possible combinations there are for a four digit number using the numbers 0 through 9. This was in reference to a discussion about the lottery. I said there was only 10,000 possible combinations. My friend said that there was many times more, but he could not remember how to figure it out. The answer and the formula would be greatly appreciated. Answered by Penny Nom.
	962 Sq. Ft. is what percent of 2656 Sq. Ft		2003-11-20
		From Jon: 962 Sq. Ft. is what percent of 2656 Sq. Ft Answered by Penny Nom.
	4(r-2) = r(2+8)		2003-11-20
		From Angela: I not going to give you the problem that I have, but a problem like it. 4(r-2) = r(2+8) I get mix up trying to solve a problem like this could you help me. So that I will be able to handle the ones on my homework. Answered by Penny Nom.
	A riddle		2003-11-19
		From Sarah: Ok, our teacher gave us this riddle, and I cannot for the life of me figure it out. He said that there are three problems with the following proof: Answered by Penny Nom.
	Systems of equations		2003-11-19
		From Scott: I hope that u can help me....I am a college student taking a class in Pre Calculus.....I have homework due this Friday and it counts a BIG Percentage on my FINAL grade.....I am getting mixed up and can not figure out a few problems.....Please help me..... Method Of Subsitution Problem 1. y- 8x = -5 x(squared) + y(squared) = 25 Problem 2. y = x(squared) - 2x - 6 Y = x(squared) - 4 Answered by Penny Nom.
	A point and a line		2003-11-19
		From Meenakshi: Given a line segment L(x1,y1) to (x2,y2) and a Point P(x3,y3). I need the formula to find a point on the line L that is closest to the point (x3,y3). Answered by Penny Nom.
	If 1 is neither prime nor composite...		2003-11-19
		From Joshua: if 1 is neither prime nor composite...what is it called? Answered by Claude Tardif and Penny Nom.
	If 1 is neither prime nor composite...		2003-11-19
		From Joshua: if 1 is neither prime nor composite...what is it called? Answered by Claude Tardif and Penny Nom.
	Unmatched socks		2003-11-17
		From Shannon: i have 6 pairs of socks lying unmatched in my dresser drawer. Each pair is a differnt color (brown, black, red, yellow, green, purple) When i wake up in the morning, I randomly grab 2 of the loose socks and put them on without looking. If two socks are randomly selected from the drawer, what is the probability that they match? Answered by Andrei Volodin.
	The 4th difference		2003-11-17
		From Jack: If i had a sequence which was the same at the 4th difference, aka difference to the 4th, like: 1 5 14 30 56 96 (sequence) 4 9 16 26 40 5 7 10 14 2 3 4 1 1 then what would be the set formulars to find out a, b, c, d, and e as i know the equation has to be an4+bn3+cn2+dn+e Answered by Penny Nom.
	Adding fractions		2003-11-16
		From Ken: My name is Ken and I am taking my GED course for my High School and have not been in a class for 35 years. I am doing this for re-training. I am at the part about fractions. Here is an example that I am having trouble with. 1 3/7 + 4 2/3 + 11/21 They have no common denominators. Could you PLEASE help me. If you could send me a step by step explanation it would be greatly appreciated. Answered by Penny Nom.
	Three problems		2003-11-16
		From Megan: My name is Megan and I am a junior in high school. Our teacher gave us a few xtra credit questions and I need some help. Answered by Penny Nom.
	Divisibility by 7		2003-11-14
		From A student: how do you test a number to see if it is divisible by 7 or not? Answered by Penny Nom.
	Lines		2003-11-14
		From A student: What is a name that a group of lines pass through? Answered by Chris Fisher.
	root24 = 2 root6		2003-11-13
		From Burke: I know that all algerbra can be represented visually, for example: Y=9x+3 is a line on a two dimentional plane. Could Math Central please send me a visual representation of the proccess of simplifying square root like root24 equals 2root6 Answered by Penny Nom.
	Diagonals in an octagon		2003-11-13
		From Glenn: Question 1. What is the probability of choosing the longest diagonal in an octagon? Question 2. Probability of choosing the shortest? Answered by Andrei Volodin and Penny Nom.
	A trig identity		2003-11-12
		From A student: I can't prove this identity. Can you please help me? (1-tanx)/(1+tanx)=(1-sin2x)/(cos2x) Answered by Penny Nom.
	What is a number that has exactly 13 factors?		2003-11-09
		From Mary: What is a number that has exactly 13 factors? Answered by Penny Nom.
	Mixing Brazil nuts and cashews		2003-11-09
		From Bob: Cashews are sold for 1.20 per 1/4 pound and Brazil nuts are sold for $1.50 per 1/4 pound. If you mix 20lbs of Brazil nuts, how many cahsews would it take to make a mix that sells for $1.30 per 1/4 pound? Answered by Penny Nom.
	A least squares line		2003-11-09
		From Michelle: Hooke's Law asserts that the magnitude of the force required to hold a spring is a linear function of the extension e of the spring. That is, f = e0 + ke where k and e0 are constants depending only on the spring. The following data was collected for a spring; e: 9 , 11 , 12 , 16 , 19 f : 33 , 38 , 43 , 54 , 61 FIND the least square line f= B0 + B1x approximating this data and use it to approximate k. Answered by Penny Nom.
	Greatest Common Factor		2003-11-08
		From Beth: How do you use the Greatest Common Factor in addtion and subtraction of fraction? Answered by Penny Nom.
	Equal ratios		2003-11-07
		From A student: In the ratio 3:8=17__, can__be a whole number? Answered by Penny Nom.
	The product of the page numbers		2003-11-07
		From Morgan and Mom: You open a book and the product of the page numbers is 12,656. What are your page numbers? Answered by Penny Nom.
	Chisenbop		2003-11-06
		From Jaclyn: Hi there i was wondering if you would have any information on "counting on your fingers" or " Chisabop". Answered by Penny Nom.
	Intercepts		2003-11-04
		From A student: I am totally confused on how to determine intercepts of an equation and then to graph the line. For example, how to determine the intercepts of 2x-3y-12=0. Answered by Penny Nom.
	X bar		2003-11-04
		From mary: Remind me what this means: _ X Answered by Andrei Volodin.
	The length of a chord		2003-11-03
		From David: When Radius=400.00' and Arc=130.58' what is the Cord distance in feet? Answered by Penny Nom.
	A circle around an irregular polygon		2003-11-03
		From Dale: How do I find the properties of a circle that is drawn around an irregular polygon of (n) sides with the lenghts of each side given and all end points of the polygon lye on the circumferance of the circle? Answered by Chris Fisher.
	Solve for Q		2003-11-03
		From Anwaar: The problem is: QT - X ________ + H = HT QS Answered by Peny Nom.
	Cubic yards of concrete		2003-11-02
		From John: The foundation is 20' X 20' and the depth is 6", there are also three footings that are 20' X 12" X 12" each. Can you show me the equation to figure out how many yards of concrete I will need to pour the footings and foundation. Answered by Harley Weston.
	Symmetries of a rhombus		2003-11-02
		From Tonia: why cant an equal sided rhombus have 3 lines of symmetry? you have one line of symmetry on each of the diagonals, and there should be one vertically on an angle. can you please explain the rules of symmetry to me? Answered by Walter Whiteley.
	Which one has the most factors?		2003-10-31
		From Kristi: Of all the whole numbers less than or equal to 5000, which one has the most factors? Answered by Claude Tardif.
	Divisibility by 2 or 5 or both		2003-10-30
		From Abdu: How many positive integers less than 1,001 are divisible by either 2 or 5 or both? Answered by Penny Nom.
	1/x + 1/y = 5/12		2003-10-30
		From Ben: 1/x +1/y =5/12, what is the sum of x and y? Answered by Penny Nom.
	12 cookies		2003-10-29
		From Joel: there are 12 chocolate, sugar and cinnamon cookies. the probability of choosing a chocolate cookie is 1/3. the probability of choosing a sugar cookie is 1/4 what is the probability of choosing a cinnamon cookie Answered by Penny Nom.
	A rectangle on a disk		2003-10-29
		From Arthur: How do I go about solving the following problem: What is the width of the largest rectangle with a length of 16 inches you can cut from a circular piece of cardboard having a 10 inch radius? Answered by Penny Nom.
	How much time?		2003-10-29
		From Lori: I am a elementary teacher 3-6 math. We have just implemented the Houghton Mifflin Math curriculum. It seems to be quite difficult for most of our students. In order to get through all the material we need to do a lesson a day. Although the students are not getting the material that fast. Should we move on without all the students understanding the material or should we wait and remediate until they get it and be behind for the year. This isn't just a few kids its most of the kids. We are also suppose to teach to all the standards so if we don't get to them the students will not do well on the standardized tests. Answered by Diane Hanson.
	Trees		2003-10-28
		From Ali: Is there any formula for counting the number of trees (graphs)? Answered by Denis Hanson.
	Means		2003-10-28
		From Abdu: Question: 80,80,84,85,88,92,97,98 The average of the 8 numbers listed above is 88. Of the following which pair of numbers could be removed from the list without changing the average. A. 80 and 97 B. 80 and 98 C. 84 and 92 D. 84 and 97 E. 85 and 92 Answered by Andrei Volodin and Penny Nom.
	Solve for x		2003-10-27
		From Lonnie: i need help with solving equations and formulas such as -3x+b=6x, for x. I do not understand how you find x. Answered by Penny Nom.
	Knitting gauge and felting		2003-10-27
		From Sara: I wish to create a pattern to knit an item that will then be felted, thus, shrink as a result. In order to determine the proper gauge to use in creating the item, I produced a gauge swatch, noted the original properties and then the post-felting properties. They are as follow: Before Felting: 20 stitches(width) x 20 rows(height)yielded: Gauge: 3.2 stitches(width) and 4 rows(height) = 1" Dimensions: 6.25"(width) x 5.25"(height) After Felting: 20 stitches(width) x 20 rows(height) Dimensions: 4"(width) x 3"(height) How do I calculate the percentage change in size to accurately determine the number of stitches and rows needed to produce the desired dimensions for the finished (felted) item? Answered by Penny Nom.
	A rock on a string		2003-10-26
		From A student: a rock on a 4' string is rotated at 80 rpm. what is the linear speed in feet per second? in miles per hour? Answered by Penny Nom.
	Maine and Nevada		2003-10-24
		From Jimmy: From 1989 to 1990, the population of Nevada increased b y 157,000, and that of Maine increased by 30,000. In 1990, the population of Nevada was 1,206,152, and that of Maine was 1,233,223. If the populations of the two states continue to increase at the same rates, when will the populations of Nevada and Maine be the same? Write a verbal model for this problem Write an equation for the model Solve the equation and answer the question. Answered by Penny Nom.
	A parabola		2003-10-24
		From Delores: Given the vertex (4, -2) y intercept = -6 find if/where the parabola crosses the x axis? Answered by Penny Nom.
	0.810 and 0.801		2003-10-24
		From Ahmed: could you please tell me what is the greatest decimal fraction formed of the digits 0, 1 , 8? Is it 0.810 or 0.801, please give me the reason of the answer in details and the references if it possible. Answered by Penny Nom.
	Odd Pythagorean triples		2003-10-23
		From Kathleen: in a triple can a and b be odd numbers Answered by Penny Nom.
	Arithmetic in bases other than 10		2003-10-22
		From Kim: how do you add, subtract, multiply and devide in base 3, base 5, etc? Answered by Penny Nom.
	Squares in a rectangle		2003-10-21
		From Raj: Draw a rectangle with sides of 3 and 4. Divide the sides into 3 and 4 equal parts respectively. Draw squares joining the points on the sides of the rectangle. You will have 12 small squares inside the 3 x 4 rectangle. If you draw a diagonal of the rectangle, it will intersect 6 of the the 12 smaller squares. Similarly, if you have a 4 x 10 rectangle, the diagonal would intersect 12 of the 40 squares inside the rectangle. Is there an algebric equation that determines the number of squares that will be intersected by the diagonal of a rectangle? Answered by Chris Fisher.
	0.3 trillion		2003-10-20
		From Bill: What is .3 of one trillion? Answered by Penny Nom.
	Domain of a function		2003-10-14
		From Karim: Find the Domain of the Function H(x) = Log3 (4x + 7)-10 H(x) = log base 3 times 4X plus 7 minus 10 i am having problem solving these kinds of problems. Answered by Penny Nom.
	Pairs of prime numbers		2003-10-13
		From Nikolas: Use pairs of prime numbers to find all the numbers less than 50 that have only two prime factors. Make an organized list. Answered by Penny Nom.
	5x - y		2003-10-11
		From Candace: math problem 5x-y for x=12 and y=14 do you mulitilpy 5x12 and than -the answer from 14 which gives you 46? is this right Answered by Penny Nom.
	Points inside a triangle		2003-10-10
		From Laura: is there a way to establish, if a given point at coordinates (x,y) is within an area defined by three other sets of coordinates forming a triangle ABC? is T(x,y) within triangle A(x,y)B(x,y)C(x,y) Answered by Chris Fisher.
	Statistics from grouped data		2003-10-09
		From Rebecca: I have to use a suitable computer package (ie. Excel) to work out the mean and standard deviation of the following: Price Range No of Houses No of Houses £`000 Area 1 Area 2 45 and under 50 4 5 50 and under 55 7 12 55 and under 60 14 16 60 and under 70 19 18 70 and under 80 8 3 80 and under 100 5 2 I have used excel to work out mean and standard deviation before, but not in a more complicated example like this. Any advice on where to start would be greatly appreciated. Answered by Penny Nom.
	10,000		2003-10-08
		From Nathan: what two numbers make the product of 10,000. Neither number can end in a zero Answered by Penny Nom.
	Interest compounded daily		2003-10-08
		From Terie: If I owe $2000.00 @ 6.25% compounded daily for 54 days. How much do I owe in interest? Answered by Penny Nom.
	Standard Deviation		2003-10-07
		From Rebecca: I have a task to complete, which is to calculate the mean and standard deviation of something. I have done this but am then asked to write a short explanation of my findings. I know what the mean is about, and I thought I knew what the standard deviation meant too - shows the variation from the mean. However, on a task I completed earlier the feedback I got said 'you need to tell us that it is talking about the middle 66% of the data' - that has thrown me, I don't understand that. Can anyone help me get my head round this??? Answered by Penny Nom.
	Two chords		2003-10-07
		From Lori: Chords AB and CD of circle O intersect at E. If AE=4, AB=5, CE=2, Find ED. Answered by Penny Nom.
	The sketch of a graph		2003-10-07
		From A student: I was wondering how do you figure out if a graph has a horizontal tangent line. One of my homework problem was to sketch the graph of the following function; (4/3)x3-2x2+x. I set f''(x) ( the second derivative) of the function equal to zero and got the inflection point:(1/2,1/6). Also i am having trouble finding the concavity for x>1/2 and x<1/2, i am getting a different answer from the back of the book, the graph i draw looks completely different from the correct answer. Answered by Penny Nom.
	Arrangements around a circular table		2003-10-07
		From Lori: How many arrangements can 6 people be seated round a circular table? Answered by Penny Nom.
	Indeterminate forms		2003-10-06
		From A teacher: Is it possible for me to find any geometrical interpretation without using calculus to explain indeterminate forms? Answered by Chris Fisher.
	Functions, graphs and derivatives		2003-10-05
		From Jathiyah: I wanted to know how would you tell (on a graph diplaying two funtions), which funtion is the derivative of the other? Answered by Walter Whiteley.
	The slope of a tangent		2003-10-01
		From A student: find the slope of the tangent to each curve at the given point f(x)=square root 16-x, where y=5 Answered by Penny Nom.
	A rectangle in a circle		2003-09-27
		From Abdu: A rectangle ABCD is inscribed in a circle. If the length of AB is 5 and length of BC is 12, what is the area of circle outside the rectanlge ABCD? Answered by Penny Nom.
	Relatively prime		2003-09-27
		From James: what is the definition a relative prime numbers? Answered by Penny Nom.
	0/0		2003-09-25
		From Thomas: How is 0/0 ever defined. Answered by Penny Nom.
	Absolute value		2003-09-23
		From Crystal: I am trying very hard to understand Absolute Value, and I cannot seem to grasp the idea. I do not know why we use it, what the point of it is. I do not know how to use it. I know that it is always positive or zero, and I assume it relates to distance, but how can you use it in equations. Please explain it to me as simply as possible, thank you. Answered by Walter Whiteley.
	The golden ratio		2003-09-23
		From Phillip: The Golden Section can be made from an equilatereral triangle inscribed within a circle. The Golden Section is achieved by joining the mid points of two arms of the triangle to the circumference. I can prove this by erecting a perpendicular to the line outside the circle, but am interested to see how it can be proved from within the circle. Answered by Chris Fisher.
	Primes		2003-09-23
		From Julie: #1. Suppose you are given a number (n) and told that 1 and the number (n) divide into (n). Does that mean (n) is prime? #2. Suppose that p is a prime number greater than or equal to 3. Show that p+1 cannot be a prime number. Answered by Penny Nom.
	The Sieve of Eratosthenes		2003-09-18
		From Lynn: My daughter has been asked to find all the prime numbers by using the Sieve of Eratosthenes. I have no understanding what this means. Answered by Penny Nom and Claude Tardif.
	1 + 1 = 10		2003-09-17
		From David: could you please explain to me how 1+1=10 thanks Answered by Penny Nom.
	Applications of logarithms		2003-09-16
		From A student: I have a project due in my algebra two class dealing with logs and where they are used in life, but I am having trouble finding websites that relate. So I would really appreciate it if you couldhelp me. Answered by Penny Nom.
	Notation		2003-09-15
		From Kim: Question: i have a couple of questions 1. write in standard form a)4x2x8 b) 5 to the power of 4 . . . Answered by Penny Nom.
	Substitution method		2003-09-14
		From John: Hello, my name is john and while I was finishing up my work I stumbled into these problems. a/4-b=-1 a+b=11 and 6a-b=-5 4a-3b=-8 Thanks a lot. I really need some help :) John Answered by Penny Nom.
	The volume of an earthen pit		2003-09-12
		From Bruce: This shape would occur at the four corners of a rectangular shaped earthen pit with sloping sides (1:1.5). Depth is 14'. Top dimensions are 170' by 158'. After calculating the easy volume components of this shape, we are left with the end corner pieces. 21' base, 14' height, side hypotenuse 25.24' and corner diagonal 32.83'. We're confused. Thank you for any help you may provide. Answered by Penny Nom.
	The digits in 349		2003-09-12
		From Franik: in the number 349, which number has the least value, and why? Answered by Penny Nom.
	Two line segments and a plane		2003-09-11
		From Laura: Do all figures made up of two segments lie in a plane? Answered by Penny Nom.
	Area of a rectangular room		2003-09-11
		From Kelly: The area of a rectangular room is 238 square feet. The width is 3 feet less than the length. What are the dimensions? Answered by Penny Nom.
	The general equation for a sphere		2003-09-11
		From Jaidev: Is there any general equation for a sphere? Answered by Penny Nom.
	The mean house price		2003-09-10
		From Carol: Question: I have to find the mean from the following example: Price Range £000 No of Houses 55 and under 60 3 60 and under 65 6 65 and under 70 13 70 and under 80 21 80 and under 100 15 100 and under 130 7 130 upwards 1 I know when calculating the mean you use the mid points of the classes, but how does this work for the 130 upwards class? Also, does this still work given the difference in the classes (ie. 1st class is 5, 5th class is 20, etc). Any help to get me started would be greatly appreciated. Answered by Penny Nom.
	Converting from base 10 to base 5		2003-09-10
		From Susy: My son, who is 9 in grade 5 has been asked to convert base 10 numerals into base 5. His first question of: 24(10) he has calculated to be 4x5 + 4x1 = 44 (5) The next question however is the tricky one.Ý We know the answer is supposed to be 100 but we find it difficult to get this in the way he understands it. 25 (10) = _________________ 100 (5) Can you help us figure out how we reach the answer. Answered by Claude Tardif and Penny Nom.
	How high does the sequence of numbers go		2003-09-07
		From Shayna: My quetion is "How high to the sequence of numbers go"? e.g. one, ten, hundred, thousand, million, billion, trillion, and from there is my queston. Answered by Penny Nom.
	Making a square		2003-09-07
		From A student: if I am given any number (say 80 for example), how may I determine the smallest whole number integer which when multipled by it will yield a square number ? In other words if I express this as: 80Ý*ÝnÝ=ÝsquareÝnumber, what is the least value of n which will yield a square. Answered by Penny Nom.
	Consecutive integers		2003-09-07
		From Amy: I was wondering if there was a proper way to write the solution to a problem requiring consecutive integers? Is it okay to write the solution as 5,4,3,2,1 or must it be written as 1,2,3,4,5? Answered by Penny Nom.
	Order of operations		2003-09-07
		From Brian: It has to do with the 4 rules of operations, Parentheses first before operations outside/evaluate all exponential expressions/all multiplication and divisions/then all additions and subtractions. Who made these rules and when did they make them,,, I know its somewhat of an unorthadox question but I must know. I would really appreciate it. Answered by Penny Nom.
	7,473,000,000 divided by 52000		2003-09-06
		From A student: I am having trouble with a question. 7,473,000,000 divided by 52000. Our calculater gets 147311.5385. I come up with 143711.53846, and then the number starts to repeat itself Answered by Penny Nom.
	Can 2 vertical planes intersect?		2003-09-06
		From Erin: My question is can 2 vertical planes intersect? Answered by Penny Nom.
	One million seconds		2003-09-04
		From Vince: If you can write a number each second for one million seconds, how many hours would it take? Answered by Penny Nom.
	Four digit combinations		2003-09-04
		From Emma: I seriously need to find out all the four digit combinations from 0 to 9!!! My name Is Emma Dibitt and I'm going into 8th grade and I'm a student!!! Answered by Penny Nom.
	Grooming the king's horses		2003-09-04
		From Janelle: the stable boy had 90% of the kings horses groomed.the next day the king acquired 25% more horses. Now there was 105 horses not prepared for the kings men. How many horses did the king originally have? Answered by Penny Nom.
	A 16 foot ladder		2003-09-04
		From Kelly: Two buildings are separated by a three-foot alleyway. Fatima wants to use a 16 foot ladder to reach a window in the wall of one of these buildings. If she places the foot of the ladder against the base of the other building, how far up the wall will the top of the ladder reach?? Answered by Penny Nom.
	One percent of a billion		2003-09-04
		From Charles: What is one percent of one billion? Answered by Penny Nom.
	Positive, negative and zero		2003-09-04
		From Brian: Can the Value of zero be positive or can it be negative or can it be both. Answered by Penny Nom.
	The game of 24		2003-09-03
		From A student: We have a game where four numbers must equal 24 using addition, subtraction, multiplication and/or division.Ý I am stuck on the following four numbers - 12, 24, 9 and 17. Answered by Penny Nom.
	A boat travels 12 km upstream...		2003-09-03
		From Sohaib: A boat travels 12 km upstream and back in 1 hour 45 minutes. If the speed of the current is 3km/hr throughout, find the speed of the boat in still water, giving your answerÝcorrect to 3 decimal places. Answered by Penny Nom.
	Why percentage?		2003-09-03
		From Vicky: My cousin aske me a question about the use of percentages and I'm not sure how to answer it. He wants to know why when there is a sale in a shop we use percentages and not fractions or decimals. Answered by Penny Nom.
	Percentage markup		2003-09-03
		From Virginia: I am confused and hope you can help. I have looked high and low for a "chart" persay to go by when I am having to calculate markup percentages. Example if I have a List price of $1838.00 and my cost is $955.76 and I want to mark it up 30%. My colleage says it should be divided by .7 I don't understand how he arrives at .7 from 30 percent. Answered by Claude Tardif.
	Profit margin		2003-09-03
		From Chet: My salesman calculates a customers profit margin by dividing what the customer paid by what he sells for, then subtracting that answer from 1. For example a customer sells a product for $15. He bought it for $10. 15/10=.66 Subtract that from 1 and get a profit % of 33% Here's my question: If I want to figure what a reseller will sell a product for if he wants 40% margin(by the technique above), what formula do I use? Let's say I want to sell a product for 8.50, and I want the reseller to make 40% Answered by Penny Nom.
	Two row arrays		2003-09-03
		From Madalyn: My question is, what are #'s that can not be arranged in two row arrays called? Answered by Penny Nom.
	A helicopter rises vertically		2003-09-02
		From Kate: A helicopter rises vertically and t seconds after leaving hte ground its velocity is given in feet per second by v(t) = 8t + 40 / (t+2)2 How far above the ground will the helicopter be after 3 seconds? Answered by Penny Nom.
	Water in a tank		2003-09-02
		From A parent: if a tank is 48 inches long 14 inches wide and 18 inches deep if a yardstick was inserted into the tank and measured 2 inches of water in the tank how many gallons of water would be in the tank. Answered by Penny Nom.
	A theorem in geometry		2003-09-02
		From Diego: Please refer to figure in attached file. P is a point on the chord AB of a circle such that the tangent PT which touches the circle at T is equal to AB. How do we prove that PT2 = AP x BP. Answered by Dieter Ruoff and Penny Nom.
	The units digit of 57 to the 28th power		2003-09-01
		From Maria: If 57 is raised to the 28th power, what must be the units digit in the result? If you raise 7 to the 500th power, what is the numeral that will appear in the units digit position? Answered by Penny Nom.
	A 6 team schedule		2003-08-31
		From A scheduler: I saw that someone put on your web site a team schedule and you helped them figure it out.Ý I have 6 teams that want to play each other once, and believe it or not, I cannot figure it out. Answered by Penny Nom.
	20% of 40% of 500		2003-08-31
		From A student: What is 20% of 40% of 500? Answered by Penny Nom.
	Terminology		2003-08-31
		From Maria: My daughter Veronica is a rising 6th grader and has to complete some Summer Math assignments and would like to ask you three questions: ___________ are number pairs that have a product of 1. You can name any point on a plane with two numbers. These two numbers are called _____________. A _______________ is the size of a cube that is exactly 1 inch on each edge. Thanks, Answered by Penny Nom.
	The quadratic formula		2003-08-31
		From Alex: I am using Houghton Mifflin's Precalculus with Limits book, 2nd edition. However, the first chapter encompasses Algebra review, and I am stuck on a problem. All that's required is to solve the following and verify using a calculator: 3y2+6y+2=0 I have solved the problem using the quadratic formula, but from what I remember, the quadratic formula is used in the case of equations following the AX2+BX+C=0 pattern. As the problem I am attempting uses a y-variable, can I still use the quadratic formula? Since I am not sure what route to take in solving this problem, I am hoping you can assist me. Answered by Harley Weston.
	Newton's binomial theorem		2003-08-30
		From William: According to page 126 of Murtha & Willard's "Statistics and Calculus" (Prentice-Hall, 1973), Newton's binomial theorem can proved inductively. I suppose that was his method, which I would like to see. Answered by Penny Nom.
	I can Guess your birthday		2003-08-29
		From Michelle: Hi I am trying to explain to my children how this problem works. It was sent to me on the internet and I can not figure it out. They keep asking me how it works and I can not tell them. The problem is: "I can Guess your birthday:: Answered by Penny Nom.
	How many cubic yards must I purchase?		2003-08-29
		From Walt: I am trying to determine how much top soil I must purchase (by the yard). The area is 80' x 15' and I want it 3" thick. How many cubic yards must I purchase? Answered by Penny Nom.
	Converting to base 10		2003-08-28
		From Karen: My son is in 5th grade.Ý He is learning how to convert numbers from base 2 to base 10, and base 5 to base 10.Ý Can you explain it to me in the simplest terms? Answered by Penny Nom.
	Graphing a piecewise function		2003-08-24
		From Amber: How do i begin to graph a piecewise function, absolute function or step function? Answered by Penny Nom.
	Simplify		2003-08-24
		From Jessica: I have been asked to simplify the expression (5a2)(-2b2)(3b)+(7a2)(2b2)+(-3a)(-5a)(4b) and the answer is apparently 44(a2)(b2). For the life of me I can't figure out how they derive this. Answered by Penny Nom.
	Why is 5 to the 0 power always 1?		2003-08-24
		From Crystal: Why is 5 to the 0 power always 1? Answered by Penny Nom.
	A rule with a variable		2003-08-24
		From Crystal: what is a rule with a variable Answered by Penny Nom.
	X.9999... and X+1		2003-08-23
		From David: I have read your answers to the questions on rational numbers, esp. 6.9999... = ? and still have a question: The simple algebraic stunt of converting repeating decimals to rational numbers seems to work for all numbers except X.999999.... where X is any integer. The fact that the method yields the integer X+1 in each case seems to violate the completeness axiom of the real numbers, namely that there is no space on the number line which does not have an number and conversely that every geometric point on the number line is associated with a unique real number. In the case of 3.999... for example, it seems that both the number 4 and the number 3.9999.... occupy the same point on the number line. How is this possible??? Answered by Penny Nom.
	A golf tournament		2003-08-23
		From Dale: I am running a golf tournament with twelve golfers. We will be playing four rounds of golf. I don't want to schedule the same two players together more than twice (if possible). How would I make a schedule that each player would play at least once with every other player? I would appreciate any help that you can give me. Answered by Denis Hanson.
	A worm on a hill		2003-08-21
		From Lisa and Samantha: A WORM IS AT THE BOTTOM OF A 10 FOOT HILL. HE CRAWLS UP THE HILL 4 1/2 FEET A DAY. AT NIGHT WHEN HE REST HE SLIDES DOWN 2 1/2. HOW LONG DOES IT TAKE THE WORM TO CRAWL UP THE HILL. Answered by Penny Nom.
	Two equations		2003-08-21
		From Jennifer: The following problems have me stuck and any help would be greatly appreciated seeing my text book is doing me no favours: 32a+1 - 283a + 9=0 and 52m - 5m=20 Answered by Penny Nom.
	39 consecutive natural numbers		2003-08-19
		From A student: Prove that among any 39 consecutive natural numbers it is always possible to find one whose sum of digits is divisible by 11. Answered by Penny Nom.
	The volume of a fuel tank		2003-08-16
		From Phil: I hope you can help me out with a small problem. My boat has a fuel tank measuring 1680mm long x 630mm wide x 130mm high. Can you tell me how much fuel it will hold in both litres and imperial gallons. Answered by Penny Nom.
	The number of three digit combinations		2003-08-16
		From Fred: There are four close friends having a heated discussion concerning the the number of three digit combinations using the numbers 0 through 9. The discussionÝinvolves the daily lottery.Ý Any assistance you can lend would be greatly appreciated. Answered by Penny Nom.
	Acres		2003-08-13
		From A landowner: Can you please tell me how many total acres the following measurements would equal? 280 feet by 80 feet 220 feet by 70 feet 200 feet by 75 feet Answered by Penny Nom.
	Making a blanket		2003-08-13
		From Liz: Please help me figure this out. I am making a blanket the directions call for a piece of material measuring 72"X45". Instead of one piece I'd like to make a patchwork quilt but the squares need to equal 72"X45". Centered on the bottom of the longest edge is an 18" square. Answered by Harley Weston.
	Water in a cone		2003-08-12
		From Adrienne: Water is poured into a tank in the shape of an inverted right circular cone.ð The height of the tank is 8 m and its radius at the top is 4 m. a. Draw and label a picture to represent this situation.ð (I know how to do this) b. Identify all variable quantities. (h = 8m, r = 4m) c. Find an equation that relates the variable quantities, and reduce the number of variable quantities to two. I was thinking about the equation V = 1/3 pi r2 h, which is the Volume of a cone, but I am stumped as to how I am supposed to "reduce the number of variable quantities to two." Can you point me in the right direction? Answered by Penny Nom.
	Yards and cubic feet		2003-08-11
		From Sonya: How many cubic feet are in a yard? Answered by Penny Nom.
	A sphere inscribed in a cone		2003-08-10
		From A student: A sphere with radius 5cm is inscribed in a right circular cone 20 cm in height.find (a) the base radius ,volume of the cone (b)volume of the shaded space( to 3 sig fig) Answered by Penny Nom.
	The side length of a regular octagon		2003-08-09
		From Rich: If I know the distance between the parallel lines of an octagon and want to find the length of the sides, can I just divide that distance by 2.414 to reveal the length of the sides? I work construction and just curious if I am figuring it right. Answered by Penny Nom.
	Liters in a pool		2003-08-05
		From A parent: I need to know how many litres in a 12 foot diameter, 3 foot deep pool? Any help much appreciated as I need to add the correct amount of chemicals Answered by Penny Nom.
	Diagonals in an octagon		2003-08-04
		From Amanda: How many diagonals are in an octagon??? What would be a drawing of those diagonals??? Answered by Penny Nom.
	Two precalculus problems		2003-08-04
		From Kate: Please help me verify the identity: cos2x(sec2x-1)=sin2x Also I am having trouble withdetermining whether f(x) is odd, even, or neither f(x)=x3-x Answered by Penny Nom.
	The incline of a road		2003-08-03
		From A driver: incline- % grade as to degree. ie 6% hwy grade= what degree of incline? Answered by Penny Nom.
	Percentage decrease in sales		2003-07-31
		From Linda: If I had sales in January of 2002 that were $42,493.73 and sales that were $37,281.59.Ý The difference is $5374.50.Ý What is the percentage of decrease in sales? Answered by Penny Nom.
	Inserting a comma ever three digits		2003-07-25
		From Linda: when writing a large number, why do we insert a comma every three numbers instead of every two or four numbers? Answered by Penny Nom.
	Cutting some wood		2003-07-25
		From Betty: My husband is building a six sided wood circle and would like to know the angle to cut the pieces. Answered by Penny Nom.
	The area of an odd shaped piece of property		2003-07-24
		From Barry: What is the formula for figuring the square footage of an odd shaped piece of property? Answered by Penny Nom.
	Surface area of a sphere		2003-07-23
		From Rob: I have a shere with a circumference of 12 feet. What is the total surface area of the shere in square feet and how did you find it? Answered by Penny Nom.
	nine digit numbers		2003-07-23
		From John: With a nine digit number, with each of the nine digits having a possibility of 10 different numbers then what is the total number of possible mathematical variations in the nine digit number. i.e. Social Security numbers have nine digits and if each of the nine digits have a possibility of being any one of ten numbers, i.e. 0,1,2,3,4,5,6,7,8,9. Then what is the formula to calculate the maximum possible number of variations in this nine digit number and what is the mathematical maximum possible number of variations of this nine digit number? Answered by Penny Nom.
	Natural logarithms		2003-07-22
		From Amanda: I'm going into my senior year of high school. I will be taking AP calculus, and my teacher gave us some homework over the summer. However, there are two things that I do not understand how to do. The first is, she wants us to be able to generate a unit circle by hand using 30, 60 and 90 degree triangles. I have used the unit circle in trigonometry, however I was never taught how to draw it. Secondly, I need to know how to do natural logarithms without a calculator. I was not taught how to do this, and the worksheet I was given only showed me how to complete them using a calculator. Answered by Claude Tardif.
	A pyramid with its top cut off		2003-07-21
		From David: What is the name given to a 3D shape that looks like a pyramid with its top cut off? Answered by Penny Nom.
	Slope		2003-07-20
		From Brian: You are placing a pipe 60 feet long at a slope of 1.5%. How would you figure the amount of drop from the inlet of the pipe tot he outlet of the pipe? and what is the answer . If you are trying to keep a shoulder slope of a road between 3/4'' per foot and 11/2'' per foot . If the shoulder is 10 feet wide, how would you figure how much lower should the outside of the shoulder be than the edge of pavement and what is the answer ? Answered by Penny Nom.
	|x+3| = -15x		2003-07-19
		From Nathan: Without the use of trial and error, is there a way of solving for x where |x + 3| = -15x? I know that x = -0.1875, but how do I find whether x + 3 is positive or not if I did not have this information (In other words, how would I solve whether the x-value was -3 or less, or if it was more than -3)? Answered by Claude Tardif and Penny Nom.
	"cubic feet" of a refrigerator		2003-07-16
		From Ron: Is the volume of a home appliance (e.g. fridge or freezer) calculated in a different way? I am planning to replace both my fridge and my freezer but I'm unable to determine what size replacement to get. For example, one company descibes their fridge as being 32"(L) x 30"(W) x 66" (H). I converted those measurements to feet (2.67 x 2.5 x 5.5) and I calculate the fridge to be 36.7 cubic feet. However, the company says the fridge is 18 cf. Answered by Chris Fisher.
	Cathy's Clothing		2003-07-15
		From Cathy: I am supposed to write a practical and useful word problem that would use the following algebriac inequality to solve it: 12x + 25 > 15x + 10. State the quanity that represents x and solve the inequality. Answered by Penny Nom.
	Preparing 100ml of a 30% alcohol solution		2003-07-13
		From Justin: My question is how do you prepare a 100ml of a 30% alcohol solution using 95% alcohol? Answered by Penny Nom.
	Sunshine?		2003-07-11
		From lori: It is noon, your lunch hour, but you cannot go out because there is a terrific hailstorm. Turning on your radio you hear the weathercaster predict that the hail will change to rain and that it will pour all day today. How can you determine whether the sun will be shining in 36 hours? Answered by Claude Tardif.
	A problem with lugs		2003-07-11
		From Lori: A young man's car developed a flat tire as he was driving along a deserted street. He pulled over to the curb and did all the usual things: removed the hub cap, unscrewed the lugs and rested them carefully in the hub cap, jacked up the car. As he was putting the spare tire onto the axle he accidentally kicked the hub cap. The lugs rolled out, and all five of them fell down a nearby grate. Peering through the bars of the grate the man thought that he could see the lugs about 6 feet below in a shallow water puddle. He had a problem. How do you think he solved it? Answered by Penny Nom.
	A mixture problem		2003-07-10
		From A student: Having a problem with word problems. example A chemist mixes a 10% acid solution with a 50% acid solution to form 400mL of a 40% solution. How much of each solution should be used. Answered by Penny Nom.
	A triangle in the complex plane		2003-07-10
		From Scott: The vertices O and A of an EQUILATERAL triangle OAB in the complex plane are located at the origin and 3 + 3i. Find all possible values for the complex number representing the vertex B. Give the location of B in both polar and cartesian form (to 2.d.p) Answered by Penny Nom.
	E(X + Y) and V(X + Y)		2003-07-10
		From Reuben: I'm a teacher trying to find a way to make some stats work from first principles. The topic is expectation algebra and it is for the top age level in high school. By using a set of data I can show how the mean is the same as the expected value ie 2,2,3,4,4 is 15 / 5 = 3 also, 2x0.4+3x0.2+4x0.4=3. I can also show this to work for the variance in the same style but using Sum(x-mean)2/n and the Var(X) version of squaring x then multiplying by the probability ( all this for random independant samples). Now comes the tricky bit.....when I try to show E(X+Y) = E(X) + E(Y) from setting up two data sets I get it to work only if I add each item from X to each item from Y. However, I can't get it to work for V(X+Y)=V(X) + V(Y) from two sets of data. There must be something missing in my knowledge of how the sets are required to add together or my knowledge of expectation algebra. I am familiar with proofs but still want to show my students that the basic formulae work from groups of data whether done the long way or by use of formulae. Can you help please? Answered by Penny Nom.
	An onsale DVD player		2003-07-09
		From Kim: I have a DVD player with a regular selling price of $175 and percentage of discount is 10 percent. How to solve for discount amount and sale price? Also, when you figure out the sale price how to figure out commission amount when percentage of commission is 5 percent? Answered by Penny Nom.
	A wooden deck around a pool		2003-07-09
		From Dat: A pond is enclosed by a wooden deck that is 3 feet wide. The fence surrounding the deck is 100 feet long. If the pond is square, what are its dimensions? If the pond is rectangular and the length of the is three times its width, what are the dimensions of the pond? If the pond is circular, what is the diameter of the pond? Which pond has the most area? Answered by Penny Nom.
	Two cars		2003-07-09
		From Nicole: Two cars start off at the same point on a striaght highway facing opposite directions. Each car drives 6 miles, talkes a left turn, and drives for 8 miles. How far apart are the two cars. Answered by Penny Nom.
	Is 3/5 CLOSEST to 0, 1/2 or 1?		2003-07-09
		From A student: I would like to know is 3/5 CLOSEST to 0, 1/2 or 1. And can 3/10 go either way as to be closest to 0 or 1/2. Answered by Penny Nom.
	A geometry problem		2003-07-08
		From Chris: My name is Chris, I work for a custom fabricator company. I am needing a formula for the Height (H) shown in the attached picture. The picture shows dimensions for my current application. If you could please, assign variables to the dimensions. Answered by Harley Weston.
	Volume of water in a pool		2003-07-06
		From An other: How many litres of water are in a pool that is 16 feet in diameter and 35 inches deep? Answered by Penny Nom.
	The length of fabric in a roll		2003-07-03
		From Paul: We receive rolled fabric as part of our process and I would like to know is there a formula that could be used to estimate the overall length of the roll with out rolling the fabric out and measuring its length. Answered by Harley Weston.
	Contradiction in the Procedural Precedence and the Distributive property		2003-07-03
		From Arthur: When complicated expressions exist on both sides of a fraction, and both these expressions contain like and unlike terms with "literal" coefficients, the procedural precedence suddenly gets extremely confusing and seems impossible to simplify. This seems confusing and impossible to simplify because there is a HUGE contradiction in the way Procedural Precedence and the Distributive property deal with Parentheses. The Procedure says you MUST deal with what's INSIDE the parenthesis FIRST, BEFORE dealing with ANYTHING on the outside where as the Distributive property contradicts that by saying to go ahead and ignore the Precedence and use a factor on the outside of the Parenthesis. Answered by Claude Tardif.
	C is 10 more then the square of...		2003-07-03
		From Carolina: C is 10 more then the square of the quotient of the sum of x and y , and the product of x and y. Which equation expresses this relationship? A. C=(x+y +10)^2 ___ xy B. C=(x+y)^2 + 10 ___ xy C. C=(xy)^2+10 ___ x+y D. C=(x+y)^2 + 10 ___ xy Answered by Penny Nom.
	The domain of 1/g(x) - 5		2003-07-03
		From Barbara: If the range of g(x) is ( neg. infinity,4] and the domain of g(x) is ( neg. infinity, infinity), how do I find the domain of 1/g(x) - 5? Answered by Penny Nom.
	How much soil will be removed?		2003-07-02
		From Amy: My site is 1230' (east-west) by 1300' (north-south) and we need to remove 2 feet of soil from the entire site, how much soil will be removed? Answered by Penny Nom.
	Setting up a word problem		2003-06-30
		From Christie: A rectangular corral is forty feet longer than it is wide. If the perimeter is 220 feet, determine the length and width of the corral. Answered by Penny Nom.
	A ruler and compass construction		2003-06-29
		From Mandy: I have been searching for instructions on how to do this using a compass. Can you please send instructions step by step on how to bisect a segment into any given number of segments. (example, a way that it will work for bisecting segment into 3, 4, or even 5 congruent parts) Answered by Penny Nom.
	Solve x = y^z for z		2003-06-28
		From Nathan: If x = y^z is there a way to solve for z, if x and y are given, without guessing or already knowing the answer? ie: 64 = 2^z 6 is the obvious value for z. Is there a way I could solve for this variable using a formula, which would also apply when more complex values were substituted for x and y? Answered by Penny Nom.
	Polynomials degree 4 and bigger		2003-06-26
		From Stephen: How do I show kids how to find all the zeros for polynomials degree 4 and bigger. For examples: r(x) = x5-11x3-7x2+77 = (x2-11)(x3-7) and s(x) = x4-121 = (x2-11)(x2+11) Also am I correct when I say that the following are irreducible? f(x) = x2-11 g(x) = x3-7 h(x) = x4-5 Answered by Harley Weston.
	Odd powers of sine and cosine		2003-06-25
		From Antonio: Can you please tell me how to integrate a trig function involving sine and cosine? I know if the powers of both the sine and cosine are even and nonnegative, then I can make repeated use of the power-reducing formulas. But for the question I have on my hand, the powers of both sine and cosine are odd: ( sin3x + cos7x ) dx. Answered by Harley Weston.
	Sesame Street on Stage		2003-06-25
		From Christie: Sesame Street on Stage has different ticket prices for adults and for children under 6. Beth and her two children, ages 3 and 4, paid $15 to gain entrance, while Jamie and John Jacobs and their 2-year old daughter got in for $19.50. What is the ticket price for adults? Answered by Penny Nom.
	4-3(m+1)=(-38)		2003-06-25
		From Jamie: I have a problem, like most of your mailers, I do remember BEDMAS but maybe I'm missing the finer points! It's been a while, he goes 4-3(m+1)=(-38) Answered by Penny Nom.
	Interest compounded daily		2003-06-24
		From Jeff: What would be the amount of interest charged or accrued and how is it calculated on principal balance of $209.12 @ 6% interest rate compounded daily for 70 days? Answered by Penny Nom.
	pst and gst		2003-06-24
		From Robin: I need to find an easy solution to remembering how to calculated the gst and pst once I have the total amount. ex: my total is $154.40, I have to find the gst and then the pst. I live in bc so the taxes are 7% for gst and 7.5% for pst. Answered by Penny Nom.
	Flim		2003-06-24
		From Dan: I have a 4th grader and the word (Flims) came up in her summer text, Answered by Penny Nom.
	An inch and a millimeter		2003-06-21
		From Greg: The conversion factor for inches to millimeters 25.4 It strikes me as very odd that it's not some infinite decimal. I could understand this if one system was derived from the other but as I understand it they were derived independently. Is the conversion 25.4 or 25.4000XXXXXXX? If it's just 25.4 then how did that happen? Answered by Harley Weston.
	Numbers John likes		2003-06-20
		From Steve: John likes 400 but not 300; he likes 100 but not 99; he likes 2500 but not 2400. Which does he like? 900 1000 1100 1200 Answered by Penny Nom.
	The sum of two numbers is 5 and their difference is		2003-06-16
		From Akhil: The sum of two numbers is 5 and their difference is 11. What is the product of the two numbers? Answered by Penny Nom.
	A 40% markup		2003-06-12
		From Nick: I am attempting to determine the Retail price of an item that costs me 11.00. Our company wants to sell it at a markup of 40%. I calculated this two ways, first the way I thought it should be done. Second, the way the calculator does it (and my accountant). Cost + Cost*(percentmarkup/100)= retail price 11.00 + 11.00*.40 = retail price 11.00 + 4.40 = 15.40 retail price Using the calculators Mark Up key the answer is 18.33. Or 7.33 more than the cost or 67%. I am confused by this Mark Up key and how it calculates. I used a cost of $10.00 and marked it up 50%. I thought it should equal $15.00 but the calculator says $20.00? This seems to be 100% markup, yes? Can you explain the difference between the way I did it and the way a Business calculator does it? Answered by Penny Nom.
	A project about crosses		2003-06-10
		From Joel: I have this project to do about crosses and I can't think of what the answer is for the following questions: What is the area rule of the crosses (the table below will help you)? Cross Number Area sq cm 1 5 2 13 3 25 4 41 5 61 I also need to know what the formula is for it? Answered by Penny Nom.
	Teaching second grade		2003-06-10
		From A teacher: I am going to be teaching second grade next year. How can I differentiate instruction in mathematics to meet the needs of all of my students, from those who need intervention to those who need challenges? What are some techniques I can try for this grade level? Answered by Diane Hanson.
	Two trig problems		2003-06-10
		From Bett: I have this ongoing trouble with trig and solving triangles with laws of cosines and sines!! For example if it asks to solve triangle FGH, given angle G=102.7 , side f=14.2, and h=18.6. Now do I use law of cosines because I don't have the measure of an angle and length of the opposite side??I don't know where to go from here,I am totally confused!!! I also have a problem with this word problem I have been doing. It asks: An airplane flies 847.5 km at a bearing of 237.3 degrees. How far south and west fo its original position is it? Huh? Please help! Answered by Penny Nom.
	How many gallons are in 83 liters?		2003-06-09
		From Anita: How many gallons are in 83 liters? Answered by Penny Nom.
	Definitions and descriptions		2003-06-08
		From Tammy: MY DAUGHTERS TEACHER ASKED HER TO GIVE BOTH A DESCRIPTION AND A DEFINITION OF THE FOLLOWING ... CIRCLE, SQUARE, TRIANGLE,HEXAGON...... THE LIST GOES ON. WHAT IS THE DIFFERENCE BETWEEN DEFINITION AND DESCRIPTION ? DO A CIRCLE FOR AN EXAMPLE PLEASE. Answered by Penny Nom.
	The metric and Imperial systems		2003-06-08
		From Ashlee: i am a year 8 student, and i am doing my Maths talent quest on the Metric and Imperial number system. i was wondering, where did the 2 systems orginate and if possible, a little bit or information. I also need to know the conversions of ounce, foot, mile..etc..from imperial to metric. Answered by Penny Nom.
	A radio controled car		2003-06-08
		From Robert: I have a radio controled car (scale size 1/43). This car can travel 490 ft. per minute. I would like to know how fast that is at that scale size in miles per hour (and Kilometers per hour)? Answered by Penny Nom.
	Spacing the spindles for a railing		2003-06-06
		From Jennifer: Scott is a homebuilder. He builds railings in which he places spindles. Spindles ar evertical posts taht are equally spaced beneath a horizontal bar. Scott would like a mathematical model to help him determine the amount of space to put between each spindle. The railing must follow the following criteria: The spaces between each spindle must be equal except for the ones at either end. Theses spaces are smaller. They are half the width of a spindle less than the other spaces. The number of spindles needs to be minimized since spindles are costly. Help Scott determine what width of space to use between the spindles. Create a mathematical model to determine the width of space between each spindle in termso f the number of spindles. Use an 8' (96") railing that has 2 1/2" wide spindles. Explain your thinking. For safety reasons the maximum width of a space is 4" Generalize you model to determine the width of spaces for total railing of length L and spindle width s Answered by Penny Nom.
	The square footage of a section of land		2003-06-04
		From Diane: We are trying to calculate the square footage of a section of land with the following dimensions: One end is 100 feet. The other end is 105 feet.. One side is 350 feet and the other side is 372 feet. I calculated the area as 35,875 sq. feet, however, the brochure for the land says the area is 36,200 + sq. feet. Answered by Leeanne Boehm.
	$22,534.56 is what percent of $27,820.00?		2003-06-04
		From Minnie: $22,534.56 is what percent of $27,820.00? Answered by Penny Nom.
	BEDMAS		2003-05-31
		From Kristie: (3x50)+20/5=? I know bedmas but i forget how to do it. Answered by Penny Nom.
	$1/week for week 1 and then double each week		2003-05-28
		From A student: I AM DOING A PROJECT FOR MATH I AM TRYING TO CREATE A SEQUENCE BASED ON: MAKING A SALARY OF $1/WK FOR THE FIRST WEEK WITH IT DOUBLING EVERY WEEK FOR 52 WEEKS, SO MY SEQUENCE LOOKS LIKE THIS: 1,2,4,8,16,32,64,128,256,512,1024 ETC. THERE WOULD BE 52#'s TOTAL IN MY SEQUENCE.I BELIEVE IT IS CALLED A FINITE SEQUENCE. MY QUESTION IS HOW DO I CREATE A FORMULA/RULE FOR THIS PARTICULAR SEQUENCE? MY GOAL BEING TO FIND THE 52nd TERM IN THE SEQUENCE. Answered by Penny Nom.
	5 to the power n		2003-05-28
		From Sam: What is the integer n for which 5 to the n power + 5 to the n power + 5 to the n power + 5 to the n power + 5 to the n power = 5 to the 25th power? Answered by Penny Nom.
	Millimeters to inches		2003-05-28
		From Brian: I am a music instructor just trying to get a horn repaired. I have been trying to get replacement pearls for a keyboard of a horn. The mechanic needs the measurement in inches. The calibers say that the size is .115 mm can you tell me what that is in inches, I tried your formula of 2.54 mm per inch but this is a smaller size and I cannot seem to figure it out. Answered by Penny Nom.
	George and his goat herd		2003-05-27
		From A student: George the bulgarian goatherd drives his father's goats into a valley each morning and lets them browse there all day before driving them home in the evening. he notices that each morning the goats immediately separate into groups and begin to feed the number and sizes of the initial groups vary some days there are nine and so days there are three or fewer. there can be groups of one or the whole group. about every five minites one goat breaks away from each feeding group and these breakaway goats form into a new group. George has noticed that by the afternoon, even though the goats continue their regrouping the sizes of the groups have stabilised, and there is always seven feeding groups. How many goats are there in the herd? What are the sizes of the feeding groups once they have stabilised? Answered by Penny Nom.
	Two sequences that agree in the first 4 terms		2003-05-26
		From A student: Is it possible to have two formulas that define sequences that agree on the first four terms but not the rest? Answered by Penny Nom.
	The cross-section of a football field		2003-05-25
		From Francis: Have you ever walked on a football field covered with artificial turf? If so, you probably noticed that the field is not flat. The profile of the surface is arched and highest in the centre, permitting rainwater to drain away quickly. height from base to highest point- 45.75 centimetres distance of the field- 50 metres a) The diagram shows the profile of an actual field, viewed from the end of the field. Assuming that the cross-section is a parabola, find the algebraic model that describes this shape. b) Use your equation to determine the distance from the sidelines where the field surface is 20 cm above the base line. Answered by Harley Weston.
	Two piles of cards		2003-05-24
		From Sam: A standard deck of 52 cards (26 red, 26 black) is separated into two piles, not necessarily equal in size. The first pile contains seven times as many black cards as red cards. The second pile contains a number of red cards that is a multiple of the number of black cards in that pile. How many red cards are in the first pile? Answered by Penny Nom.
	An array of pennies		2003-05-23
		From Saundra: If you have 100 pennies and you are suppose to make an array do you arrange the pennies by date? Answered by Penny Nom.
	The weight of a fish tank		2003-05-20
		From A ponderer: I had a question pertaining conversion units..I have a fish tank at home and the dimensions are 24, 44, and 48 inches, I want to find out how much it weighs in pounds when filled up with water...knowing water is 62.4 pounds per cubic feet...do I just divide the 62.4 pounds to 12 because I"m trying to find out through cubic inches. Answered by Penny Nom.
	The HCF and LCM of polynomials		2003-05-20
		From Charanpal: Question: Find the HCF and LCM of the polynomials given below. Verify that he productof these HCF and LCM differs from the product of the polynomials, if at all, by a factor of -1 1-x2 and x3 -1 1 - x2 and x4 - 1 Answered by Penny Nom.
	A trig identity		2003-05-20
		From Patty: Please help with the following 1/ tanx + cotx = sinxcosx Answered by Penny Nom.
	R= 5.3lnx + x.		2003-05-11
		From A student: Reaction R to a dose x is given by: R= 5.3lnx + x. For a certain drug, R must not exceed 21. Show that a dose between 8 and 12 units satisfies this requirement & find, correct to 5 decimal places, the greates value of x which satisfies this condition? Answered by Harley Weston.
	Subtracting rational expressions		2003-05-10
		From Simone: hi, i'm totally lost. i understand that you need to find a lowest common denominator to subtract two fractions (rational expressions) with different denominators. but what if the denominators are "x-1" and "x". is x the common denominator? if so what happens to the "-1"? do you know of any live online help i can get with the following: 3/(x-1) - (1-2x)/x i've looked through my notes and have no examples that quite match that i can follow to get through it. please help! Answered by Penny Nom.
	x-6square root of x +8=0		2003-05-10
		From Elizabeth: x-6square root of x +8=0 Answered by Penny Nom.
	Circumference		2003-05-09
		From A parent: Find the circumference use 3 1/7 for pi 1. r= 28 ft. 2. D=98 cm Answered by Penny Nom.
	Real numbers		2003-05-09
		From Sirena: what is a "real" number Answered by Penny Nom.
	sin theta = 7/8		2003-05-07
		From Patty: If sin0 = 7/8 and 0 is in quadrant 2, find the other five trigonometric functions of 0. (report your answers in radical form) Answered by Penny Nom.
	ABCD*4 = DCBA		2003-05-07
		From Dee: In the following problem, if the letters A, B, C and D represent some number, what numbers would they represent so that: ABCD*4 = DCBA Answered by Penny Nom.
	2/sqrt(2)		2003-05-07
		From Mike: I was looking at an example of csc 45 deg where csc = hyp / opp = 1 / (sqrt(2) / 2) = 2 / sqrt(2) = sqrt(2) I just don't get this. If sqrt(2) = 1.4142145..... How can 2 / sqrt(2) = sqrt(2) as the example shows? Answered by Penny Nom.
	Rules of exponents		2003-05-05
		From Carl: Hi, I am a student who would like to recall how to multiply exponents. Here is such an equation: 6.02569 X 1025 X 5.254 =? Also, adding exponents. Don't I just add subtract the exponents separately? Such as 523 +15-12 =?? Answered by Penny Nom.
	Write sin(3x) in terms of sin(x)		2003-05-05
		From A student: Write sin 2x in terms of sin x Answered by Penny Nom.
	Four digit palindromes		2003-05-05
		From Heather: How many palindromes were in between the numbers 1000 and 9999? Answered by Penny Nom.
	Integrating e^x sin(x)		2003-05-03
		From Lech: I am having trouble integrating the following expression by parts: ex sin(x) I used the integrator at http://www.integrals.com/ to find the solution, ? 1/2 ex cos(x) + 1/2 ex sin(x). This is easy to confirm by differentiation, however I am confounded as how to arrive at the answer. Answered by Penny Nom and Claude Tardif.
	The volume of air flowing in windpipes		2003-05-02
		From James: The volume of air flowing in windpipes is given by V=kpR4, where k is a constant, p is the pressure difference at each end, R is the radius. The radius will decrease with increased pressure, according to the formula: Ro - R = cp, where Ro is the windpipe radius when p=0 & c is a positive constant. R is restricted such that: 0 < 0.5*Ro < R < Ro, find the factor by which the radius of the windpipe contracts to give maximum flow? Answered by Penny Nom.
	positive multiples of 10 that are the sum of four consecutive integers		2003-05-01
		From Taurus: How many positive multiples of 10 that are less than 1000 are the sum of four consecutive integers? Answered by Penny Nom.
	A circle, tangent to two circles and a line		2003-04-30
		From Keith: I have a horizontal line (that is treated as a datum line or the X axis), with two circles having their center points at different heights from that line (X1,Y1 & X2,Y2). The two circles are also at different diameters (R1 & R2). Both circles and the line (X-Axis) do not intersect nor are they tangent. My goal is to determine the maximum diameter of an inscribed circle that will fit between all three. Answered by Chris Fisher and Harley Weston.
	A binomial probability		2003-04-30
		From Erica: In a biathlon, athletes shot at 20 targets. A particular athlete had a probability of 0.18 of missing a target. Assuming a binomial distribution, what is the probability, to the nearest thousandth, that the athlete hit exactly 16 targets? Answered by Andrei Volodin.
	Some shapes		2003-04-29
		From Suzanne: What shape has 12 edges all the same length? What shape has 3 surfaces and 1 is curved? Answered by Penny Nom.
	Profit for a dance studio		2003-04-28
		From Craig: A dance studio charges $80 per student for a series of 2 hour lessons. The studio's costs are $30 per hour for the instructor, $15 per lesson for the room rental, and $3 per student for miscellaneous expenses. If x is the number of students enrolled in the class, express the studio's profit P(x) in terms of x. Find the profit if 10 students are enrolled in the class. Answered by Penny Nom.
	A skill testing question		2003-04-27
		From Allan: it is a contest Labatt Blue can you please give me the answer some people are saying 154 and some 34 Answered by Leeanne Boehm and Harley Weston.
	20% of 40% of 500		2003-04-27
		From A student: What is 20% of 40% of 500 Answered by Penny Nom.
	The product of four consecutive integers is 3024.		2003-04-25
		From pillar: The product of four consecutive integers is 3024. What are those numbers. Answered by Penny Nom.
	Gallons of rain		2003-04-25
		From Jocelyn: If you have a surface of 6500 square feet and 1 inch of rain falls on the surface, how many gallons of water does this equal? Answered by Penny Nom.
	38 minus 10 plus 12 divided by 4 times 16		2003-04-23
		From James: please help me work this math problem 38 minus 10 plus 12 divided by 4 times 16 Answered by Harley Weston.
	Hidden by the curvature of the Earth		2003-04-23
		From Shirley: There are 2 six foot men. What would the distance be between them before one could not be seen because of the curvature of the earth? Answered by Penny Nom.
	Two intersecting graphs		2003-04-23
		From Patty: a) graph the equation x2 - y - 4 = 0 x2 + y2 = 9 on the same set of coordinate axes. I did not have a problem with this. The problem is part (b) of the question ask: Find all solutions of the system in part (a) algebraically. Express answers in decimal form, accurate to two decimal places. Answered by Penny Nom.
	8 faces, 12 vertices, and 18 edges		2003-04-22
		From Thomas: I would like to know the proper name for this geometrical solid. It has 8 faces, 12 vertices, and 18 edges? Answered by Penny Nom.
	One one		2003-04-22
		From Brad: find the next two rows of numbers? 1 1 1 2 1 1 1 1 2 3 1 1 2 1 1 1 2 1 3 Answered by Leeanne Boehm.
	The effectiveness of a drug		2003-04-22
		From A student: A certain drug is found to be effective 80% of the time. Find the probability of successful treatment in two out of four cases. Answered by Andrei Volodin.
	Manipulating exponents		2003-04-21
		From Denita: Rewrite using only positive exponents: (4a^4b^2)^4 * (4a^ -3 bc^2)^ -3 Answered by Harley Weston.
	Chopping trees		2003-04-19
		From Tamara: The master needs some of the trees (twenty, to be exact) at the back of his spooky old mansion cleared to make way for a new evil laboratory, so he decides to send some his slaves to do the work for him. He initially sends out four of his men, armed with axes, to chop the trees down. Due to the fact he is very impatient, every ten minutes he sends out another man to help with the work. Assuming that it takes one man 30 minutes to chop down 1/3 of a tree, how long till all twenty trees are chopped down? Answered by Penny Nom.
	A tangent to a circle		2003-04-18
		From Lech: The line with equation y=mx is a tangent to the circle with equation x2+y2-6x-6y+17=0. Find the possible values of m. Answered by Harley Weston.
	Interest compounded daily		2003-04-18
		From Bruce: I recently received $7,987.68. This amount consisted of $7,543.61 invested at 6% per annum, compounded daily. I am trying to find out how many days this investment accrued interest. Answered by Penny Nom.
	The substitution method		2003-04-14
		From Patty: I need help with the following: 5x - 4y = 13 2y + 3x = -1 Answered by Penny Nom.
	The square of my age was the same as the year		2003-04-14
		From Pat: Augustus de Morgan wrote in 1864, "At some point in my life, the square of my age was the same as the year." When was he born? Answered by Penny Nom.
	Area of a trapezoid		2003-04-13
		From A road builder: My husband works with asphalt building roads. There are times when one end of the road will be (for example) 100ft wide the other end would be( for example) 200ft wide and he must figure the area in square feet. So far it has been a guessing game because he dosen't have the formula to figure the square feet. Answered by Penny Nom.
	Incremental standard deviation		2003-04-12
		From Carlos: I need to calculate the standard deviation for a group of data, but I don't know in advance what is the mean. Is there a way to adjust the STDV for each datum without keeping all of the previous values? This is needed basicaly for performance, so I won't need to read twice the same data (spend processing time) nor save the previous values (spend memory). Answered by Andrei Volodin and Penny Nom.
	A fractional inequality		2003-04-08
		From Jessica: Solve for x. Write in interval notation. [(x2)-9]/[x-5] >= 0 Answered by Penny Nom.
	The surface area of a cube		2003-04-07
		From Sarah: if the volume of a cube is 64 cm, then what's the total surface area? I also want to know how to show my work. Answered by Penny Nom.
	Jo's books		2003-04-07
		From Miguel: Jo announces, "I have more than 999 books." Jean says: "No Jo! You have fewer than 1,000 books." Mary says: "Jo has at least 1 book." Only one of these statements is true. How many books does Jo own? Answered by Penny Nom.
	The area of a parallelogram		2003-04-06
		From A student: Find the area of the parallelogram with vertices (0,0),(7,2),(10,7),(3,5) Answered by Penny Nom.
	The height of an equilateral triangle		2003-04-06
		From Rosa: If Each side of an equilateral triangle is 10 m. What is the height? Answered by Penny Nom.
	How many hits?		2003-04-06
		From Jack: My name is Jack. I'm a uncle. Student is in the 5th grade email is above. If a baseball player at sping training had a good season with the following: one seventh of his hits were doubles. 12.5% of his hits were home runs. But didn't have any triples. How many hits did he have? Can you give me an explanation of you solved the problem. Answered by Penny Nom.
	Divide a circle in 8 equal pieces		2003-04-04
		From Naomi: I have to divide a circle in 8 equal pieces but can only cut 3 times can you please help me Answered by Penny Nom.
	Uses of conic sections		2003-04-01
		From William: My name is William and I am doing a research paper on conic sections for my 12th grade math class. Part of the project is to find two conic sections in our world today and explain what there purpose is. I really need help in this area because I've been searching the internet for where conic sections are used in our world today and I really can't find anything. If you can tell me specific building or a pyramid that contains conic sections that would be great. Or even something in the universe would be helpful. Answered by Leeanne Boehm.
	Doubling the size of an object		2003-04-01
		From Dave: If I have a known surface area and volume of an unknown object and I want to double the size of the object, how do I find the new area and volume? Answered by Walter Whiteley.
	A handshake problem		2003-03-31
		From Jaylan: Suppose you and your partner attend a party with n other couples. Several handshakes took place. No one shook hands with himself (or herself) or with their partner, and no one shook hands with the same person more than once. After all the handshaking was completed, suppose you asked each person, including your partner, how many hands they had shaken. Each person gave a different answer. Determine how many hands did you shake and how many hands did your partner shake when n=5 Answered by Penny Nom.
	Quadratic word problems		2003-03-30
		From A student: Question: i think i know the basics of how to solve direct quadratic equations,but how do i go about solving those word problems? i have tried them times and again, but nothing seems to work at all!they are driving me crazy! pls help!:):):):):) bob & nick earned $1260 each. bob's hourly wage is $3 more than nick's hourly wage. he worked 2h less compared to nick. find the number of hours nick worked. there are 2 tanks in henry's house. in tank A, the fish are all goldfish. they are bought at a total cost of $259. in tank B, there are only guppies. the guppies were bought at a cost of $1.20 each. a day later,henry bought 3 more goldfish and put them into tank A. the number of guppies in tank B is now twice the number of goldfish in tank A.the total cost of all the fish that henry has presently,i.e. goldfish & guppies, is $355.30. given that the cost of each goldfish is the same, a)find the initial number of goldfish in tank A b)find the total cost of all the guppies. a particular disc can be made to rotate at 2 different speeds. if it is made to rotate slower by 135 revolutions per hour, it wld require an additional 2.7 hour to make 315 revolutions. find the higher speed at which it can operate. Answered by Penny Nom.
	12*nC2 = n!		2003-03-30
		From A tutor: Solve for "N" 12*nC2=N! Answered by Walter Whiteley.
	The vertex of a cone		2003-03-27
		From Holly: I read your response to Callie about whether a cone has a vertex or not. Is it ONLY a vertex if both halves of the cone are together or can one half of the illustration have a vertex? Answered by Walter Whiteley.
	Can twice a square be a square?		2003-03-25
		From Mike: The other day it occurred to some students that they could think of no square number which is an integer, which can be divided into two equal square numbers which are intergers, Or put another way, no squared integer when doubled can equal another square integer. For example 5 squared plus 5 squared is 50, but 50 is not a square number. Answered by Walter Whiteley and Claude Tardif.
	A royal flush		2003-03-24
		From Vikki: A poker hand consists of 5 cards selected randomly from an ordinary deck of cards: find the probability of a ROYAL FLUSH : the 10 , jack, queen,king and ace of the same suit. I was thinking somewhere along the lines of: *the number of ways to get the suit is 4C1 *the number of ways to get a 10 out of the 13 cards etc.... ...but Im not sure I am going about this the right way, could you help? Answered by Andrei Volodin.
	Friends and enemies		2003-03-24
		From Becky: Consider a room that contains six people. Any two people are either friends of each other, or they are enemies. A. Argue why there are three people, all who are friends, or there are at least three people, all who are enemies B. Rephrase the situation using graph terminology, using all of these terms correctly: vertex, edge, graph, complement, clique, independent set, and bipartite. Answered by Penny Nom.
	A triangle and a circle		2003-03-21
		From Jynks: We need a formula that we can use to figure this out for work. We aren't math wiz's or students. Basically we know 3 points in space of a triangle, we know the length of each side and the length of the line from apex to base line. Each point of the base line ends upon the circumference of a circle. IS three a way to work out the radius of that circle. Answered by Penny Nom.
	Scientific notation		2003-03-20
		From A student: what is one millionth times one thousand in scientific notation. Answered by Penny Nom.
	Gallons in a tank		2003-03-20
		From Leslie: I am trying to figure the liquid gallons in a water tank that is 19" wide by 29.25" long and is 12.25" high. Could you tell me the formula to figure this out. Answered by Penny Nom.
	Harmonic numbers		2003-03-19
		From Becky: Harmonic numbers are Hn = 1 + ? + 1/3 + . . . + 1/n Use induction to prove the following theorem: For all natural numbers n, H1 + H2 + . . . + Hn = (1+n)Hn - n Answered by Penny Nom.
	A recurrence relation		2003-03-19
		From Becky: Solve this recurrence relation, with the initial conditions. A1 = 10 A2 = 100 An = 10a n-1 + 29a n-2 Answered by Penny Nom.
	The origin of integers		2003-03-19
		From Travis: What are the real life usages of integers? Also what is the origin of integers? Answered by Harley Weston.
	1 followed by a million zeros		2003-03-19
		From David: What do you call the number represented by the numeral '1' followed by one million zeros? Answered by Penny Nom.
	Two algebra problems		2003-03-18
		From Kayla: 1st question- If a+b divided by a equals 6 and b+c divided by c equals 9, compute the numerical value of a divided by c. ( Your answer will be mumbers only, no variables.) 2nd question- Three adjacent faces of a box (a rectangular prism) have areas of 7, 14, and 18 square inches. Find the volume of the box. (Hint: Choose variables to represent the three sides of the box and then figure out the problem.) Answered by Peny Nom.
	Three proffs of a trig identity		2003-03-18
		From Nadene: Prove the identity. cos [x + (y-pi/2)] = sin (x+y) A hint was also provided which is: "Apply cos (alpha + beta) first then within that apply cose (alpha-beta)" Answered by Penny Nom.
	An equilateral triangle		2003-03-17
		From Shirley: An equilateral triangle is one in which all three sides are of equal length. If two vertices of an equilateral triangle are (0,4) and (0,0), find the third vertex. How many of these triangles are possible? Answered by Penny Nom.
	A sequence that converges to e		2003-03-16
		From Dane: Something I noticed fooling around with a calculator about 30 years ago. Considering e = 2.718281828459045.... Using Window's Calculator you will find 1.111 = 2.8531167... 1.01101 = 2.731861... 1.0011001 = 2.71964085... 1.000110001 = 2.71841774... 1.00001100001 = 2.7182954... 1.00000110000011 = 2.178231875... 1.000000110000001 = 2.178219643... There apears to be a pattern. My conjecture is: 1.'infinite number of zeros'11'infinite number of zeros'1 = e. Answered by Penny Nom.
	Runs		2003-03-16
		From Diana: How many arrangements are there with n 0's and m 1's, with k runs of 0's? (A run is a consecutive set [1 or more] of the same digit; eg. 000 111 0 11 00 has three runs.) Answered by Penny Nom.
	Distributing r identical balls into n distinct boxes		2003-03-16
		From Diana: How many ways to distribute r identical balls into n distinct boxes with exactly m boxes empty? Answered by Penny Nom.
	Working backwards		2003-03-14
		From Melody: Triva went to the ardcade at the state fair to win some goldfish. She already had some goldfish at home, but wanted more. She won enough goldfish to double her stock. Her mom made her give four away. She put her new ones in the tank with the others, by the morning half of the goldfish had died. Triva's friend gave her six more. The next morning two-thirds of her goldfish died. She was left with two goldfish after giving one to a friend. How many goldfish did she start with? Answered by Penny Nom.
	1575		2003-03-13
		From Sharyn: find 6 integers that when multiplied with each other equal +1575 and when the same integers are added together equal zero. there are more positives than negatives and one of the numbers is a double digit between 10 and 20 Answered by Penny Nom.
	An arc of a circle		2003-03-12
		From Melissa: A strip of wood is 16 ft. long and is bent in the arc of a circle. Two radii, from the center of the circle to the ends of the arc, form a right angle. What is the approximate distance from one end of the wooden arc to the other? Answered by Penny Nom.
	Harmonic numbers		2003-03-12
		From Becky: What can you tell me about the limit of harmonic numbers as it reaches infinity? Answered by Penny Nom.
	Monomials		2003-03-11
		From Roxy: Explain why (x+y)z is not equal to xz+yz? P.S. Z is an exponent Answered by Penny Nom.
	Surface area of a sphere		2003-03-11
		From Kim: a sphere has a surface area of 128 pi sq. units. What is its exact radius? formula is 4 pi r2 I believe but how do I get radius Answered by Penny Nom.
	Division names		2003-03-10
		From A parent: what is the answer to a division problem called Answered by Penny Nom.
	Three digit number		2003-03-10
		From Grace: What three digit positive integer is exactly 32 times the sum of its digits? Answered by Claude Tardif.
	A question on combinations		2003-03-06
		From Jose: I'm an architect student and have a question on combinations. I have a grid of 3 x 3, hence a total of 9 spaces. I have 3 elements to place in this grid. How many possible ways are there of arranging this elements on this grid ? (order, orientation not important) First putting the elements each in its own space and secondly allowing the elements at a given moment to "share" one space. Since I got kind of obsessed with this I went ahead and graphically did all the combinations allowing "sharing", a grand total of 729. How could I have known this before hand ? Answered by Penny Nom and Claude Tardif.
	Mary typed a six digit number		2003-03-06
		From Pillar: Mary typed a six digit number, but the two 1's did not show. What appeared instead was 2002. How many different six-digit numbers could she have typed? Answered by Penny Nom.
	(n+17)(n+7) = 0		2003-03-05
		From Janea: What is the answer to 1. (n+17)(n+7)=0 What is the answer to:2. (y-15)(y-100)=0 Answered by Penny Nom.
	Can a square be a rhombus?		2003-03-04
		From Beth: Can a square be a rhombus? Some sources say yes, some say no. Some sources define a rhombus as a quadrilateral and parallelogram with equal sides, but without right angles. Some sources say a square is a special case of a rhombus. Clarity, please! Answered by Walter Whiteley.
	y < 2x + 1		2003-03-01
		From Erika: how can I solve and graph y<2x+1 and which side in the graph should i shade after i finish solving my inequality? Answered by Penny Nom.
	Finding the area when the perimeter is known		2003-02-28
		From Yvette: What is the size of an area in sqare feet when the perimeter totals 842 feet. Sides are 190ft+180ft+200ft+54ft+118ft+100ft. Answered by Penny Nom.
	______cm=0.048km		2003-02-27
		From Antonette: ______cm=0.048km Answered by Penny Nom.
	Can a square be considered a rectangle?		2003-02-27
		From Carla: Can a square be considered a rectangle? (since opposite sides are same length and parallel) Would a regular hexagon or octagon be considered a parallelogram since its opposite sides are parallel? or does a parallelogram HAVE to have only 4 sides? Answered by Penny Nom.
	A number line		2003-02-27
		From Shery: My seventh grader problem of the month 0__________1______________5____> This is a arrow, the number should be below A.Mrs Decker created an arrow representing a number line shown above. She wanted to find points and label them with a heart (G) for Valentine's Day so that the fraction 5/g is less than 1. (be sure to mark the G and not the fraction 5/g). She pondered, "Are there any other locations for G?" Is so help her description the location of all these points. If not why not? Answered by Penny Nom.
	A regular polygon		2003-02-26
		From Melissa: The measure of each interior angle of a regular polygon is eight times that of an exterior angle of the polygon. How many sides does the polygon have? Answered by Penny Nom.
	X times Y equals ten million		2003-02-26
		From Baneen: Would you be able to tell me which two numbers would compute ten million without any number having zeros in it? Answered by Penny Nom.
	(xy)z = 64		2003-02-26
		From Melissa: How many ordered triples of positive intergers (xyz) satisfy (x[raised to the y])raised to the z = 64? Answered by Penny Nom.
	A section of land		2003-02-25
		From Bev: How many acres in a section of land? How many square miles is in a secion of land? Answered by Penny Nom.
	The length of an arc		2003-02-24
		From Gavin: does anyone have a formula for calculating the length of an arc if I have the circle radius and the cord length of the arc?? Answered by Penny Nom.
	Excluded values		2003-02-22
		From Josh: Why do you think it is necessary to include the "excluded values" when you write your answers to rational expressions? Answered by Penny Nom.
	A trig identity		2003-02-22
		From Ron: We have spent hours trying to solve the following identity without success. Can you give us some hints as to how it is done? 1 + tan(x) tan(2x) = tan(2x) cot(x) -1 Answered by Penny Nom.
	The number of possible outcomes with 8 games		2003-02-21
		From Gianni: If 8 basketball games being played(no ties), which means a total of 16 teams, what are the total number of possible outcomes that can occur. Answered by Penny Nom.
	Percentage change in completion rate		2003-02-21
		From Remo: In the year 2000 300 out of a possible 600 completed a phone survey for a total of 50% completion rate. In the year 2001 20 out of 100 possible people completed the survey when it was re-done. This is a completion rate of 20% To figure out the percentage change between the years can just use the difference between the percentage figures I already have? Or can I calculate it the same as you would for non-percentage numbers. For example you gave an example here of a salary increase from $20 to $95 being an increase of 375%. Would I solve my problem the same way expect substituting my percentages (.5 and .2) in place of $20 and $95? Answered by Penny Nom.
	Deduct 60% from $150.00		2003-02-21
		From Mike: How do you get this answer? deduct 60% from $150.00 Answered by Penny Nom.
	Percentage decrease		2003-02-20
		From Hope: What number decreased by 331/3% is 30? Answered by Penny Nom.
	Density		2003-02-19
		From Rob: What is the formula for converting cubic feet to pounds? (with any substance) Answered by Penny Nom.
	Hundreds, thousands, millions,...		2003-02-19
		From Karissa and Jasmeen: hundreds, thousands, millions, - can you help us with the rest of this sequence - we are trying to find the largest number Answered by Penny Nom.
	Sasha's candies		2003-02-18
		From Pat: Tick-tac-toe Sasha and Trudy are playing tick-tac-toe. Sasha agrees to give trudy two pieces of candy for each game Sasha loses, and Trudy agrees to give Sasha three pieces of candy for each game that Trudy loses. After playing thirty games, Sasha has the amount of candy that he started with. If no ties occurred, how many games did Sasha win? Answered by Paul Betts.
	Order of operations		2003-02-16
		From A student: How is the order of operation used in everyday life other than in a math class or at school? Also .... Can you give me a list of all the mathematician that are still living that uses the order of operation? Answered by Claude Tardif.
	Numbers in base 5		2003-02-16
		From Lori: I'm trying to help my 6th grader with converting numbers like 82 to base 5 and 182 to base 12. We saw your examples on 613, but still are confused. Answered by Penny Nom.
	Order of operations		2003-02-15
		From Debbie: Question: 20-(9+4)x7=? Possible answer -71 or 49? Answered by Penny Nom.
	A determinant		2003-02-13
		From A student: I have to find the determinant of the following matrix -2 3 1 2 4 -3 0 -2 5 1 4 2 1 -3 5 2 3 4 -1 2 6 0 3 2 -4 Answered by Penny Nom.
	Wrap a rope around the equator		2003-02-12
		From Ali: If you take a rope and wrap it around the equator and then overlap it 6ft. and cut off the extra then you loosen it up so the ends meet how far would it stand off the ground? Answered by Penny Nom.
	Multiples of all four of the numbers 2, 3, 4, and 5		2003-02-11
		From Stephanie: How many of the first 1000 positive integers are multiples of all four of the numbers 2, 3, 4, and 5? Answered by Penny Nom.
	Storyteller figurines		2003-02-10
		From A student: It takes 3/4 of an hour to bake a storyteller figurine. If only one figurine can be baked at a time, how many can be baked in 6 hours? Answered by Penny Nom.
	Splitting weight		2003-02-10
		From Jin Ho: A balance scale has only two weights, 1 ounce and 4 ounces. In only three weighings split 180 ounces of seed in two bags of 40 and 140 ounces. Answered by Penny Nom.
	Finite differences		2003-02-10
		From Jenny: I need to find a formula that will work with any number. I am finding the volume of a 3d cross- shape. Here are my results so far: Term Number 0 1 2 3 4 5 nth term 1 7 25 63 129 231 1rst diff 6 18 38 66 102 2nd diff 12 20 28 36 3rd diff 8 8 8 I can't seem to find a formula that will work with any number. Any help would be much appreciated. Answered by Penny Nom.
	Three consecutive positive intergers		2003-02-09
		From Yew: Prove that when we multiply any consecutive positive intergers, the result is always divisible by 6. ex. (7)(8)(9) = 504 = 6 (84) Answered by Penny Nom.
	AABBBCCCCAABBBCCCC...		2003-02-09
		From Patty: The pattern AABBBCCCCAABBBCCCC continuously repeats. What is the 2003rd letter in the pattern? Please help, I am trying to figure out. Answered by Penny Nom.
	Millilitres and millimeters		2003-02-09
		From Iwan: I was just wondering whether a millilitre was equal to a millimetre, if not, what is there difference. Answered by Penny Nom.
	BEDMAS		2003-02-09
		From Stefanie: I do remember the rules of BEDMAS, but for some reason this question puzzles me. 6 X 9 - 3 + 44 I started with the Multiplication 54 - 3 + 44 But then I got stuck, do I proceed with adding the 44 and subtracting the 3 or figure out what -3 + 44 is, but then how would that work with 54? Answered by Penny Nom.
	Two investments		2003-02-07
		From A student: you have $7200 in principal and invest different sums @ 10% and 14%. You receive 920 at end of term. (one year)What amounts are invested at what rate? Answered by Penny Nom.
	The area of an isoceles triangle		2003-02-07
		From A student: I have to find the area of an isoceles triangle with one angle side of 30 degrees, and length of base 5. Could you please help me solve this problem? Answered by Penny Nom.
	A 15% markup		2003-02-07
		From Holly: what is 15% markup of 58.89? please show equation and why? which is correct? 58.89 divided by .85 or 58.89 times 1.15 Answered by Penny Nom.
	Two equations in two unknowns		2003-02-06
		From Patrick: What are all ordered pairs of real numbers (x, y) for which: yx2 - 7x + 12 = 1 and x + y = 6? Answered by Penny Nom.
	Transformations of pattern blocks		2003-02-06
		From Cheryl: I am trying to help my 8th grade son with Transformations - use of patttern blocks. He has to trace a figure and reflect it across the x-axis, which I can do, but then it indicates include ordered pairs - that confuses me. Answered by Penny Nom.
	Two airplanes leave Dallas		2003-02-06
		From A student: TWO AIRPLANES LEAVE DALLAS AT THE SAME TIME AND FLY IN OPPOSITE DIRECTIONS. ONE AIRPLANE TRAVELS 80 MILES PER HOUR FASTER THAN THE OTHER. AFTER THREE HOURS, THEY ARE 2940 MILES APART. WHAT IS THE RATE OF EACH AIRPLANE? Answered by Penny Nom.
	The sum of the first 1000 even integers		2003-02-06
		From Jill: What is the sum of the first 1000 even integers? Answered by Paul Betts.
	Milliliters		2003-02-04
		From James: What is a milliliter? Answered by Penny Nom.
	Factoring		2003-02-04
		From Marcin: I am having a really hard time with the factor theorem. Can you please help me with the following? (a'3 means a to the exponent 3) a)8a'3+64b'3c'6 b)8x'4-12x'3-44x'2+24x c)x'4-21x'2-100 Answered by Penny Nom.
	Filling in the back yard with dirt		2003-02-04
		From Joe: We just bought a house and need to start filling in the back yard with dirt to level it out. I measure 37'x 56' by 2' deep on an angle. I will be building a retaining wall at the 2' deep portion. The slop will go from the 2' to nothing at the top or near the house. I can't remember how to get the Sq. foot or cubic yards. Answered by Penny Nom.
	A train with 2 cars		2003-02-04
		From Michael: A train with 2 cars is traveling at a speed of 80 km/hr from town X to town y, located 800 km from each other. At the same moment that the train departed, a passenger started to walk back and forth from one end of car B to the other at a speed of 100cm/sec. Arriving in town Y, the passenger had already gone and returned 720 times. The length of car A is that of car B plus one fourth of the length of the locomotive, and the length of the locomotive equals the length of Car A plus one fifth of the length of car B. What is the total length of the train? Answered by Penny Nom.
	Problem solving		2003-02-03
		From Brigitte: My daughter is having lot's of problem with problem solving she is in grade 6. she is using mathematics in action from macmillan/ mcgraw- hill. Do you know of any way she can get help, and if there is any tests on line Answered by Diane Hanson.
	Arithmitic sequence		2003-02-01
		From A student: I am having problems solving this arithmetic sequence... 1, 5, 10, ___, 50, 1.00, ___, 10.00, ... I believe the answers to be 25 and 5.00 but I can't figure why. Answered by Claude Tardif.
	Combinations of 1,2,3,4,5 and 6		2003-02-01
		From Kyle: Today I was aked a question by my geometry teacher. It was, what is the sum of all the possible combinations of the numbers 1, 2, 3, 4, 5, and 6. He said all the possible combinations were 720. I would like to know how u could do this, and what the answer is. Answered by Penny Nom.
	1+2+3+...+500		2003-01-31
		From Brian: What is the sum of the numbers from 1 to 500 inclusive? Answered by Paul Betts.
	Triangle perimeter		2003-01-30
		From An Aunt: Hi I'm the aunt of a middle school child. He need help with two problems and I don't understand how to show he how to do them. Can you help me. How do you find the perimeter for X=4, X=0.7, and X=5/6? And an acute triangle that bottom is (3X+1) cm, left side is (X+4) cm and the right is (2X+5)cm. Can you show me not only the answer but also the steps that you used. Answered by Penny Nom.
	I have three circles...		2003-01-30
		From Tony: I HAVE THREE CIRCLE THAT IS CIRCLE TOGETHER: IN CIRCLE A, THE NUMBERS ARE: 11 I KNOW IS IN CIRCLE A, BUT I HAVE THE: 5 THAT IN A AND C, I HAVE THE 2 IN THE CIRCLE C AND B AND AND A, THE CIRCLE C I KNOW THAT 10 IS IN THE CIRCLE THE 4 IN CIRCLE A: AND B: IN CIRCLE B, I KNOW NUMBER 13 IS IN CIRCLE B; BUT I HAVE THE 3 IN CIRCLE B AND C AND I HAVE THE 2 IN CIRCLE B AND C AND A ,THE 4 IN CIRCLE B AND A. HOW DO I FIND THE SUM IN CIRCLE C AND IN B IN BOTH CIRCLE A AND B AND B AND C NOT IN CIRCLE B, AND NOT CIRCLE C. Answered by Penny Nom.
	Fibonacci exam		2003-01-28
		From Mike: My son will be participating in the national math contest. He is a grade 4 student but will be writing the Fibonacci exam for grade 5. He has been given last years exam for practice. Parents have been ask to assist for this part. I was therfore hoping for a little "inside" help on several questions with answers & short explanations. This with a would be greatly appreciated.(from last years exam) With 3 weights, Mathusalem can weigh any object that has a weight which is smaller or equal to 13 kg, but that weighs a whole number of kilograms. He wants to weigh an object of 7 kilograms. To do so, he must place two of the weights on the left side of the scale, and the third one on the right side. Which one will he have to place on the right side a)4 b)3 c)6 d)2 e)5 Mathilda uses a rectangular prisms to build stairs. The cross section of each prism is a square which has a side of 1 dm. Mathilda has already put in place 4 steps of a staircase that must have a height of 10 dm. When finished, the staircase will have a volume of 550 dm3. What will the width of the staicase in dm be? a)10 b)55 c)11 d)1 e)100 The year 1991 was the last palindrome year of the second millennium. The year 2002 is the first palindrome year of the third millennium. Including 2002, how many palindrome years will there be, altogether, in the third millennium ? a)8 b)2 c)10 d)182 e) 9 Greatly appreciated, Mike Answered by Penny Nom.
	Factoring a trinomial		2003-01-26
		From A student: how do you factor: Xsquared + 8x + 12 Answered by Penny Nom.
	Extraneous solutions		2003-01-24
		From Paul: What is an extraneous solution and in what cases do you get one? How do you know it is extraneous? Answered by Penny Nom.
	Some 5th grade problems		2003-01-24
		From Sabrina: [What is the greatest common factor of 20,28, and 36?] next problem is [5k+7(k+8)= ] next problem [Curtis simplified 0.8 divided by 0.2 x 0.04 and got 10. Latoya Simplified and got 1.6. is either correct? Can you explaine how you got the answer please.] Answered by Penny Nom.
	Dorothy and the wizard		2003-01-24
		From Ken: dorothy was going to see the wizard of oz...she stopped at the bakery and bought a box of cookies. she met the scarecrow and gave him half the cookies. she ate half of the remaining cookies and threw one half cookie away. she met the tin man and gave him half the cookies. she ate half the remaining cookies and threw one half cookie away. she met the lion. she gave him half of her cookies. she ate half the remaining cookies and threw the LAST half cookie away. how many cookies did dorothy leave the bakery with? Answered by Penny Nom.
	6 digit numbers from 0,0,2,2,4,4		2003-01-23
		From Amanda: How many 6 digit numbers can you make from the numbers 0,0,2,2,4,4, giving that 0 cannot come first. The number has to contain 2 twos, 2 fours, and 2 zeros. Answered by Penny Nom and Claude Tardif.
	The cousin of Sally's sister's boyfriend		2003-01-23
		From Michael: Sally went to a farm to buy eggs. Returning home, she gave half of them to her sister who, in turn, gave a third of those she had gotten to her boyfriend. The latter, after eating one third of the eggs that he had gotten, gave the rest to his cousin. Given that each egg weighs 70 grams, that Sally cannot carry more than 2.5kg, and that the eggs were raw, calculate how many eggs the cousin of Sally's sister's boyfriend received. Answered by Penny Nom.
	The area of a regular n-gon		2003-01-22
		From Sophie: We have been given a piece of maths coursework. A farmer has exactly 1000 metres of fencing and wants to fence off a plot of level land. she does not mind what the shape is but it must have a perimeter of 1000m. She wants to fence off the plot of land which contains the maximum area. Investigate the shape, or shapes that could be used to fence in the maximum area using exactly 1000 metres of fencing each time. I have investigated many shapes, and I feel that a circle will have the biggest area. However we have also been asked to investigate shapes with 20 and 30 sides. My dad said that there is a formula for finding out any area of land. Do you know of this formula, if so I would be very grateful if you were to email it to me. Answered by Penny Nom.
	Rational expressions		2003-01-22
		From A student: // = the main fraction line 1.) a+1/a-1 + a-1/a+1 // a+1/a-1 - a-1/a+1 2.) 2/a(squared)-3a+2 + 2/a(squared)-a-2 // 2/a(squared)-1 + 2/ a(squared)+4a+3 Answered by Penny Nom.
	The least common denominator		2003-01-21
		From Brittan: Hi there I need help! My name is Brittany and i am in the 6th grade. I need help finding the least common denominator(LCD), and the book says Find the LCM of the denominators and i've done that and then it says write equivalent fractions,using the LCM as the least commonn denominator.The directions say Use the LCD to write each pair as like fractions. and the problem is 1/8 and 5/40. Could u explain how in the word u do this? Thanks a lot Brittany Answered by Penny Nom.
	A penny, a nickel, a dime, a quarter, and a loonie		2003-01-21
		From Blaine: I have 5 coins: a penny, a nickel, a dime, a quarter, and a loonie. How many different amounts of money could I pay using any combination of these coins? Answered by Penny Nom.
	Jo's books		2003-01-21
		From debra: Jo announces: I have no more than 999 books. Jean says: No Jo, You have fewer than 1,000 books. Mary says: Jo has at least 1 book. Only one of these statements is true, How many books does Jo own? I do not know HOW to approach this problem and solve it. Answered by Penny Nom.
	Why quadratic?		2003-01-21
		From Dan: Why are equations of the form aX2 + bX + c =0 call quadratic? The quad indicates 4 but the power is 2. Answered by Penny Nom.
	Cutting a board		2003-01-20
		From George: A person has a sheet of board which he saws into two (2) pieces. The length of the first piece is two thirds the length of the original board, while the length of the second piece is four feet longer than the first piece. How long was the original board? (the length is defined as the longer of the two sides of the board) Answered by Penny Nom.
	Division by zero		2003-01-19
		From David: I've been to your site and am interested on the subject of division by 0. It's easy enough to give answers, but it's very hard, especially in this case, to make someone understand a mathematical problem. It's been about a year since my Calc class, and we never went over division by 0, only infinite numbers and such. My question is: How would you work a problem of (real number) / 0 ? As ignorant as it may sound to you, I am having trouble grasping this since I've only begun to understand some of it. Perhaps you could help. Answered by Harley Weston.
	25% more		2003-01-16
		From Charlie: If I buy something for $10 and want to sell for 25% more, do I multiply by 1.25 or divide by .75? Or another way - why do I get $13.33 when dividing by .75 ? Answered by Penny Nom.
	Radians		2003-01-16
		From Erikson: I am a student in the 10th grade and attending advanced math at my high school. I was assign to do a report about the unit circle and the radian. But there seems to be no information available about the history of the radian; who first found out about them, which civilizations used it if any. Well, hopefully you'll assist me in this troubling question. Thank you for your kind consideration. Answered by Penny Nom.
	0.027 acres		2003-01-16
		From Cory Lee: How many square feet are in How many square feet are in .027 acres?? Answered by Penny Nom.
	NO RED-HATTED DWARVES ALLOWED		2003-01-14
		From Dulce: There are 1000 dwarves in Dwarfland. Now as you know, dwarves are born with either red or white hats on. The dwarves in Dwarfland love to party. Every night, they all flock to the same club to dance the night away. One day, a sign is posted at the club: "NO RED-HATTED DWARVES ALLOWED". A certain number of days pass, after which all of the white-hatted dwarves are in attendance,and none of the reds. How did the red hats know not to come? Assumptions: The number of red and white-hatted dwarves need not be equal. There are at least 1 of each color. There are no reflections or mirrors in Dwarfland (i.e. the dwarves can't see the color of their own hat), and no dwarf can reveal through direct or indirect means the color of another dwarf's hat. There is NO COMMUNICATION among dwarves No white-hatted dwarf ever misses a night of partying Answered by Claude Tardif.
	Collinear Points		2003-01-13
		From Gary: Which of the 4 points are collinear when you construct the following concurrent lines or rays of a triangle? P(1), the point where the angle bisectors intersect. P(2), the point where the altitudes (or extensions) intersect (inside or outside of the triangle). P(3), the point where the medians intersect. P(4), the point where the perpendicular bisectors (or extensions) of the three sides of a triangle intersect. This is for my 9-12 high school class in geometry. My name is Gary Thanks for your help. Gary Answered by Harley Weston and Chris Fisher.
	Would it be worth paying $20K for 4 chances...		2003-01-13
		From Steve: If I've got 4 chances to to achieve X goal, and in each chance that I have I've got a 65% chance of achieving this goal, what is my overall probablity of achieving this goal? Also, what would it be after each of my 4 chances (i.e., for my 2nd chance, would it be (.65 * (.65*.65)? I've forgotten some basic probablity theories, and would appreciate any help on this. With the probablities above, would it be worth paying $20K for 4 chances to achieve the goal or $8.5K for only 1 chance to acheive the goal? (at 65% probability) Answered by Andrei Volodin.
	5x(-2)-32/8		2003-01-13
		From A student: I'm having problems solving this question: 5x(-2)-32/8 Answered by Penny Nom.
	What is larger than infinity?		2003-01-12
		From Dana: What is larger than infinity? Answered by Claude Tardif and Harley Weston.
	Cubic yards in a gravel pile		2003-01-10
		From Ron: I am looking to find a way to measure gravel piles to get yards. They are generaly not square.it would be like pouring sand out of a bag into a pile. they generaly are concave in dimension. can you help. I have attached a picture to show a small scale what I am working on is in much larger volume. Answered by Harley Weston.
	A rectangular prism		2003-01-09
		From Julie: How many faces on a rectangular prism and how many bases? Can the base also be a face and can a face also be a base? Answered by Diane Hanson.
	Intercepts		2003-01-08
		From Nay: my name is nay 8th grade student how do i figure out an intercep and does it always have to have (0, ) or ( ,0)? Answered by Penny Nom.
	Repeating decimals		2003-01-08
		From A student: If k=.9repeating, and 10k=9.9repeating then 10k-k=9k, k=1 therefore .9repeating=1 and 1/3=.3repeating 3x1/3=.3repeatingx3, 3/3=.9repeating, therefore 1=.9repeating It would seem to me that .9repeating approaches one but never quite makes it. Can you clarify? Answered by Penny Nom.
	The area of my lot		2003-01-07
		From Linda: I have a lot that is 210 feet in the front, 240 feet in the back and the sides each measure 150 feet. How many square feet is this all together and how close to an acre is it? Answered by Penny Nom.
	Integration of 1/(2+cos(x))		2003-01-07
		From A student: integral from pi to 0 of dx/(2+cos x) i used the substitution t=tan(x/2) and i ended up with integral from +infinity to 0 of 2dt/(t2+3) which looks like an inverse tan function , and i ended up with sqr(27)/2 pi , which is not the same as my calculator's answer , so i suspct i am doing some thing wrong. can some one tell me where i am going wrong please. Answered by Penny Nom.
	Mean and median		2003-01-04
		From Jan: I have a question re: mean and median. I know what the difference is but just need some clarification on when you would use the mean and when you would use the median. Isn't it the case that with a skewed distribution the average (mean) would be higher or lower than the median, but with a normal distribution they would be very similar values? If you have any examples to help explain this that would be greatly appreciated. I am a teacher (of sorts!) and the person who is asking me the question is actually my boss! Answered by Penny Nom.
	Constructions of polygons		2003-01-03
		From Garrett: Our teacher just finished the constructions unit, and he mentioned briefly about odd sided figures such as pentagons and septagons, only that they're very hard. My question is, how do you draw, with a compass and a straight edge, a pentagon and septagon? Answered by Chris Fisher.
	Two numbers have a ratio of 5:3		2003-01-01
		From Patricia: Two numbers have a ratio of 5:3. The larger number is 36 more than half the difference of the two numbers. What are the two numbers? Answered by Penny Nom.
	Augmented matrix		2002-12-31
		From Michelle: I am trying to augment a matrix so that i can find the values of the variables a, b, and c. For the life of me i can't find a solution to the matrix: 3 -5 2 ' 22 2 3 -1 ' -9 4 3 3 ' 1 I thank you for your help, Michelle Answered by Penny Nom.
	Successive coefficients in Pascal's Triangle		2002-12-27
		From Quincy: There is a formula connecting any (k+1) successive coefficients in the nth row of the Pascal Triangle with a coefficient in the (n+k)th row. Find this formula Answered by Penny Nom and Walter Whiteley.
	Averages of Averages		2002-12-21
		From Amy: If in the month of October the % of Payments Received was 80.74% and in November it decreased to 69.36%. Can you take the 80.74-69.36/69.36 to get the % of difference. In otherwords can you take the % of difference when the numbers you are comparing are %'s???? Can you also take an average of an average? For example, average number of payments received in October was 25.00%, average number of payments received November was 50.00%, and the average number of payments received in December was 15.00%. Do you average (25.00%, 50.00% and 15.00%) or do you have to go back to the numbers that calculated the averages. For example, October 25.00% was based on 25 payments being received out of a possible 100. So instead of taking the average of the averages, do you take the average payments and the average customers over the 3 months and calculate the average??? Answered by Harley Weston.
	20% of 40% of 500		2002-12-19
		From Richard: What is 20% of 40% of 500? Answered by Penny Nom.
	The intersection of conics		2002-12-19
		From Glenda: We are studying systems of equations where two conic sections are the two equations that we are solving simultaneously. We were studying the number of solutions that are possible if you have an ellipse and a parabola. We all agree that there can be none, one, two, three or four solutions. The question that the students had for me was whether or not a portion of an ellipse and a parabola can overlap and thereby allow an infinite number of solutions. What should I tell them? Answered by Chris Fisher and Harley Weston.
	The units digit of 2 to the power of 31921		2002-12-18
		From A student: If 2 to the power of 31921 is multiplied out, what will be the units digit? Answered by Penny Nom.
	Odd and even		2002-12-17
		From Martin: I am a graduate engineer trying to teach single digit addition to my 8 year old grand-daughter. My questions follow. Assume a child does not know what multiplication and division are. Assume the child knows how to count from 0 to 10 How do you explain that 2, 4, 6, 8 and 10 are even numbers And 1, 3, 5, 7 and 9 are odd numbers And these three facts? when you add two even numbers, the answer is even when you add two odd numbers, the answer is even when you add an even number and an odd number, the answer is odd? Can all of these be reasoned out, without using the concepts of multiplication or division? Answered by Diane Hanson.
	Calculations		2002-12-15
		From Mahdi: This problem is rather general, but it usually makes a lot of problems. I almost have no difficulty in math and physics questions, but unfortunately I'm not at all accurate in simple one or two digit calculation. I even sometimes make silly mistakes in simple sums like 7+4=12 or 4+5=11! Is there any effective way to reduce these mistakes? Answered by Walter Whiteley.
	A bouncing ball		2002-12-14
		From Eman: Q : When a childís ball is dropped from a height h metres on to a hard, flat floor, it rebounds to a height of 3/5h metres. The ball is dropped initially from a height of 1.2m. Find the maximum height to which the ball rises after two bounces. Find the total distance that the ball has traveled when it hits the floor for the tenth time. Assuming that the ball continues to bounce in the same way indefinitely, find the total distance that the ball travels. Answered by Penny Nom.
	Two modes		2002-12-12
		From ali: I have a math assignment to pick the mode in a set of data. 12 and 21 both appear twice in the data set. What is the mode? Answered by Penny Nom.
	Units		2002-12-12
		From Debbie: The general equation for a parabola is y = ax 2 + bx + c, where a, b, c are constants. What are the units of each constant if y and x are in meters? Answered by Penny Nom.
	Construct a pentagon		2002-12-12
		From Mary: We were wondering what the instructions/formula, step-by-step, is to make a pentagon. Answered by Chris Fisher and Penny Nom.
	A sphere with a hole - cylindrical shells		2002-12-11
		From Kathy: Suppose you make napkin rings by drilling holes with different diameters through two wooden balls (which also have different diameters.) You discover that both napkin rings have the same height, h. Guess which ring has more wood in it and why. Check you guess: Use cylindrical shells to compute the volume of a napkin ring created by drilling a hole with radius r through the center of a sphere of radius R and express the answer in terms of h. Answered by Penny Nom.
	Factoring		2002-12-11
		From Larry: Question: how do u factor trinonmials EX: X 3 + Y 3 X 3 - 8Y 3 8X 2 - 72 64A 3 - 125B 6 Answered by Penny Nom.
	Find a, b and c		2002-12-10
		From Sameer: Question: a+b+c=180 b=a+(120/2-5) c=b-(130-10)/6 a=? b=? c=? Answered by Penny Nom.
	Fractions		2002-12-10
		From Jean: What are some activities to use with advanced students in grade 7 to apply their knowledge of fractions and decimals. I'm looking for a project type of activity. Answered by Diane Hanson.
	Quadratic equations		2002-12-10
		From Katie: just bugging the hell outta me and I cannot figure it out for the life of me. 1)x-2x-1 =0 Find both roots. You must simplify both of your roots. This equation requires the use of the Quadratic Formula. I have tried everything for this and I am still either getting the wrong answers, and end up getting really frustrated. If you could find the answers and tell me how you did it I would greatly appreciate it! Then the second problem is 2) The square of a certain negative number is equal to 70 decreased by 3 times the number. Find the answer! On this one I set it up but still came out with the wrong answer. So if you could help me on this one I would greatly appreciate it! Answered by Penny Nom.
	y = 1 - sin(x + 60)		2002-12-10
		From Eman: Sketch the graph of y = 1 - sin(x+60). for 0 <= x<= 360, giving the coordinates of the maximum and minimum points and the pints where the curves crosses the y axis. Answered by Penny Nom.
	ALL of the possible 3 digit combinations of 0 - 9		2002-12-09
		From Melissa: I need to find out ALL of the possible 3 digit combinations of 0 - 9. Eg: 000,001,002,003. This is going to take me VERY LONG time. Any suggestions. Answered by Penny Nom.
	How many billions equal one trillion?		2002-12-07
		From Ryan and Aylah: How many billions equal one trillion? We believe that the answer is one thousand times one billion equals one trillion. Please help us with the answer to this question. Answered by Penny Nom.
	A function that is onto but not one-to-one where f:N-->N		2002-12-06
		From Lisa: A function that is onto but not one-to-one where f:N-->N Answered by Penny Nom.
	Integer arithmetic		2002-12-05
		From A student: Would you please help me with a question? I am just learning about integers. Can you show me in a way I might understand....My teacher can tell me what is required to do the math, but it just doesn't make sence to me. (+4) - (-3) =+7 Why is the answer not +1 Answered by Diane Hanson.
	A rope trick		2002-12-05
		From Jerry: My name is Jerry and I am a math teacher at the secondary school level in the greater Toronto area. I posed the following problem to my enriched grade 10 math class that I found in the book called "Mathematics and the Imagination" by William Kastner. According to the author, it is posible for two people linked to each other with two ropes around their hands, to separate themselves without letting go of the rope. The students had lots of fun trying to accomplish this problem using skipping ropes from the Phys Ed department, but with no success. Answered by Penny Nom.
	Factoring a cubic		2002-12-05
		From Dorota: I got a problem with factorise the expression 2x3+11x2-5x-50. Answered by Penny Nom.
	Which is the better buy?		2002-12-04
		From Lynda: my question is the big can held 18 ouces and cost $2.52.The small can held only 12 ounces and cost $1.08. Find both unit prices. which can was better buy? Answered by Penny Nom.
	65,125		2002-12-04
		From Brittany: I am a three-digit number.When you reverse my digits,a larger number is formed.the product of me and the new number is 65,125.What number am I. Answered by Chris Fisher and Claude Tardif.
	The dimensions of a box		2002-12-03
		From Paula: My son, who is in secondary school, needs to make a box with the inside dimensions of 1.25 cubic feet. It's supposed to be more in the shape of a rectangle than a square. I would like to know the equation to use to find the inside dimensions of a box if I know how many cubic feet (or inches) I need the inside to be. Answered by Penny Nom.
	A Normal probability problem		2002-12-03
		From A student: The height of married men is approximately normal with mean 70 and standard deviation 3. The height of married women is approximately normal with mean 65 and standard deviation 2.5. What is the probability that a random married woman is taller than a random married man? Answered by Andrei Volodin.
	A geometric sequence		2002-12-02
		From Wanda: the fifth term of a geometric sequence is 5/16. the common ratio is 1/2. What are the first four terms of the sequence. Answered by Penny Nom.
	Tiffany plays first board for her middle school chess team		2002-12-02
		From Patty: Tiffany plays first board for her middle school chess team. Since she joined the team last year, she has won 27 of 51 tournament games. That's a winning percentage of about 53%. If Tiffany went on a winning streak, how many games would she need to win in a row to raise her winning percentage to 60% Use variables and equations to communicate the method you've used to solve the problem. Answered by Penny Nom.
	How do you estimate the equation of a parabola?		2002-12-01
		From Audrey: How do you estimate the equation of a parabola? I have a project where a must find parabolas in magazines and then estimate their equation. Answered by Penny Nom.
	Trigonometry		2002-12-01
		From Lance: My question is: FIND ALL SOLUTIONS cosx=1-sin(x/2) if x[0,2pi) ALSO: Given cscx=-5/4 and cot>0, find csc(x/2) and cot(x/2) Answered by Penny Nom.
	Trigonometry problems		2002-12-01
		From Chiara: Find tan 35pi/4 Graph y = cos2x - 2sinx Answered by Penny Nom.
	The height of a triangle		2002-11-29
		From Dean: Could you please tell me the formular for me to calculate the height of a triangle. I have the angles and side lengths. I am trying to calculate the height of an isosceles triangle, does this make a difference from a normal triangle or is the formular the same. Answered by Penny Nom.
	Constructing a tangent to two circles		2002-11-28
		From Tom: I have two circles, different sizes a known distance from each other. We know the radii of the circles. How do I construct a line that is tangent to both circles relative to the segment that connects the centers of both circles? Answered by Chris Fisher and Penny Nom.
	x + y=80 and x + z=100		2002-11-28
		From PJ: x + y=80 x + z=100 can you solve for x, y or z? Answered by Penny Nom.
	Miles per hour		2002-11-28
		From Liz: If a car has traveled 16 miles in 30 minutes, how many miles per hour did they go? Answered by Penny Nom.
	The length of an arc		2002-11-27
		From Nancy: If all I have is the length between 2 ends of an arc (72"), how do I find the length of the arc at its apex and the radius? Answered by Penny Nom.
	Combinations of 1,2,3,...,10		2002-11-27
		From Gord: If I had the numbers from 1-10 how many different combinations would i have.....would it be 100....since that is 10 squared. Answered by Penny Nom.
	[x*(x+2)] + 1 = (x+1)(x+1)		2002-11-27
		From Melissa: While teaching the multiplication table to my daughter I noticed an interesting pattern. It goes something like ...Take a whole number ...add two to it ...multiply the two numbers together ...add one to the resulting number ...it will now be equal to the original number plus one, squared. Answered by Claude Tardif.
	Making 7		2002-11-26
		From Bill: At one time I had the answer to this math equation but I have lost it and can't seem to regain it. I may be going at it wrong but as I recall there were the numbers 1 through 4, and the std operators, +, -, /, *, and parentheses. The object was to make the four numbers with the operators equal to 7. Each number and operator may be used only once. My 9 year old loves these quizzes but I can't give it to her if I can't provide the correct answer. Answered by Claude Tardif.
	A two stage rocket		2002-11-26
		From Hoda: a two stage rocket accelerates in free space by ejecting fuel at a constant relative speed , v(ex). the full fuel load makes up 80% of the initial mass of the entire two stage rocket . the rocket accelerates from rest until at the end of the first stage when 75% of its fuel has been burnt. find an expression for the speed of the rocket at the end of the first stage in terms of v(ex). Answered by Claude Tardif.
	A lampshade from a cone		2002-11-26
		From Ellsie: I need to make a pattern to cover an old lampshade. This is actually the bottom portion of a cone. Please help me figure out how to draw this pattern, so that we can complete our project. Answered by Penny Nom.
	Decimals in everyday life		2002-11-24
		From Fritz: How do you use decimals in your every day life? Answered by Penny Nom.
	Factor completely		2002-11-21
		From Shelley: these two questions are to be factored completely but i have no idea how to factor them (x-4y) 2 - 3(x-4y) - 4 x 6 + y 6 Answered by Penny Nom.
	Filling A swimming pool		2002-11-21
		From Sarah: A swimming pool is being filled by three pumps. Alone pump A would take 6 hours, pump B would take 3 hours, and pump C would take 3 hours. If all three pumps are used to fill the pool, what fraction of the process is pump A. Answered by Penny Nom.
	The volume of a juice jug		2002-11-21
		From Edward: I try to find the measurement for a juice jug. I have the height of the jug and need the jug to hold 2.5 Liter of juice. Can you help me out with the formula. Answered by Penny Nom.
	Performance reviews		2002-11-21
		From Lara: Perhaps you can help. He's doing performance reviews at work. The average performance review is 3.92 on a 5.0 scale. This person would receive a 3.5% raise for next year. The highest performance review is 4.9 and this person would recieve a 6.0% raise for next year. How do I solve for the other performance review numbers. Answered by Penny Nom.
	What percent is the same as three eighths?		2002-11-21
		From Katelin: What is the percent of three eight's? Answered by Penny Nom.
	Composites, primes, factors and common factors		2002-11-20
		From Connie: My son can't remember what a composite number is, what a prime number is and the explaination of factors and common factors. Help! Answered by Penny Nom.
	Differentiating inverses		2002-11-20
		From Amy: f(x)= x3+x+1, a=1 find g'(a) (g = f -1). I am having trouble finding g(a). Answered by Penny Nom.
	4 x abcd = dcba		2002-11-20
		From A student: Say you have a four digit number (e.g. abcd) and you multiply the number by 4. The answer you get will be the reverse order of the number you started with (dcba). What is the number? The four digits (a,b,c,d) cannot be the same number or cannot be repeated. Answered by Penny Nom and Claude Tardif.
	abc,abc		2002-11-20
		From Pam: Prove or disprove that "every number of the form abc,abc (where a, b, and c represent digits) is divisible by 7,11, and 13" Answered by Penny Nom.
	Round to hundredths		2002-11-19
		From Brittany: Can u tell me how to do a problem like this: 35 divded by 4.8= Round to hundreths. Answered by Penny Nom.
	Why is 5 divided by 1/7 greater than 5 divided by 2/3?		2002-11-19
		From Elizabeth: Without performing the division, explain why 5 divided by 1/7 is a number greater than 5 divided by 2/3. Is the least common multiple of two prime numbers always their product? Why or why not? Answered by Diane Hanson and Penny Nom.
	The horse race		2002-11-19
		From Pat: The Horse Race Three horses run a race. In how many different ways can the three horses finish the race if ties are allowed? Answered by Penny Nom.
	A cubic		2002-11-18
		From Jessica: "For what values of the constant p does f have 3 distinct real roots?" The function is f(x)= x3 - 6x2 + p, where p is an arbitrary constant. Answered by Claude Tardif and Penny Nom.
	Gears and ratios		2002-11-17
		From Matt: if gear A has 12teeth and Gear B has 16teeth and gear C has 10teeth and gear A turns 40 times how many times will gear C turn Answered by Penny Nom.
	The 24 game		2002-11-16
		From Michael: Hello, my name is Michael and I am in elementary school .. We have a game we play in math class called 24 game. In it each card has 4 numbers on it. Each number can only be used once, in any order, using multiplication, subtraction, division, or addition. We are stuck on one and wondered if you could help. The four numbers are 10-9-16-4. And they must equal 24. Any clues? Answered by Penny Nom.
	A 40% markup?		2002-11-15
		From Amy: Please help? I own a basket and bouquet company, I have two retail stores with a markup of 40% on the price of the items I sale to them. I do not understand their conversion chart and I hope you can help me. A bouquet that I sale for $12.50 wholesale to the retail is marked up at a rate of 1.675 or (40%). I do not understand how the calculation of 1.675 is arrived at ... how is this 40%. I was told to multiply my wholesale price of $12.50 X 1.675 and I would arrive at the markup price of 40% the retailer would sale the item for. Answered by Penny Nom.
	The product of two consecutive numbers is 41 more than their sum		2002-11-15
		From A mother: THE PRODUCT OF TWO CONSECUTIVE NUMBERS IS 41 MORE THAN THE SUM OF THE NUMBERS. WHAT ARE THE NUMBERS? Answered by Penny Nom.
	The substitution method		2002-11-15
		From A student: Solve by using the substitution method. x = 3y - 1 x + 2y = 9 Answered by Penny Nom.
	A pattern in a table		2002-11-14
		From Thamar: how do you solve for pattern in a table like the top row is 2 6 12 17 z the bottom row is 9 13 19 24 blank question ask in each blank space write a rule to find the next number in the table Answered by Penny Nom.
	Algebra		2002-11-13
		From Carol: I am a confused parent trying to help my dau hgter solve some math problems and I need help. 3[x-4]=27 Answered by Penny Nom.
	For what divisors can you get a remainder of 8?		2002-11-13
		From David: When dividing a 3-digit number by a 1-digit number, for what divisors can you get a remainder of 8? Answered by Penny Nom.
	The volume of water in a hose		2002-11-13
		From David: I trying to find out how much water 500 ft of 3/4 inch hose will hold. I'd also like to know how you figured the answer. Answered by Penny Nom.
	Subdividing a circle		2002-11-11
		From David: Say you have a cirlcle. Then you draw 2 dots on the circle. Then you connect the dots with lines. The circle is divided into 2 parts. If you do the same with 3 dots and connect each dot to each dot with a line then you get a circle with 4 parts. 4 dots with lines connecting all (6 lines) = 8 parts.... Answered by Claude Tardif.
	Fuel consumption		2002-11-11
		From Guy: When a car is driven 'normally' the feul consumption is 7.5 per litres per 100km. On a particular journey the car was driven in 'hard' and the consumption changed to 9.1 litres per 100km. Fuel cost 80p per litre. Calculate: a) The extra feul consumed. b) The extra cost of feul, in pounds, for the journey when the car was driven in 'hard'. Answered by Penny Nom.
	Radicals with fractional radicands		2002-11-11
		From A student: how do I simplify radicals with fractional radicands? ex. 7sqrt(2) + sqrt(50) - 2sqrt(18) 10sqrt(3/5) - 24sqrt(5/3) 3sqrt(2/9) + 1/2sqrt(32) + sqrt(9/8) Answered by Penny Nom.
	x intercepts		2002-11-10
		From Laura: Find the x intercepts for the graph of the equation. x 2 - x - 12 = 0 Answered by Penny Nom.
	(93+n)+158=93+(28+158)		2002-11-10
		From Parents: (93+n)+158=93+(28+158) Answered by Penny Nom.
	A bus is 60% occupied		2002-11-09
		From Joe: A bus with a seating capacity of 60 people is 60% occupied. At the next stop one-third of the people get off the bus and 3 people get on the bus. The bus is now ___% occupied. Answered by Penny Nom.
	Three bags of marbles		2002-11-08
		From A student: I have 3 bags of marbles 1 bag is labeled blue; 2nd bag is labeled red; 3rd bag is labeled blue & red all the bags are mismarked your job is to take one marble from 1 bag look at it and correctly label all the bags Answered by Penny Nom.
	Prime numbers		2002-11-08
		From Lonna: Is 2 a prime number or not?? Why is 1 not considered a prime number? Answered by Penny Nom.
	Two tanks of water		2002-11-08
		From A student: A 2000 L tank containing 550 L of water is being filled with water at the rate of 75 L per minute from a full 1600 L tank. How long will it be before the two tanks have the same amount of water? Answered by Penny Nom.
	Cubic centimeters		2002-11-07
		From Rita: Was in emergency room yesterday-MD aspirated 40cc of fluid from my knee--what does a "cc" equate to? Answered by Penny Nom.
	G = 3H - 5		2002-11-07
		From Kash: G=3H-5, for H solve for the given variable Answered by Penny Nom.
	The identity property		2002-11-07
		From Stephanie: I am a student teacher this semester in the third grade. I was looking at our math competencies and saw that we needed to teach the identity property. Is this the same as the distributive property? If not, what is it? Answered by Penny Nom.
	Chisanbop		2002-11-07
		From Paul: I'm trying to find the book/books that explain this system? I have one small book that explains the very beginning of the system, but covers only about 10 to 20%. I'v tried several book sellers and have had no luck. Answered by Diane Hanson.
	Substitution		2002-11-06
		From John Paul: I took a math test last week, and there was a problem which the teacher checked as incorrect. It was: Solve: (a)RcTc=360;(b)RmTm=480;(c)Rm=2Rc; (d)Tm+Tc=15 I solved the problem and I got the following values for each variable. For Rc=40 For Tc=9 For Rm=96 For Tm=5 I don't see nothing wrong, but the teacher checked it as wrong. Could it be a checking mistake? Answered by Claude Tardif.
	Determining a parabola		2002-11-06
		From Shelley: let (0,3) and (1,9)and (-1,1) be given points in a parablola. Determine a b and c Answered by Penny Nom.
	What is nth term?		2002-11-06
		From Joga: What is nth term: First sequence: 2, 4,7,11, 16, nth term Second sequence: 4,10, 28, 82, nth term Answered by Penny Nom.
	18m-11+ -7		2002-11-06
		From Sophia: what is 18m-11+ -7 (m = to 12)? Answered by Penny Nom.
	A house's selling price		2002-11-05
		From Tanisha: a CERTAIN REAL-ESTATE AGENT RECEIVES $6 FOR EVERY $100 OF A HOUSE'S SELLING PRICE. HOW MUCH WAS A HOUSE SOLD FOR IF THE AGENT $10,725._ Answered by Penny Nom.
	Compass points		2002-11-05
		From Mhairi: I was asked this in maths but I am not sure if it is geography. Name all the compass points? We have been given 8 but he told us there is more and we have to name them. Answered by Chris Fisher.
	The percentage grade of that hill		2002-11-05
		From Cathy: If there is an 80ft climb over a kilometer(about 3280ft) what is the percentage grade of that hill? Answered by Penny Nom.
	An octagon of perimeter 1,000 meters		2002-11-05
		From Stephen: my son has to work out the area of a octagon with a outside perimeter of 1,000 metres, Answered by Penny Nom.
	Clown has eight steps to climb		2002-11-05
		From A mom: I'm a parent of a grade two student. What is the best way to help my son figure out a math comprehension problem? Clown has eight steps to climb, is shown in a picture with front foot on third step and behind foot on first step. Each time he climbs three steps, he falls back two. How many times did he have to climb up to reach the top. Should I get him to do a line graph or math equations. On his own he came up with the answer seven. I think the answer is six. I did 0+3=3, 3-2=1, 1+3=4 and so on, In think my why is alittle confusing to him. Is there a simplier why to explain it to him. Answered by Diane Hanson.
	A twelve-volume set of encyclopedias		2002-11-04
		From Ron: A novice librarian shelved a twelve-volume set of encyclopedias in the following order from left to right. Volumes 8, 11, 5, 4, 9, 1, 7, 6, 10, 3, 12, and 2. Using her system, where will volume 13 go? Answered by Penny Nom.
	Rounding 27.27		2002-11-03
		From A parent: If you have a problem 27.27 and you need to round to the first 7 the answer would be 27 Would 27.0 be acceptable as well or is it completely wrong. Answered by Penny Nom.
	Mathematics and Music		2002-11-01
		From Hannah: I am looking for a science fair project to compare math and music and how they relate. If you have any project ideas for me, they would be greatly appreciated. Answered by Walter Whiteley.
	How would you find the length of the chord?		2002-10-31
		From A draftsperson: If given the length of an arc and the distance from the midpoint of the arc to the midpoint of a chord, how would you find the length of the chord and the radius of the arc. The chords endpoints are the same as the the arcs endpoints. Answered by Penny Nom.
	A coin is tossed 11 times		2002-10-31
		From A student: There are 2 people that are playing a game in which a coin is tossed 11 times. The first player gets a point for a toss of heads. The 2nd player gets a point for a toss of tails. whoever gets 6 points wins. Suppose that so far the first player has 2 points and the second player has 4 points. What is the probability that the first player wins the game? Answered by Andrei Volodin and Penny Nom.
	Mrs. Klein has been losing 1 pound a week for the last year		2002-10-30
		From Brett: On her diet, Mrs. Klein has been losing 1 pound a week for the last year. Her husband weighs 110 pounds more than she does now. If his weight is twice what her weight was 6 weeks ago, how much does mrs. Klein weigh now? Answered by Penny Nom.
	An isosceles triangle		2002-10-30
		From Stan: What two different base lengths can an isosceles triangle have with sides on both remaining at 13 inches? How do I show this? Answered by Paul Betts and Peny Nom.
	A triangular prism		2002-10-30
		From Daniel: I was wondering what a triangular prism was. Answered by Diane Hanson.
	How many empty seats are there?		2002-10-29
		From Ronnie: Three new students arrived in class. Teacher says there are 210 ways you can set. How many empty seats are there in the classroom? After new student are assigned seats, how many empty seats will remain? Answered by Penny Nom.
	Variance		2002-10-29
		From Ade: I am trying to solve a standard deviation question, I have 30 data points to use, should I group the data before solving for variance or should I just use the raw data. Answered by Andrei Volodin.
	Simplifying Variable Expressions		2002-10-28
		From Erika: i would like to ask you a mathematical question on Simplifying Variable Expressions. The question is 2(n-4)+3. Answered by Penny Nom.
	Jimmy's hits		2002-10-27
		From Patty: One seventh of Jimmy's hits were doubles 12.5% of his hits were homeruns Jimmy had 82 singles He did not have any triples How many hits did Jimmy have? (Be sure to include the equation that represents the number of hits) Answered by Penny Nom.
	10 hours before 7:15		2002-10-27
		From Jessica: It is evening 7:15. What time would it be 10 hours earlier? Answered by Penny Nom.
	An identity?		2002-10-27
		From Jenna: I can't prove 1-sinQ 1 ---- = tanQ + --- 1+sinQ cosQ Answered by Penny Nom.
	The four colour theorem		2002-10-27
		From Rhonda: is there an actual equation for the four colour map theorem??? i cannot find it anywhere!! if so can you give a breif description on how it works!! Answered by Penny Nom.
	x 4 + x 5 = 100		2002-10-27
		From Bill: One of my students has stumped me. He asked how to solve the equation 4 x + 5 x = 100 All I can think of are graphing methods to get an approximate solution. What am I missing? Answered by Harley Weston.
	What are the digits?		2002-10-24
		From Ebenezer: There are three digits. The middle digit is zero and the sum of the first and last digits are is 13. When the number is reversed it is increased by 297. What are the digits? Answered by Penny Nom.
	Averaging grades		2002-10-24
		From Richard: I'm using a grading program for the first time this year. (ok, that's not a question) I require my students to record their grades in a Scorekeeper when they get them back. I'd like to know if my students can keep up with averaging their grades just as the grading programs automatically averages them when I put them in the spreadsheet. Answered by Penny Nom and Claude Tardif.
	How many trees were planted in March?		2002-10-20
		From Allison: The number of trees planted by the Alpine Nursery in April was 3 more than twice the number of trees planted in March. If 71 trees were planted in april, write and solve an equation to find how many trees were planted in March. Answered by Penny Nom.
	Is a square a rectangle?		2002-10-20
		From Nona: Are squares rectangles? Third grade math teacher told a student this was true. Grandmother needs confirmation on this! Answered by Claude Tardif and Harley Weston.
	At the zoo		2002-10-20
		From A student: The number of adults at the zoo was 2/9 the number of children. there are 700 more children than adults. The number of men was four times the number of women. The number of girls was four times the number of boys. Find the total nymber of men and boys at the zoo. Answered by Penny Nom.
	Simplify		2002-10-19
		From A student: well i need to simplify this problems out and i cant do it so here is one 3x^2+6x-45 ------------ = 3x^2+21x+30 Answered by Penny Nom.
	Exponential notation		2002-10-19
		From Ivy: I understand how to figure out for example 4 to the power of 3,what I don't understand is how to figure it out using both negative numbers and negative exponents,as an exaple -4 to the power of 6 and what makes this different that (-5) to the power of 7,please help me if you can.I am an adult taking correspondence and finding it quite frustrating. Answered by Penny Nom.
	Is it a prime?		2002-10-19
		From JV: 6x to the third power plus 5x plus 15, is that prime or not prime, and whichever it is, how can you prove it? ya dig? Answered by Claude Tardif.
	Use each digit 1-9 only one time each,...		2002-10-19
		From Megan: Use each digit 1-9 only one time each, divide the numbers into 3 groups, make one 2 digit number, one 3 digit number, and one 4 digit number. There are 6 combinations of these numbers in which you can multiply the 2 digit and 3 digit number together to get the 4 digit number (using each digit 1-9 one time each). What are they!!!!!!!!!???????????? Answered by Claude Tardif.
	An identity in trigonometry		2002-10-17
		From Alex: I really need help with proving this identity. (1+cosx+sinx)/(1+cosx-sinx) = secx + tanx Answered by Penny Nom.
	The orthocentre		2002-10-17
		From Elsie: Find the orthocentre of the triangle with vertices at A(-3,4), B(10, -3) and C(3,-2). Find the distance of point X(3,8) from the line that passes through Y(-2, -2) and Z (3, -2). Answered by Chris Fisher.
	The repetition of doing many straight forward problems		2002-10-16
		From Dan: I am the father of a very bright 9 year old girl. She is very interested in math and she grasps concepts very quickly. I am concerned that she may become bored with the repetition of doing many straight forward problems. Her current math teacher has her working in a challenging math book and she is doing 3+ digit multiplication. She misses 2 or 3 out of ten of these problems due to simple addition errors. Should she continue to practice these problems until she can get them all correct? Or, should she move on? Answered by Kathy Nolan and Claude Tardif.
	Integers in real life		2002-10-15
		From Rica: What are the real life usages of integers? Answered by Peny Nom.
	A sale price		2002-10-15
		From Chester: A jacket is on sale for 32% off. Find the original if the sale price is $89.00 Answered by Penny Nom.
	6% grade		2002-10-15
		From Micheal: When I am driving down the road and see a sign that says for example steep grade ahead 6% grade etc etc what does this mean? Answered by Penny Nom.
	Two problems		2002-10-14
		From Seçkin: i am from turkey i am a teacher in a collage i have two difficult question which i havent solve yet these are very important for me.... Answered by Claude Tardif.
	A functional equation		2002-10-14
		From Rob: Let f be a function whose domain is a set of all positive integers and whose range is a subset of the set of all positive integers with these conditions: a) f(n+1)>f(n) b) f(f(n))=3(n) Answered by Claude Tardif.
	Two problems		2002-10-14
		From Eva: a) How many different equivalence relations can be defined on the set X={a,b,c,d}? b)Show that 6 divides the product of any 3 consecutive integers. I know it is true that 6 divides the product of any 3 consecutive integers. However, i have problem showing the proof. Answered by Leeanne Boehm and Penny Nom.
	Pythagoras in three dimensions		2002-10-14
		From Miki: A room is 6m long, 5m wide and 3 m high. Find the distance from the corner of the floor to the opposite corner of the celing. Answered by Peny Nom.
	Three algebra problems		2002-10-13
		From Veronica: Solve the following inequality: 5(xsqured-4)/(xto the 5th(2x-5)to the 3rd) < or equal 0 Solve the following equations for all roots square root of x+2=-1+square root of 2x+3 what's ZERO FACTOR PROPERTY??? The hypotenuse of an isosceles right triangle is 7cm. long. Determine the lenghts of the other sides. Answered by Leeanne Boehm.
	Tree diagrams		2002-10-12
		From Denean: For lunch, students can choose juice or milk; hamburger or pizza; and a banana or apple. How many lunch combinations can the students make? In an experiment, Monty can use paper towels or cloth. He can choose red, green, or yellow food coloring. How many combinations are there? Answered by Penny Nom.
	Statistics		2002-10-11
		From Ed: Suppose 25 percent of all U.S. workers belong to a labor union. What is the probability that in a random sample of 100 U.S. workers, at least 20 percent will belong to a labor union? Answered by Claude Tardif.
	Kilometers to miles		2002-10-09
		From A student: how many miles are in 16 kilometers? Answered by Leeanne Boehm.
	Nixon, Jefferson, and Madison		2002-10-08
		From Lisa: The longest-lived US presidents are John Adams(age90), Herbert Hoover (also90), and Harry Truman (88). Behind them are James Madison, Thomas Jefferson, and Richard Nixon. The lattter three men lived a total of 249 years, and their ages at the time of death form consecutive odd integers. For how long did Nixon, Jefferson, and Madison live? Answered by Penny Nom.
	8 squares from 12 sticks		2002-10-08
		From A student: If you have 12 sticks the same size, how do you make them into 8 squares? Answered by Claude Tardif.
	Baseball, basketball and football		2002-10-08
		From Debbie: The school newspaper is interviewing 6th grade students to see what sports they follow regularly on TV. Of the 70 students interviewed; 40 enjoyed basketball; 40 enjoyed baseball; 40 enjoyed football; 20 enjoyed basketball and football; 22 enjoyed baseball and basketball; 27 enjoyed football and baseball; and 12 enjoyed all three sports. How many students out of the 70 interviewed didn't follow any one of the three sports? Answered by Leeanne Boehm, Penny Nom and Walter Whiteley.
	A complex quadratic		2002-10-06
		From Michael: I would like to know, how to solve this Complex number: quadratic equation. ix 2 + x -i = 0 Answered by Harley Weston.
	Relatively prime		2002-10-04
		From Natasha: I really need help with this middle level math question. My little brother is asking me and I have no clue what the answer is. Explain what it means when two numbers are negatively prime. (?) Answered by Kathy Nolan and Penny Nom.
	$100 is split between four guys.		2002-10-03
		From Stephan: $100 is split between four guys. A,B, C, and D. How much money does if person get if B has four more dollars than A, C has 8 more dollars than B, and D has twice as much money as C? Answered by Penny Nom.
	Rational expressions		2002-10-03
		From Ashley: 1/x(squared) + 5/xy Answered by Penny Nom.
	Exponent 0		2002-10-02
		From Debbi: can you please tell me what the exponent 0 is (i.e. 70) Answered by Penny Nom.
	The interrelations of the propositions in Euclid I		2002-10-01
		From Rob: I'm a student at St. John's College in Santa Fe New Mexico, are school is devoted to the great books and we're now reading Euclid's Elements in english and Attic Greek. We have an assignment to show a frequency or flow chart of how all the propositions of book one are interrelated. Answered by Chris Fisher.
	Two rate problems		2002-09-30
		From Rebecca: There are two small holes in the bottom of a tub filled with water. If opened, one hole will empty the tub in three hours; the other will empty it in six hours. If both holes are opened at the same time, how long will it take to empty the tub? An airplane flies 400 miles per hour in calm air. It can cover 900 miles flying with the wind in the same time that it can cover 700 miles against the wind. What is the speed of the wind? Answered by Penny Nom.
	A geometry problem		2002-09-29
		From Sonia: Given AB||CD; m a. Find the measures of b. Is there enough information for you to conclude that Answered by Penny Nom.
	0.99999...		2002-09-26
		From Erica: Yesterday in my 8th grade math class we were being taught how to convert a Repeating Decimal into a fraction. Since I, for some odd reason, seem to understand math better than the rest of my classmates, i began to drown out my teachers explaination for the rule. While she was about half way through with explaining mixed decimals i came up with an unsolvable question. Like I said before, I understand how to turn a repeating decimal into a fraction, but how would I turn a repeating .9 into a fraction? We all know it would equal 9/9, but doesn't 9 over 9 also equal 1? Even though it comes very close to one, it never really equals one. I'm very confused about this and i would love it if you could clear this up for me. Answered by Penny Nom.
	Proof by induction		2002-09-26
		From Pooh: Use induction to show that 1 2 + 2 2 + .....+n 2 = (n 3)/3 + (n 2)/2 + n/6 Answered by Paul Betts.
	Painting a car		2002-09-24
		From A student: Dan can paint a car in 4 hours. Luke can pain the same car in 6 hours. Working together, how long would it take them to pain the same car? Answered by Penny Nom.
	Number play		2002-09-24
		From Julie: Organize these numbers and the operations so that each equation is correct. Use each coice only once per equation. 36 18 12 6 - + ( ) / _________________________ = 22 _________________________ = 41 Answered by Claude Tardif.
	Dividing fractions		2002-09-23
		From Angie: When I was taught to divide a fraction, I was told to multiply the reciprocal. Many times I find I can just divide the fraction, and it saves all the simplifying after. For example, 4/6 x 9/14 divided by 2/4 I would say 4x9divided by 2=18 over 6x14divided by 4 =21, so the answer is 18/21 but if I multiply the reciprocal, I would end up with 4x9x4 over 6x14x2 which equals 144/168. So, why are we taught to do it this way? Is it necessary? Answered by Chris Fisher.
	A cone that is cut off at the top		2002-09-23
		From Stuart: I have to work out the dimensions and arcs of a cone that is cut off at the top. I.e Top diameter is 33mm to bottom diameter is 43mm and the depth is 80mm Are you able to work what the flat of this cone would be as I need to design within the flat area and then have it cut out. I really need to know what the flat of it is before it is cut and curled to form the above cone. Answered by Walter Whiteley.
	Solving an equation		2002-09-22
		From Emanuel: how do u solve these problems?: 30/x=7+ 18/2x 3m+1/4 = 2- 3-2m/3 Answered by Penny Nom.
	Ceiling		2002-09-22
		From Joe: Does the ceiling of a number mean the ceiling of 1.3 is 2 and the ceiling of 1.5 is 2 and the ceiling of 1.8 is 2. Or the ceiling of 1.3 is 1.5? Answered by Penny Nom.
	A max/min problem		2002-09-21
		From Evelina: A window is the shape of a rectangle with an equilateral triangle on top. The perimeter of the window is 300 cm. Find the width that will let the maximum light to enter. Answered by Penny Nom.
	Fractional exponents		2002-09-20
		From Jill: The problem is with fractional exponants: 10 1/3 mult. by 10,000 The 1/3 is an exponant of 10. Answered by Penny Nom.
	The entire earths' population would fit in the state of Texas		2002-09-18
		From Roz: I have been told that the entire earths' population would fit in the state of Texas and each person would have 1/2 acre. Is this true. Answered by Chris Fisher.
	How long will it be before you reach your friend?		2002-09-16
		From Margaret: Your friend runs at 8 miles per hour and you drive at 40 miles per hour, hence the diatance between you is decreasing at 32 miles per hour. You firend left 2 hours before you so how far has he gone in that 2 hours? How long will it take for the distance between you to decrease to 0 miles if the distance is decreasing at 32 miles per hour? Answered by Penny Nom.
	A Circle is evenly divided into six equal triangles		2002-09-16
		From Marilynn: A Circle is evenly divided into six equal triangles leaving an area between the outside of the circle and the one side of the triangle. This area is measured as 3.14. What is the length of the radius, one line on the triangle? Answered by Paul Betts.
	A million sheets of 30 cm long paper		2002-09-15
		From Jennifer: if you put a million sheets of 30 cm long paper end to end, how many kilometer long would the paper be from begining to end? Answered by Penny Nom.
	Formulating equtions		2002-09-14
		From Theresa: Hello. In math class we have to formulate equations for certin questions for extra credit. We are allowed to ask anyone and anyone can do it for us and explain it to us. Could you please do that? Here are the questions Jordan has 3 times as much money as Reva. Together they have $44. How much money does each have? The Tigers played 48 games. They won twice as many as they lost. How many did they win? There are 900 students in Sewickley Academy. There are 20 more girls than boys. How many girls are there? A board 400 cm long is cut into 2 pieces. One piece is 66 cm longer than the other. Find the lenght of the shorter piece. Answered by Penny Nom.
	Sums of evens		2002-09-14
		From Rosa: How do I find a geometric way to easily compute sums of consecutive even numbers 2 + 4 + 6 + .... Answered by Leeanne Boehm and Harley Weston.
	Mixing solutions		2002-09-13
		From Margaret: In a chemistry laboratory the concentration of one solution is 10% hydrocholoric acid (HCl) and that of a second soulution is 60% HCl. How many mL of each should be mixed to obtain 50 mL of a 30% HCl solution?? Answered by Penny Nom.
	Base 5 numbers		2002-09-13
		From Vera: ? how do you change a base 10 number to base 5 Answered by Penny Nom.
	How many dominoes?		2002-09-13
		From A student: Dominoes are split into two halves. If you were allowed up to 6 dots on each half, how many options of dominoes could you get? Answered by Penny Nom.
	The number of decimal places in 1 over a power of 2		2002-09-12
		From Allan: Does anyone notice that the maximum number of decimal place of the number 2 dividing 1 and its increment (4, 8, 16...etc) is the same as the power of number 2? eg. 22=4, thus the max number of decimal of 1/4=0.25 which is 2 decimal place and 2 is the number of power of 2 take 64 as example: 26=64, and take 1/64=0.015625 which has 6 decimal place (and is the power 6) Is there such a law in math? If yes, can you tell me what it is? Or is this my discovery? Answered by Paul Betts.
	Use a 4 four times		2002-09-12
		From Amanda: The question is what is if you can only use a 4 four times and get the answer 12, 10, and 6 Answered by Claude tardif.
	7+8+9+...+1000		2002-09-11
		From Shirley: My question is what is the formula for adding up numbers when you don't start with number 1? For example 3 + 4 + 5 + 6 = 18. But how could you arrive at the answer without adding all the numbers? Answered by Penny Nom.
	The quadratic formula		2002-09-11
		From Kathleen: im having a problem trying to understand quadratic formulas can u please help me i have problems like 3x2 - 4x - 11 = 0 how do i work out that problem? i have the formula written down but it doesnt seem to register for me. Answered by Penny Nom.
	The sum of the first one hundred even numbers		2002-09-10
		From Arthur: What is the sum of the first one hundred even numbers? Answered by Penny Nom.
	A fish weighs 10 pounds more than half its weight.		2002-09-10
		From Rebecca: A fish weighs 10 pounds more than half its weight. How much does it weigh? Answered by Penny Nom.
	The factor theorem		2002-09-10
		From Yael: Prove (x - a - b) is a factor of x3 - a3 - b3 - 3ab (a + b) Answered by Penny Nom.
	How do start from 2700 and get 35% back out?		2002-09-09
		From Dennis: 2000 x 0.35 = 700 + 2000 = 2700 How do start from 2700 and get 35% back out? If I have 2700, how do I figure out that 35% of 2000 is 700 and adding the two them together will get me 2700? Answered by Penny Nom.
	A linear function		2002-09-09
		From Chad: If y = 9x - 13 does it represent a linear function? And if it does what is its slope and is it a direct variation? Answered by Peny Nom.
	The community garden		2002-09-08
		From Michele: Bryce, Duanne, Juliana and Sonya share a 40ft by 48 ft rectangular portion of the community garden in the neighborhood. With this space each has their own rectangular garden plot. -Bryce is the only one with a square plot. its are is 1/2 the area of Duanne's -The area of Bryce's plot is 2/3 the area of Julianna's plot. Their plots have one side in common. -Sonya's garden has an area twice that of Julianna's garden. What are the dimensions of each person's garden plot? Answered by Leeanne Boehm.
	Algebra		2002-09-08
		From Heather: This question is from an 8th grade Algebra classs. I am a parent asking for help to explain to my child. Q: d=25t2. Answered by Leeanne Boehm.
	Mean, median and mode		2002-09-08
		From Ramona: How do you calculate the mean, median, and mode? what are each of their definitions? Answered by Leeanne Boehm.
	Weighing pumpkins		2002-09-08
		From Jennifer: Suppose five pumpkins are weighed two at a time in all possible ways. The weights in pounds are recorded as 16, 18, 19, 20, 21, 22, 23, 24, 26, and 27. How much does each individual pumpkin weigh. NO FRACTIONS! Answered by Penny Nom.
	The area of a triangle		2002-09-07
		From Phill: How do you find the area of a equilateral and other triangles? Answered by Penny Nom.
	Sanding a wooden block		2002-09-07
		From Wanda: If a wooden block, 2in height, 3in width, and 6in length is sanded and 1/8 of an inch is removed from the top and from the bottom, how much is the volume of the block decreased? Answered by Penny Nom.
	Subsets of the Real Number System		2002-09-07
		From Christine: In looking for a French equivalent of the word "integer", I found that the word seems not to actually exist in French, and that Canadian schools use the term "natural number" to describe what we have been trained to call "whole numbers," while using the term "whole number" to describe what we have been trained to call "integers." Answered by Claude Tardif.
	Social security numbers		2002-09-06
		From Chris: How many different number combinations are there for the social security system? We know that there are only a certain ammount of combinations available and the current US population is at 281 million. The number system should include as many nine digit combinations as possible using the numbers 0-9 in multiple different spots. Answered by Penny Nom.
	I am a 3 digit number.		2002-09-06
		From Jasmine: I am a 3 digit number. My last digit is 3 times my first digit. My firat digit is twice my middle digit. What numbers am I? There are at least 2 correct answers? Answered by Paul Betts.
	8,27,64 . . .		2002-09-05
		From Mike: We have been trying with no luck all night to complete the following math pattern (next 3 entries) 8,27,64 . . . Any ideas?? Answered by Penny Nom.
	What really is pi?		2002-09-05
		From Rachel: what really is pi? 3.1444 Answered by Penny Nom.
	Dan is 4 inches taller than Mike.		2002-09-04
		From A parent: Dan is 4 inches taller than Mike. Together they are 8 feet 8 inches tall. How tall is each boy in feet and inches. Answered by Penny Nom.
	1/8 in decimal form		2002-09-04
		From A student: explain how you put 1/8 in a decimal form Answered by Penny Nom.
	Intercepts		2002-09-04
		From Tamara: Why is it that the x intercept the value of y is 0 and at the y intercept the value of x is 0? Answered by Leeanne Boehm.
	1, 2, 4, 8, 16, 32, etc.		2002-09-04
		From Ginger: I've been working with finding the nth term for a few weeks, and i can't seem to figure this one out! 1, 2, 4, 8, 16, 32, etc. Answered by Leeanne Boehm.
	Monthly rent		2002-09-04
		From Al: How do you figure monthly rent if the charge is 11.00 per sq. ft. and there are 1,000 sq. feet? Answered by Leeanne Boehm.
	A limit		2002-09-03
		From Circe: Lim 3x 3+ax+a+3 /(x 2+x-2), X->-2 Answered by Penny Nom.
	Addends can be grouped differently but the sum does not change		2002-09-03
		From Jodia: I have been searching the web for over an hour & a half now for the answer to the following question: The _____ states that addends can be grouped differently but the sum does not change. Answered by Penny Nom.
	A schedule for a fantasy football league		2002-09-01
		From Steve: i am in a ten(10) team league, split evenly into two five team divisions. we play a thirteen(13) game schedule and would like to play each team in your own division twice, and each team in the other division once. according to my rudimentary mathematics that equals 13 games. a good schedule should look somthing like this: team 1-5 = division 1 team 6-10 = division 2 team 1 should play teams 2-5 twice and teams 6-10 once. Answered by Claude Tardif.
	A group of 9		2002-08-31
		From William: what is the mathmatical name for a group of nine like a group of 3 is called 'triplets' Answered by Penny Nom.
	Proof by induction		2002-08-31
		From Tabius: Use mathematical induction to prove that the following formulae are true for all positive integers: a) 1 + 3 + 5+...+(2n - 1) = n 2 b) 2 n > n. Answered by Penny Nom.
	How many cubic feet are in a cubic mile?		2002-08-30
		From William: How many cubic feet are in a cubic mile? Answered by Penny Nom.
	A square of tiles		2002-08-30
		From Rosa: How do I go about finding a formula for the number of tiles I would need to add to an arbitrary square to get to the next sized square? Answered by Penny Nom.
	38-10+12divided by4multiplied by 16		2002-08-30
		From Brenda: my math question is as follows: 38-10+12divided by4multiplied by 16=? Answered by Penny Nom.
	< and >		2002-08-30
		From Kelsey: What is the origin of the greater (>) than and less (<) than signs? Answered by Harley Weston.
	A solution to an equation		2002-08-28
		From A student: How do you determine whether a pair of numbers is a solution for an equation? If you could identify the specifics steps I need to take to determine whether it is a solution or not would be appreciated! Thanks i.e. x-4=0 Pairs of numbers as possible solutions (4,7) (3,4) (0,-4). Answered by Penny Nom.
	Student to teacher ratio		2002-08-28
		From A student: central middle school has 2470 students and the ratio of students to teachers is 26:1 how many new teachers are needed to reduce this to 19:1? Answered by Penny Nom.
	Mixing gas and oil		2002-08-27
		From Sherry: how do I calculate the correct fuel ratio for a boat motor? 50:1 the oil containers only say how many ounces to add to 5 gallons of fuel to make a 50:1 ratio.(13 ounces to 5 gallons of fuel) I have a 20 gallon tank so what if I add 11.6 gallons of fuel, what formula would I apply to get the correct measurement of oil to add? Answered by Penny Nom.
	Common Denominator		2002-08-26
		From Slobodanka: What is a Common Denominator? Answered by Penny Nom.
	The tangent to a curve and the tangent of an angle		2002-08-26
		From A teacher: Is there a relationship between the tangent of a curve(line touching the curve at one point) and tangent (the trigonometric function)? Answered by Chris Fisher.
	Divisibility of 5 2002		2002-08-25
		From Simon: I need to ask you a question if 5 2002 and 3 2002 are divisible by 26. Answered by Penny Nom.
	Express 5120 as a sum of consecutive numbers		2002-08-25
		From Todd: Express 5120 as a sum of more than 1 consecutive number. Answered by Leeanne Boehm.
	When does an inequality represent the area above the line?		2002-08-25
		From Tamara: How do you determine that an inequality represents the area above the line and when do you include the line in the solution? Answered by Penny Nom.
	Cubic yards of concrete		2002-08-24
		From Michael: if you have a 10" dia pipe 8' long how many cubic yards would it take to fill with concrete. how how would you go about figuring it out. and also if you would how many cubic feet, cubic inches in a cubic yard. i know you don't need to answer, seeing i am not in school, but would appreaciate it. Answered by Penny Nom.
	Sets and elements		2002-08-22
		From Dianne: I want to know why its okay to say that, for example, 6 is an element of the set of integers, but you get counted off for saying that the set of 6 is an element of the set of integers. How come? Answered by Judi McDonald.
	Gallons in a cylindrical tube		2002-08-21
		From Heidi: IF I HAVE A 12" DIA TUBE WITH 1/4" WALL AND 72" IN LENGTH HOW MANY GALLONS OF WATER WILL THIS HOLD Answered by Penny Nom.
	Parallelograms		2002-08-21
		From Moorthy: 11 parallel lines are intersected by another 9 parallel lines.Then how many parallelograms are formed? Answered by Walter Whiteley.
	The 20 kilometer walk		2002-08-20
		From A student: THE 1996 OLYMPIC GOLD METAL WINNER FOR THE 20 KILOMETER WALK WAS JEFERSON. HIS TIME WAS 1HOUR, 20 MIN,AND 7SECONDS. HIS TIME WAS NOT GOOD ENOUGH TO BEAT THE WINNER IN 1988 BY JOSEF. HIS TIME WAS 1 HOUR,19 MIN, 57 SECONDS. WHAT WAS THE WALKING RATE OF EACH PERSON? Answered by Penny Nom.
	Sole Mates Shoes		2002-08-19
		From Robert: Sole Mates Shoes has expenses of $9,592 per month. What must the store's total income be if it is to make a profit of 12%? Answered by Penny Nom.
	When is 1! + 2! + 3! + ... + x! a square?		2002-08-19
		From Sarathy: Solve : 1! + 2! + 3! + ... + x! = y 2 How do i find the solutions ? Answered by Claude tardif.
	Combination locks		2002-08-17
		From John: How many combinations of three number codes can occur with a standard combination lock? The range of possible numbers is 0-39 which allows 40 different possible choices each turn of the dial. Each combination requires exactly three numbers (i.e. three turns of the dial). E.g. 35-40-5. Allow for reuse of the same number three times e.g.10-10-10. I don't think there is any preference shown for certain number combinations. Can you explain how the total is derived? Someone at the YMCA this week put this question to me and I gave an answer but I am not sure I am right--so I have come to you. Answered by Penny Nom.
	Volume of a sphere		2002-08-16
		From Rahul: How do i find the volume of a sphere without the knowledge of calculus? Answered by Walter Whiteley.
	Distance in 3-space		2002-08-16
		From David: The question is: how do I figure out the distance of one object in 3D space to another object in 3D space? I have an object at say x = 5.872, y = 2.876, and z = 7.290; and the other object is at x = 1.129, y = -8.213, and z = -11.127. I have been suggested to use the pythagorean theory on this, but since there are three variables, I don't understand how. Answered by Penny Nom.
	Probability		2002-08-16
		From Chris: There are two possible outcomes for a random event, A and B. The probability of A being the outcome is 63%, and B 37%. What is the likelihood that B will be chosen twice, consecutively? Three times, ten? Answered by Andrei Volodin.
	Variable expressions		2002-08-15
		From Brittany: I am just learning variable expressions. My homework is to write a variable expression for each word phrase; example : the number of minutes in s seconds the cost of x cartons of juice at $.75 each And etc. I don't understand it Answered by Penny Nom.
	A paper model of a cone		2002-08-14
		From Bruce: I have made a paper model of a cone, cut a sloping section, and removed the top. I have drawn the major and minor axis on the paper surface of the section. The major axis is not symmetrical about the minor axis. To me, this is not an ellipse. To me, an ellipse is a tubular section, because this gives a symmetrical major axis. What is your opinion? Answered by Walter Whiteley and Chris Fisher.
	The circumference of a 72		2002-08-14
		From Linda: What is the circumference of a 72" diameter circle? Answered by Penny Nom.
	Two equations		2002-07-26
		From Derek: 1. 3x + 2y = 4 2. -7x + 2y = 24 finding x and y. Answered by Penny Nom.
	Some inequalities		2002-07-25
		From A student: 1)-5 <= -3X+1 < 1 2)4X-2 < 6 OR X+2 > 9 Answered by Penny Nom.
	Musical Scales		2002-07-24
		From Terence: Given that there are 12 notes in a musical octave, what is the maximum number of musical scales possible within that octave, if each scale has a minimum of 5 notes and a maximum of 9 and we start all the scales from the same note? In case you don't know anything about music, a scale is a progression of notes where you start on a specific note and end on that same note an octave higher. There are twelve different notes between these two similar notes. Which notes you choose to play determine the sound of the scale. Anything less than five notes would not make for a very interesting scale. Anything more than nine and you would be playing almost 'every' note in the scale, not leaving much room for distinction in how you organize these notes. I assume you first have to figure out the maximum number of variations possible in a 5-note scale (with 12 notes at your disposal). Then do the same for a 6-note scale, then a 7-note, then an 8-note, and so on. Then add up the results. How to find this maximum number of variations for each scale size though is what I don't know. Answered by Leeanne Boehm.
	20 men dig 40 holes in 60 days		2002-07-24
		From Lindsey: 20 men dig 40 holes in 60 days. So, 10 men can dig 10 holes in how many days? Answered by Penny Nom.
	x + 5 + x, if x = 4		2002-07-23
		From Elisa: x + 5 + x, if x = 4 Answered by Leeanne Boehm.
	7th grade math lesson plans		2002-07-23
		From Peter: Where can I get samples of 7th grade math lesson plans and curriculum for the whole year? Answered by Leeanne Boehm.
	As much greater than 47 as it is less than 105		2002-07-23
		From Joe: To find the number in question you need to find the number exactly half-way between 47 and 105. Another way of thinking about the number that is half-way between two other numbers is as the average of the two numbers given. Answered by Leenaan Boehm.
	Domain of a function		2002-07-20
		From Andy: I'm having difficulty in finding the domain of 1/(x2 -2x + 4) one over x squared minus 2 x plus 4. Answered by Penny Nom.
	Percentage		2002-07-20
		From Sally: If 20% of 100 is 80, then why is the percentage difference between 80 and 100 25%. Answered by Penny Nom.
	Place six numbers around a triangle		2002-07-19
		From Monika: I need to place six numbers around a triangle, as such that one number is on each corner, and one number on each side making three numbers in one line, adding up to two hundred exactly. The number I have to use are, 40, 50, 60, 70, 80, 90. I have to use each one once, there for, each number cannot be repeated. Answered by Claude Tardif and Chris Fisher.
	Can you make up a word that adds up to 1000000?		2002-07-19
		From Adrie: My question is elementary and I am a student Please help me with the following conundrum, as it is driving me crazy. 'When the letters in the alphabet are given values from 1 to 26 for A to Z, can you make up a word that adds up to 1000000 ( one million )-used as a multiplication?' Like 'cat' would be 3*1*20 = 60 Answered by Claude Tardif.
	Order of operations		2002-07-18
		From Danna: I would like to know how to solve this type of problem; I already have the answer. Problem: 2 [5 (4 + 6) - 2] = 96 Also, what do you call this type of problem? Thanks a lot. Answered by Penny Nom.
	Division by zero		2002-07-18
		From James: Why is division by zero undifined (i have to proof that division by zero is undifined) Answered by Chris Fisher.
	A rope around a post		2002-07-15
		From Nic: My daughter who is in the 10th grade asked me this ?, you have a pole 45 inches high, 22inches around. You have a rope 1/2 thick, how many feet of rope would you use to go from top bottom of pole to top. Answered by Penny Nom.
	A probability problem		2002-07-12
		From Yvonne: What is the probability of 38 people choosing the same five options, given a choice of 15? Perhaps you could just give me the formula with an explanation. I am an English teacher doing educctional research, but am stuck because I don't have the math experience to help me. Answered by Andrei Volodin.
	Two cubes		2002-07-12
		From Vanessa: The edges of a cube are 50% as long as the edges of another cube. What percent of the volume of the larger cube is the volume of the smaller cube? Answered by Peny Nom.
	Pigs in pens		2002-07-10
		From Shannon: A farmer has 21 pigs and 4 pens, he must put an odd number of pigs in each pen, how does he do it? Answered by Penny Nom and Chris Fisher.
	The Praxis II test		2002-07-09
		From A student: I am taking the Praxis II test and I can't seem to answer certain styles of questions. Please help!!!!!! In a class of 29 children, each of 20 children has a dog and each of 15 has a cat. How many of the children have both a dog and a cat? If there are exactly 5 times as many children as adults at a show, which of the following CANNOT be the number of people at the show? a. 102 b. 80 c. 36 d. 30 In order to estimate the population of snails in a certain woodland, a biologist captured and marked 84 snails there were then released back into the woodland. Fifteen days later the biologist captured 90 snails from the woodland, 12 of which bore the markings of the previously captured snails. If all of the marked snails were still active in the woodland when the second group of snails were captured, what should the biologist estimate the snail population to be based on the probabilities suggested by this experiment? a. 630 b. 1,010 c. 1040 d. 1080. Answered by Paul Betts.
	A polygon inscribed within an ellipse - Part 2		2002-07-08
		From Steven: I recently sought your advice about a problem that I have been working on for eight years or so concerning a polygon inscribed within an ellipse. I think that I may have confused matters by the way in which I put the question and hope that the enclosed diagram will clear matters up. In the ellipse below I have drawn three chords inscribed within one quadrant ( this would pertain to a twelve sided figure within the whole ellipse). These chords are exactly the same length as each other, for example if the major axis of the ellipse was 360 and the minor axis 240 I have worked out that a twelve sided figure would have sides of 78.2487. However I worked this out empirically with a method that could only be described as gruelling I would be most grateful if you could tell me of a method that would work for any ellipse and any number of sides. Answered by Chris Fisher.
	The base 10 multipliction table		2002-07-07
		From A student: These are two questions from Math for Elementary Teachers and they have me stumped. You have two coins that are worth 30 cents. One of the coins is not a nickel. What are the two coins? The product of the diagonals of any 2x2 matrix in the base 10 multiplication table are equal. Why? Answered by Penny Nom.
	A box that holds 22.4 liters		2002-07-07
		From Jon: How do I find the measurements required to make a box that holds 22.4 liters of something? Answered by Penny Nom.
	Equivalence relations on a set of cardinality n		2002-07-06
		From Siddhartha: what is the no. of equivalence and transitive relations on a set of cardinality n? Answered by Penny Nom.
	An equalateral polygon inscribed within an ellipse		2002-06-30
		From Steven: How would you calculate the length of one of the sides of an equalateral polygon (of n sides) inscribed within an ellipse ( of any eccentricity ) where all of the vertices exactly touch the perimeter of the ellipse? I know that when the eccentricity is zero ( i.e a circle ) the formula: r * (sin(180/n) * 2) will suffice. But what about when the eccentricity is greater than zero? Answered by Chris Fisher.
	Math test		2002-06-28
		From Dustin: I have a really important placement test to take in 2 weeks. I need to have a strong comprehension of algebra and I have't taken a math class in about for years. I'm 24 and am going back to school. I want to get ahead and into math 96, and must pass this test to do that. Do you know of a book or a wab site that can teach me a few formulas that will give me the edge I need. If I have the right text for the job i'll study day and night to pass. Answered by Leeanne Boehm.
	Future value		2002-06-27
		From Susan: If one were to invest $115 a month for 20 years and expect a 4% annual return, what is the value of this money in 20 years? Answered by Leeanne Boehm.
	What is the next term?		2002-06-21
		From A student: What is the next term in the sequence: 1, 5, 14, 30..... Answered by Penny Nom.
	Counting		2002-06-21
		From Rachel: How many different numbers of 2 different digits each can be formed using the digits (1,3,5,7,9)? How many triangles are formed by the vertical of a regular hexagon? Answered by Penny Nom.
	Jack and Jill wrote letters		2002-06-19
		From Angel: jack and jill each bought a stationary # of sheets of paper in each box were the same # of envelopes were the same jill wrote letters consisting of 3 pages jack wrote letters consisting of 1 page when they wrote all letters jill had 50 envelopes left and jack had 50 sheets of paper left how many pieces of paper and how many envelopes? Answered by Leeanne Boehm.
	Integrating x^x		2002-06-18
		From Jeremy: I am a student at the University of Kansas and I am wondering if there is a general anti-derivative for x x (i.e. the integral of x x dx)? I've looked in a bunch of Table of Integrals and have found nothing (can you guys find it?), so I'm sort of wondering if this may be a research type question. Answered by Claude Tardif.
	A good rule of thumb when driving		2002-06-13
		From Lisa: A good rule of thumb when driving is that you should be about one car length away from the car in front of you for every 10 miles per hour that you are travelling. Suppose you follow this rule perfectly (so you are exactly the correct distance away). You are waiting at a stop light with your front bumper just touching the car in front of you. The light turns green and the car in front accelerates at a constant rate "r". Calculate how you should accelerate in order to follow the rule. Answered by Penny Nom.
	The cross country team		2002-06-12
		From Denae: In cross country, a team's score is the sum of the first five finishers on the team. The captain of the team finished 2nd in the meet. The next four finishers on the team placed in consecutive order. The team score was 40. in what places did the other members finish? Answered by Penny Nom.
	An equilateral triangle		2002-06-11
		From Sarah: Hi. My name is Sarah. I'm a secondary student taking a Math 30C course by correspondence. The question has two parts. The first part is: Draw an equilateral triangle XYZ. Draw the altitude from X to YZ. Choose any point P inside the triangle or on the triangle. Draw perpendiculars from P to the sides of the triangle. The Second part is: Measure the altitude h and the 3 perpendiculars s, t, and u to the nearest mm. Repeat as many time as is necessary until you can state a generalization concerning h, s, t, and u. If you could help me, it would be greatly appreciated. Answered by Penny Nom.
	Drawing cards		2002-06-11
		From Ed: What is the probability of drawing without replacement from a standard deck of 52 cards the following 5 card hand ...... the ace of spades, 2 tens and 2 face cards Solution 1: 1/52 x 4/51 x 3/50 x 12/49 x 11/48 Solution 2: Using Combination theory ..... (1C1 x 4C2 x 12C2) divided by (52C5) Can you help us understand which answer is correct and why the other is not? Answered by Penny Nom.
	Successive coefficients in the nth row of Pascal's Triangle		2002-06-10
		From Tim: There is a formula connecting any (k+1) successive coefficients in the nth row of Pascal's Triangle with a coefficient in the (n+k)th row. find this formula. Answered by Penny Nom.
	0.63 of an acre		2002-06-08
		From Sherry: how many square feet are in 0.63 of an acre Answered by Penny Nom.
	Regular polyhedra		2002-06-07
		From Sandra: The other day a colleague and I were talking about polyhedra. Is regular a term applied to polyhedra or just polygons? If so, then what would define a regular polyhedron? Would it mean all faces are regular or would it mean that all faces are identical and regular? That is, could a pyramid with equilateral triangles for lateral faces and a square base be considered regular or must the base also be an equilateral triangle? Answered by Chris Fisher.
	The mean distance travelled		2002-06-07
		From A student: If Rosalia travels 1000 km Sheree travels 280 km Daniel travels 50 km Mica travels 200 km Connor travels 500 km Eric travels 250 km Hillary travels 300 km What was the mean distance travelled? How do you arrive at the answer? Answered by Penny Nom.
	Constructing the square root of 3		2002-06-07
		From Allan: I am a Math 7/8 teacher. I was wondering how you would show a student how to find the exact location of the square root of three on the number line using just a compass and a straight edge. Answered by Penny Nom.
	Perimeter		2002-06-05
		From Tava: I'm a grade four student from St. Mary school. In class we've been dicussing perimeters. So this is what we did; First we each got a piece of paper in the shape of the geoboards and our teacher told us to find as many different shapes of area of 12 square units. During this time we were given to find perimeters of shapes that had twelve square units one of our classmates discovered the biggest perimeter possible with twelve square units of 26 units. Another classmate discovered the smallest perimeter of fourteen units. Here's a question: Why are all the shapes with fourteen units all the same shape? and why are all the shapes with twenty-six units can be different? After we found the biggest and smallest shapes our teacher told us we each had to find at least one shape of the biggest and smallest. After we each foud a shape with a perimeter of twenty-six and fourteen we had to find different shapes with different perimeters. During that time we discovered different perimeters. What we found was fourteen all the way up to twenty-six, but they all went by two's. Why didn't they count up by 14, 15, 16, 17, 18 etc? I think it's because the area is an even number. See if you added one "block" or "square" to it you always add three because at least one of the sides is together with another side. Whyare all the perimeters all even numbers? Answered by Penny Nom.
	A polynomial		2002-06-05
		From Melissa: I'd like to know what is a polynomial( the definition and an explication)? And is 7x a polynomial? and why? Answered by Penny Nom.
	The area of a circle		2002-06-03
		From Jessica: I am doing a maths assigment for university, which is aimed towrds primary school students(k-6). I was wondering if you could give me some information as to how I could describe to students the rule for finding the area of circle, using a circle cut up into equal sectors (like a pizza). I know it has something to do with the fact that you can make these shapes into a parallelogram, but I am a bit uncertain as to how I can express this idea clearly and articulately to students. Answered by Penny Nom.
	Ratios and weights on Neptune		2002-06-03
		From Janice: The ratio of an object's weight on earth to it's weight on Neptune is 5:7. How much would a person who weighs 150 pounds on earth weigh on Neptune. Answered by Penny Nom.
	Ounces and cubic centimeters		2002-05-30
		From Martin: How many ounces are in 600cc of liquid? Answered by Penny Nom.
	11........1		2002-05-29
		From Un eleve: Démontrer que tout nombre impair non multiple de 5 admet un multiple de la forme:11........1 Answered by Claude Tardif.
	Conics		2002-05-29
		From Brooke: Which conic cannot be generated by an intersection of a plane and a double napped cone? Answered by Chris Fisher.
	Overlapping circles		2002-05-29
		From Naman: There are two circles, big circle with radius R and small one with radius r. They intersect and overlap in such a way that the common area formed is 1/2 pi r 2 (half the area of the small circle) If r=1, find the Radius of the big circle (R)? Answered by Harley Weston.
	The sum of the areas of two regular decagons		2002-05-27
		From A parent: The sum of the areas of two regular decagons is 39 square inches, and their radii are in the ratio of 2:3. Find the area of the larger decagon. Answered by Paul Betts.
	Linear programming		2002-05-27
		From Jes: A machine shop makes two parts, I and II, each requiring the use of three machines, A, B, C. Each Part I requires 4 minutes on Machine A, four minutes on Machine B and five minutes on machine C. Each Part II requires five minutes on Machine A, one minutes on Machine B and six minutes on Machine C. The shop makes a profit of $8 on each Part I and $5 on each Part II. However, the number of units of Part II produced must not be less than half the number of Part I. Also each day the shop has only 120 minutes of machine A, 72 minutes of Machine B, and 180 minutes of Machine C available for the production of the two parts. What should be the daily production of each part to maximize the shop's profit? Answered by Claude Tardif.
	Cubic feet and cubic yards		2002-05-27
		From John: how do you find the cubic feet/cubic yard of area 10 feet wide by 15 ft long by 2 inches high Answered by Penny Nom.
	One-fourth of a number is added to one-third of the same number		2002-05-26
		From A student: When one-fourth of a number is added to one-third of the same number, the result is 28. What is the number? Answered by Penny Nom.
	A spotlight shines on a wall		2002-05-25
		From Barb: A spotlight on the ground shines on a wall 12m away. If a man 2m tall walks from the spotlight toward the bldg at a speed of 1.6 m/s, how fast is his shadow on the bldg decreasing when he is 4m from the bldg? Answered by Penny Nom.
	A schedule for 24 golfers		2002-05-25
		From John: I am working on a schedule for 24 golfers. 6 groups of 4. I have 8 golf days (twice per week for a month). Ideally, I would like to schedule all 24 golfers in 6 different groups of 4 on each day. Here is the catch.....no golfer in any group can be grouped togther more than once. Every group of 4 each day will have 4 new golfers that have never played together before. Is this possible? Answered by Chris Fisher.
	| n + 4 | + | 3 - 2n | = 16		2002-05-24
		From Randall: I don't seem to be able to solve this: | n + 4 | + | 3 - 2n | = 16 Answered by Penny Nom.
	Blood donations		2002-05-23
		From Fiza: One particular high school encourages students to donate blood. the high school gym is set up for purpose. the distribution of blood type in north america is as follows. Type O:44% Type B:10% Type A:42% Type AB:4% (a) what is the probability that the first two people in the line up have the same type of blood? ANSWER: I donn't know how many people are in the line. so how can I answer this question. (b) what us the probability thar none of the first five people in the line up have type AB blood? Answered by Andrei Volodin.
	3 radians subtends an arc of 27 meters		2002-05-22
		From Kyle: In circle O, a central angle of 3 radians intercepts an arc of 27 meters. Find the number of meters in the length of the radius. Answered by Penny Nom.
	Bob swam across a river		2002-05-22
		From Torri: Bob swam across a river 420 ft wide. A strong current carried him 580ft downstream as he swam. Find x, the distance bob actually swam. Answered by Penny Nom.
	Telephone banking		2002-05-22
		From Fiza: To use telephone banking to pay bills, the customer has to enter the last three digits of each bill. the numbers 0 to 9 can be used. if the number happened to be the same on more tan one bill, the customer has to enter the first three digits as well. (a) what is the probability that a person has 2 bills to register with the same last three digits? ANSWER:P(2 bills to register)=1/10P3 1/(10!/7!), 1/(10*9*8)=.001389 (b) what is the probability that a person with 10 bills to register has at least 2 bills with the same last three digits? ANSWER:P=1/(10*10*10) =0.001 Answered by Andrei Volodin.
	The average of two averages		2002-05-22
		From RJ: in a class with 22 students, the average garde on an exam was 68%, in another class with 32 students, the average grade on the same exam was 78%, what was the overall for the two classes? round your answers to the nearest whole number. Answered by Leeanne Boehm.
	Un octogone		2002-05-21
		From Yves: Si j'ai un octogone ayant 8 pieds de diamètre,comment fais t'on pour trouver la mesure de un de ces cotés et quel est cette grandeur. Answered by Claude Tardif.
	A popular television game show		2002-05-19
		From Amrita: On a popular television game show, contestant must first answer a question by placing 4 given events in ascending or desending order in the quickest time. (a) if a contestant does not know how any of the events should be arranged, how many different ways could the question be answered? Answer: 4!= 24 (b)a contestant has to arrange the events that correspond to A, B, C, and D. one contestant is positive that event D follows directly after avent B, but does not know about the other s. how many different ways could this contestant arrange the letters A, B, C, and D, list the possibility Answer: which I didn't get Answered by Penny Nom.
	Probability and investment		2002-05-19
		From Bally: Investors do not invest all their money in the investment predicted to be the best beuause it is too risky. an investor holds shares in three independent cmpanies. company A, Company B, compnay C. an analyst predicts the probability of profit increases for each company as follows. Company A:0.70 Compamy B:0.50 Compnay C:0.65 (a) If the analyst's predictions are true, what is the probability that all three comapanies show a profit incresse? ANSWER: I try using vin diagram but it did'nt work, I dont know any other ways to solve this question (b) if the analyst's predictions are true, what is the probability that at least one comany shows a profit increase? Answered by Andrei Volodin.
	Conditional probability		2002-05-19
		From Manny: In a certain school, it is known that 80% of the students use the internet for school projects, 60% use e-mail on a regular basis, and 90% use the internet for school projects or for e-mail on a regular basis. a student from this school is selected at random Determine thge probability that the student used e-mail, given that the student used the internet for school projects. ANS: how can i solve this question by useing the vin diaagram Answered by Andrei Volodin.
	Flying with the wind		2002-05-19
		From SaraJean: It takes 6 hours for a plane to travel 720 km with a tail wind and 8 hours to make the return trip with a head wind. Find the air speed of the plane and the speed of the wind current. Answered by Penny Nom.
	How far apart are the transmitters?		2002-05-18
		From Jeff: A ship at sea is 70 miles from one transmitter and 130 miles from another. The measurement of the angle between the signals is 130 degrees. How far apart are the transmitters? Answered by Penny Nom.
	Find the angle measures		2002-05-18
		From Amanda: In triangle ABC; the measure of angle A is 20 degrees more than twice the angle B. The measure of angle C Is five times angle B. Find the angle measures. Answered by Penny Nom.
	Chord length		2002-05-17
		From Ashlie: How do you find the chord length of one section of a chord if you only have the diameter length and the other whole chord length. WV is the diameter and equals 16. XY is perpendicular to it, and equals 10. They intersect at pt. Z. I need to know what WZ equals. Please help! Answered by Penny Nom.
	On which assignment did I do better		2002-05-17
		From Denise: I have 2 writing assignments in class. The first assignment, which had a mean of 10 and a standard deviation of 2, I got a score of 12. The second assignment had a mean of 18 and an s.d. of 3, I got a 21. I need to know which assignment did I do better, relative to my classmates? Answered by Andrei Volodin.
	Sequences that agree on their first four terms		2002-05-16
		From Mike: Are there two formulas that define sequences that agree on their first four terms, but differ on the fifth term and all succeeding terms? Answered by Chris Fisher.
	Thank you gifts		2002-05-15
		From Navi: Children usually attend birthday parties where a thank you gift is given to the children who attent the party. a family likes to hand out books at thank-you gifts. (a) One child invited to the party is given 2 books as gift. if there was 15 different books to choose from, how many diffrent gifts were possible? Answeer: I did this way 15C2=105 (b) if the 15 books consisted of 8 nonfiction and 7 fiction, how many diffrent gifts were possible if at least 1 of 2 books were fiction? Answered by Penny Nom.
	Day care		2002-05-13
		From Sonam: In many familes, both parents work. as a result, there is increasing need for day care. data was collected; and in one year in Canada, approximately 32% of children aged 0 to 11 years were in day care for at least 20h per week. (a) what is the probability, in a random poll of 60 children form the age of 0 to 11, that more than 15 children are in day care at least 20 h per week? nearest tenth of one % ANSWER: P(children are in daycare at least 20h)= 60/60C14 = to the answer (b) what is the probability, in a random pool of 60 children that fewer than 20 are in day care at least 20 h per week? ANSWER: P= 20/60= 33.3% stay in day care for 20h per week, I dont know if these answers are right please help me out. Answered by Andrei Volodin.
	What is Calculus About?		2002-05-13
		From A student: I am a high school senior and have to write an essay answering the question "What is Calculus?" I need some ideas. Thanks Answered by Walter Whiteley.
	A game of dice		2002-05-13
		From Mika: To play a game a dice is rolled to see who plays first. four players are going to play the game. what is the probability that at least two people roll the same number? ANSWER: P(least 2 people roll the same #)=number of player/total outcome P = 4!/4C2 = 24/4C2 = 4 the answer is 40% Answered by Andrei Volodin.
	An award ceremony		2002-05-13
		From Mika: Five students are equally qualifide their school at an award ceremony. two students will be randomly chosen to go to the ceremony. (a) if Tony is one of the five student, what is the probability that he will be chosen? Ans: 2/5C2=0.2 which is 20% (b)Tony's friend, Allecia, who was also eligible to go, has been chosen. what is the Tony's probability of being chosen after he learns that allecica is going: Ans: 1/5C1=0.2 I think the answes are wrong please help me with these questions Answered by Andrei Volodin.
	Some algebra		2002-05-11
		From A student: /x - 2 ^4/x = 8 / = square root sign ^ = 4th root of x also, dividing 2x3 -3 -6x __________ 4 + 2x the 2x3 is 2x to the third Answered by Penny Nom.
	A ski trip		2002-05-10
		From Navi: A ski trip at the school has been arranged. there are 30 students that have paid for the trip and 6 parents that have volunteered to chaperone. to transport the students and parents easily, they are to be divided into two group. one group has 10 students and 2 parents, and the other group has 20 students and 4 parents. (a) How many different group of 10 students can be formed? ANSWER: (b) How many different groups consistinmg of 10 students and 2 parents are possible? ANSWER: (c) kelly is one of the students going on the ski trip, and kelly's mother volunteered to be one of the chaperones. kelly's mother would prefer to be in the smaller group and not in the same group as kelly. if this wish is honoured, how many ways can the smaller group and its chaperones be chosen? ANSWER: Answered by Harley Weston.
	The law of cosines and obtuse angles		2002-05-09
		From Bryant: The question that I am pondering is that I need to derive the law of cosines for a case in which angle C is an obtuse angle. Answered by Penny Nom.
	A rectangular marquee		2002-05-07
		From Alyaa: a marquee with rectangular sides on a square base with a flat roof is to be constructed from 250 meters square of canvas. find the maximum volume of the marquee. i find this topic so hard Answered by Harley Weston.
	Forming a committee		2002-05-06
		From Navi: A committee is to be formed to investigate what activites teenagers have available in small communities. the committee is to have 7 members, chosen randomly form interested community members. there are 10 parents, 5 teenagers, and 4 adult without children who have all expressed an interest in serving on the committee. what is the probability that the adults without children are all on the committee? Answered by Andrei Volodin and Penny Nom.
	Oven lights		2002-05-06
		From Manny: Q.A manufacturer of stoves has to buy oven lights from from two diffrent companies because one company alone cannot meet its demand. the manufacturer purchases 60% of the oven lighs from comany A and the rest form Company B. Past experiecnce shown that 1% of Company A's oven are defective oven and 2.5% of Company B's oven light are defective. Determine the probability that a defective oven light is supplied by company A. Answered by Andrei Volodin.
	How will I use calculus in my career?		2002-05-06
		From Meridith: How will I, hopefully a future secondary mathematics teacher, use calculus in my career if I'm not teaching calculus? Answered by Walter Whiteley.
	3 = -2x		2002-05-05
		From Timothy: My question is 3 = -2x How do I isolate the variable here? Answered by Penny Nom.
	A probability tree		2002-05-04
		From A student: Karl and Naomi roll three dice. Karl gives $10 to Naomi if the number 5 turns up once, twice or three times. Naomi gives Karl $3 in all other cases. A) construct the probability tree for this situation. B) Does Karl have an advantage in this game? Justify your answer. My problem is I am unfamiliar on how to draw this probability tree and seem to be having a lot of difficulties, when you have a chance please answer this math problem and get back to me with the results. Answered by Penny Nom.
	An identity(?)		2002-05-02
		From A student: prove identity sin 2x/1-sinx= secx+1/secx Answered by Paul Betts.
	8/13*26/27		2002-05-01
		From Arias: 8/13*26/27= Answered by Penny Nom.
	Square numbers		2002-05-01
		From Sally: Is one considered a square number? Answered by Penny Nom.
	oneths		2002-04-30
		From Logan: why are there tens-tenths hundreds-hudreths, but not oneths if that made no sense then how about this why does everything have two ways of saying things like tens and tenths but not a oneths Answered by Claude Tardif.
	Factor 12x^2 - 20x - 8		2002-04-30
		From Crystal: Factor Completely: 12x2 - 20x - 8 Answered by Penny Nom.
	The Dugout, Don's Basement, Cd Corner,...		2002-04-30
		From A student: The Dugout, Don's Basement, Cd Corner, Harry's Deli, Bill's Software, Anne's Footwear, and Joanne's House cleaning. The gift certificates are each in multiples of $5. There is a $100 range in the value of the gift certificates, which start at $25. The mean value of all seven gift certificates is $80, and the median and mode are both $70. The certificate from The Dugout is worth the most and the one from Joanne House cleaning is worth the least. The total value of the gift certificates from CD Corner, Harry's Deli, and Anne's Footwear is $270, but Anne's Footwear certificate is worth $50 more than the one from Harry's Deli. The Cd Corner gift certificate is equivalent to the mean for this group of three. What is the value of the gift certificates from each store? Answered by Penny Nom.
	What's the next term?		2002-04-29
		From A student: Find the nth term for the following: 1) 12, 30, 56, 90, 132 2) 6, 30, 84, 180, 330 3) 8, 15, 24, 35, 48 4) 10, 17, 26, 37, 50 5) 24, 40, 60, 84, 112 6) 24, 60, 120, 336, 504 Please show the FULL working out. Answered by Penny Nom.
	Trains and cracker boxes		2002-04-29
		From Lindsay: 1)Two trains are 250 miles apart on the same track heading towards eaxh other at 7AM- The first train travels at 55mph, the second at 75mph. At what time would they crash? 2)A cracker box measures 12 by 2 by 18 inches. The company wants to double the amount of crackers, but keep the shapes the same[similar] Find the new length[nearest tenth of an inch] Answered by Penny Nom.
	Conversion of units		2002-04-29
		From Matt: I am having trouble finding a workable equation for the following problem, particularly the conversion of two systems of measurement. The question states that there are 27 grams of salt in a kilogram of seawater. And it asks how many tonnes (1 tonne = 1000 kilograms) of salt are there in one cubic kilometer of ocean. It also says that the density of seawater is 1.1 g/cm3. What is the equation and how do I figure out how many kilograms there are in a cubic kilometre? Answered by Harley Weston.
	A 6,000 gallon tank		2002-04-28
		From Someone with a big tank: I was wondering if you can find out information about how much liquid fuel can fit in a 6,000 GAL. tank. Right now I do not have the exact dimensions of this tank but I will have it the 29th of April. Could you please E-mail me and let me know if you can answer this question after I have the correct specifications. Answered by Penny Nom.
	0/4 = ?		2002-04-28
		From Danielle: I am embarrased to be asking this question, but... is it possible to have a fraction with a zero? For example, 0/4. This does not make sense to me and I do not know what it would be representing, other than nothing! Is it proper to express such a fraction? Answered by Peny Nom.
	A triangular prism		2002-04-28
		From A student: Need the formula for the surface area of a triangular prisim? Answered by Penny Nom.
	a+b=10 and ab=40		2002-04-27
		From April: What two numbers add to ten and multiply to forty? (a+b=10, a*b=40) I think the answer includes radicals and/or imaginary numbers. Answered by Penny Nom.
	Designing a ballot		2002-04-26
		From Kelley: I want to design a ballot for four elections. Actually all the candidate races are on 1 ballot. I need to know how many different ballot styles would be needed for all of the candidates to be in each rotation an equal number of times. For example: A,B,C & D are running for mayor E,F,G & H are running for congress I,J & K are running for senate L,M & N are running for governor They are all on the same ballot. But in each race their name (for instance A) has to be in the #1 rotation, #2 rotation, #3 rotation, and #4 rotation for his race on this ballot an equal number of times as B,C and D. The same goes for the other candidates for their perspective races. How many total ballot styles will there be? Answered by Penny Nom.
	Triangular numbers		2002-04-26
		From Anika: Can you please tell me what a triangular number is? Answered by Penny Nom.
	Functions and relations		2002-04-25
		From Erin: Here's a few math problems that might drive a person insane ;) If 2f(x) - 3f(1/x) = x^2 what is f(2)? What are the domain and range of the following relations? x^2 - 4y^2 = 25 4x^2 + 9y^2 = 36 The port of Swan Harbor is 200km away from Merry Town Inlet on a bearing of N50E from Merry Town. A ship leaves Merry Town at 8am and sails N15W at 15 km/h. At the same time, a second ship leaves Swan Harbour on a course of S80W at 20km/hour. How close, to the nearest km, are the two ships at 13:00? Prove the identity. 1+sinx + cosx/ 1-sinx + cosx = 1+sinx / cosx Answered by Penny Nom.
	How much of that total is G.S.T?		2002-04-24
		From Darlene: If I have $1700.00 how much of that total is G.S.T? not 1700.00 + gst ____ + _____ gst = 1700.00 Answered by Patrick Maidorn.
	Arithmetic progressions		2002-04-24
		From David: I have been searching everywhere for the formula to mathamatical progression. Answered by Penny Nom.
	An Olympiad problem		2002-04-23
		From Aurora: I wrote a mathematical Olympiad the other day and there was one question that I could not work out. The question was If ab = 1, bc =2, cd =3, de =4 and ea = 6, what does a + b + c + d +e = It was a multiple choice and the answers were : 43/6; 47/6; 49/6; 53/6; 61/6 The correct answer was 61/6, but how can do you get to that answer? Answered by Anrei Volodin.
	A test drive		2002-04-23
		From Jennie: At 9 A.M. a test car driving at a constant speed passes a marker 50 miles from it's starting point. At noon the car is about 130 miles from the marker. If the test drive ends at 1:30 P.M., how far will the car be from its starting point? Answered by Penny Nom.
	25m = 100		2002-04-22
		From Megan: If 25m = 100, Then m equals what number? Answered by Penny Nom.
	Lines of symmetry		2002-04-22
		From Cindie: How many lines of symmetry do the following figures contain? trapezoid: rhombus: hexagon: pentagon: Answered by Walter Whiteley.
	Problem solving		2002-04-20
		From Kathy: Zachary wanted to run the shore-to shore marathon next month, a 26 mile race from one side of the island where he lived to the other. He decided to work up to 26 miles by running five days a week for the next five weeks. Each day he'd run one mile longer than he did the day before, except for the first day of the week, when he'd run the same number of miles he ran on the last day of the previous week. He wanted his last two practice runs to be 26 and 27 miles long. How many miles would he have to run on his first practice run? A school just bought a new set of encyclopedias. The front and back covers are 1/8 inch thick, and the pages are 1/100 inch thick (in other words, there are 100 pages per inch). the 26 volume set has a total of 5,250 pages. If you assume there is no extra space left between books, then ......... What length of bookshelf will the encyclopedias take up? Answered by Penny Nom.
	Solve for x		2002-04-20
		From A student: solve for x. c-x 2x+b ----- = -------- a c Answered by Peny Nom.
	Cubic yards		2002-04-20
		From Pat: I HAVE AN AREA 10'x6'I WOULD LIKE TO PUT LOAM ON IT 5" DEEP HOW MANY CUBIC YARDS OF LOAM DO I NEED? Answered by Harley Weston.
	An augmented matrix		2002-04-20
		From A student: Hi my math teacher asked us to solve an augmented matrix. I am in twelfth grade and need help. The book we are working on is college algebra. Here it is a+2b+c=0 2a+5b+4c=-1 a-b-9c=-5 Answered by Penny Nom.
	Solving for x		2002-04-19
		From Susan: I'm having a little trouble solving these equations for x. I can't seem to separate x fully from the other numbers. Please help! Here are the problems: (2x-1)/(x-2)(x 2+3) = 0 and y/(x+1)=z/x Answered by Penny Nom.
	Moving a triangle		2002-04-18
		From A student: find the verticles of a triangle after it is translated 2 units to the left and then is reflected across the graph of y=x+2. The original verticles of the triangle are (2,0), (3,2), and (6,2). Answered by Peny Nom.
	How many different account numbers are possible?		2002-04-18
		From Andrene: how many different account numbers are possible if the account numbers consist of a letter of the alphabet, followed by five numerical digits, and followed by another letter. Answered by Penny Nom.
	Arc length		2002-04-17
		From Vix: Find the point on the curve r(t)=(12sint)i-(12cost)j+5tk at a distance 13pi units along the curve from the point (0,-12,0) when t=0 in the direction opposite to the direction of increasing arc length. Answered by Harley Weston.
	Ratios		2002-04-17
		From A student: Medication is givin at 1cc. per 20 pounds of body weight. A dog weighs 16 pounds how many ccs. of medication does the dog get? Dr. Lee wants you to prepare 1000 ml. of a 10% dextrose solution in lactaed ringers for diuresis or a patient you have a 1 L bag of lactated ringers and 500 ml of 50% dextrose for injection. How would you prpare the solution? Answered by Penny Nom.
	Related rates		2002-04-17
		From Molly: A tanker spilled 30 ft cubed of chemicals into a river, causing a circular slick whose area is expanding while its thickness is decreasing. If the radius of the slick expands at the rate of 1 foot per hour, how fast is them thickness of the slick decreasing when the area is 100 feet squared? Answered by Penny Nom.
	Two algebra problems		2002-04-14
		From Ashley: Question 1: For all values of a, let < a > be defined as < a > = 4a - 4 . Which of the following equals < 6 > - < 5 >? A: < 2 > B: < 3 > C: < 4 > D: < 5 > E: < 6 > Question 2: If 5n + p = 3 and 2m - 10n = 2, what is the value of m + p? Answered by Penny Nom.
	A polynomial		2002-04-14
		From A student: A polynomial function is described by the following conditions: f(x) has two real zeros at x= -2 and x= 1, each of multiplicity 2 f(x) has two complex zeros as x goes to -infinity, f(x) goes to +infinity as x goes to +infinity, f(x) goes to +infinity f(x) has a y-intercept at (0,2) Sketch a polynomial function that satisfies the above conditions. Write an equation for function f(x) Write another function g(x) that also satisfies the above parameters. Answered by Penny Nom.
	How many gallons of water in a cubic foot?		2002-04-14
		From Richard: I am tring to find out how many gallons of water in a cubic foot. Answered by Penny Nom.
	The vertex of a cone		2002-04-13
		From Callie: Does a cone have a vertex? Answered by Penny Nom.
	The square root of four		2002-04-13
		From Frank: In a recent quiz we where asked the square root of four. The quizmaster gave the answer as not only 2 but also -2. Being pedantic I queried this. Although -2 squared is 4, does it follow that the root of 4 is -2 Can you enlighten us? Answered by Claude Tardif and Penny Nom.
	The bleep test		2002-04-13
		From Lorraine: I am currently undergoing training and have asked about a fitness test called the bleep test. The bleep test involves running continuously between two points that are 20m apart. These runs are done in time to a pre-recorded bleep sounds on a pre-recorded audio cassette. The time between the recorded bleeps decrease after each minute. I would like to do my own personal version for training but I have to work out the following before doing this: I need to find out the time in-between the beeps at least for the first level so I can work out the difference for the other levels: The information given to me for the first level is : A 20 meter run at 8.5km/hr (how long would it take?) Please let me know if there is any way in working out this query with the information given. Answered by Leeanne Boehm.
	Calculate profit		2002-04-13
		From Allison: If I sell something for $75; and my cost is $40, I make $35 profit. How do I calculate the profit percent I made on that transaction? Answered by Penny Nom.
	Diagonals in a polygon		2002-04-10
		From Murray: If you have a regular polygon with n sides and you draw all (n-3)n/2 diagonals how many intersection will they form with each other and how many sections will they devide the polygon into. Answered by Caude Tardif and Chris Fisher.
	n +1, n+2, n+3, and n+4 are all composite		2002-04-09
		From Jonathan: Find the small integer n such that n +1, n+2, n+3, and n+4 are all composite Answered by Penny Nom.
	The Proof in the Pudding		2002-04-09
		From A student: The host at a party turned to a guest and said, "I have three daughters and I will tell you how old they are. The product of their ages is 72. The sum of their ages is my house number. How old is each?" The guest rushed to the door, looked at the house number, and informed the host that he needed more information. The host then added, "The oldest likes strawberry pudding." The guest then announced the ages of the three girls. What are the ages of the three daughters? Answered by Claude Tardif.
	Sodding the yard		2002-04-08
		From Craig: my parents want to lay sod in our back yard. the sod cost $2.00 per square foot. The size of our yard is 20x20 and 26x41 Answered by Penny Nom.
	Area of a triangle		2002-04-07
		From Puzzled: What is the surface area of a triangle 13 ft x 13 ft x 18 ft? Answered by Penny Nom.
	3/4n-6=12		2002-04-07
		From Diane: I am in 6th grade advanced math and I just started Algebra. My teacher tries to explain it to me but I just can't get it. I am having difficulty understanding it. Please HELP!!! I will type a problem, if you could answer it and show your work so i can understand it that would be great. Please explain in simple terms. here is a couple problems I am having trouble with, PROBLEM #1 3/4n-6=12 Answered by Penny Nom.
	Composition of functions		2002-04-06
		From Yvonne: In our new text book, the following question occurs: State the domain and range of g(f(x))given that f(x) = -x2 - 4 and g(x) = sqrt(x) The range of f(x), x<=-4, is the domain of g(x). BUT, there is no solution in the Real numbers for g(f(x))= sqrt(-x2 - 4). In the solutions it says that this is not a function and therefore does not have a domain or range. Is it a relation? Is it anything? Answered by Claude Tardif.
	Pairs of equations		2002-04-04
		From A student: high school level student is asking y=4x x=-4y x+y=5 3x+2y=20 y=x-1 3x-y=4 x+y=3 2x-3y=-9 x+5y=4 3x+15y=-1 . . . Answered by Penny Nom.
	Two triangles		2002-04-03
		From Scott: Consider 2 triangles: Triangle PMB and Triangle PLA. Triangle PLA is contained within Triangle PMB. Side LA is parallel to Side MB. Point L is located on Side PM. Point A is located on Side PB. If the ratio PL:LM = 5, then what is PB:PA ?? Answered by harley Weston.
	Take It!		2002-04-03
		From Bryan: You are playing Take It! for $180,00 with a total stranger. There are 180 identical balls in a big vase. Each player in his turn, reaches into the vase and pulls out 1,5,or8 balls. These balls are discarded. The player who takes the last ball from the vase wins the $180,000. A flip of the coin determines that you will go first. Are you glad? How many will you take out on the first move, and how will you proceed to win the prize? Answered by Claude Tardif.
	Common fractions to decimal fractions		2002-04-02
		From Natalie: My questions are: "how can I change 23/60 into a decimal. and give my answer to 2dp."?????????? 2nd question:for each of these pairs, which is bigger? 4/7 or 36%____________ 3/11or 0.29____________ 14/24 or 0.57___________ Answered by Penny Nom.
	Pascal's Triangle		2002-04-02
		From Brian: It's about (a+b)x. I remember there a triangle with numbers to remember for a faster solution. Can you please teach me? Answered by Penny Nom.
	If you conect all the vertices of a regular n-gon...		2002-04-01
		From Murray: If you conect all the vertices of a regular n-gon with lines you will have (n-3)(n/2) lines inside the polygon. I want to find out how many sections these lines divide the polygon into and how many intersections they have with each other. Answered by Claude Tardif.
	Area of an octagon		2002-04-01
		From Someone: What is the actual square footage of a 12' octagon? Answered by Penny Nom.
	All four eights in three consecutive hands		2002-04-01
		From Blair: What are the odds against the same person holding all four eights in three consecutive hands. Answered by Brian Alspach.
	Meg's biscuits		2002-03-29
		From Tami: Meg's biscuits recipe calls for 4 cups of flour for every 1.5 cups of milk. If Meg uses 6 cups of flour, how many cups of milk will she need? Answered by Penny Nom.
	The reciprocal of a decimal mixed number		2002-03-29
		From A student: How do I find the reciprocal of a decimal mixed number? Answered by Penny Nom.
	Some 5 card hands		2002-03-28
		From A student: From a standard deck of cards how many 5 card hands are possible consisting of a. exactly 4 hearts b. two cards of one kind and three of another(like a full house). Answered by Penny Nom.
	100 from four 9's		2002-03-27
		From A student: My teacher gave us a math problem to try and figure out and I am stumped. The problem was this.... by only using four nines, how can you get an answer of 100? You can add, subtract, multiply or divide...anything you need to do ,but you can only use four nines. Answered by Leeanne Boehm.
	If the matrix A is inverible and AB =AC, then B = C		2002-03-27
		From Vikki: i hope you can help i am soooo stuck here goes: a) A= 0 1 B= 1 1 c= 2 5 0 2 3 4 3 4 A,B and c are matrices Evaluate AB and Ac (which I can do) then b) I need to prove that if the matrix A is inverible and AB =AC, then B = C. Why does this not contradict what happened in part a)? Answered by Leeanne Boehm.
	Cube roots		2002-03-26
		From Kathy: My son is in 4th grade and needs to simplify the cube roots of 216, 512 and 64. How does he do this with a regular calculator or without? Answered by Penny Nom.
	A triangle in a circle of radius 6		2002-03-26
		From Marko: In a circle of radius 6, a triangle PQR is drawn having QR = 8 and PQ = 10. Determine the length of PR Answered by Chris Fisher.
	A lottery question		2002-03-25
		From Noel: I want to take all numbers in a Lotto game from 1 to 45 and ditribute them between 9 boxes each containing 5 numbers. Each number is used only once. What is the probability that I derive the correct combination of 5 numbers in the draw? What is the probability if I take a systems game and now distribute 9 numbers into each of 5 boxes? Once again, the numbers are used only once. Can you explain what formulae are used and how the answer is derived? Is this a distribution or combination problem? Or is it a combination of both distribution and combination? Answered by Andrei Volodin and Penny Nom.
	Unit fractions		2002-03-23
		From Laura: Write 1/2 as the sum of ten different unit fractions. Answered by Claude Tardif.
	A hamburger and a soft drink		2002-03-23
		From A student: A GROUP OF FRIENDS WENT OUT TO LUNCH. EACH BROUGHT A HAMBURGER AND A SOFT DRINK. TOGETHER A HAMBURGER AND A SOFT DRINK COST MORE THAN A DOLLAR. THE TOTAL COST FOR THE GROUP WAS $17.81. THERE WAS NO TAX OR TIP INCLUDED. IF A HAMBUGER COSTS 2 CENT MORE THAN TWICE A SODA, FIND THE COST OF THE HAMBURGER. Answered by Leeanne Boehm.
	A probability problem		2002-03-23
		From Kate: If I have a spinner and then spinner has the numbers 1,2,3,4 on it and it is spun 3 times, what is the probability that the spinner will stop on 4,3,and 1 ? In that order? Answered by Leeanne Boehm.
	A trigonometric identity		2002-03-22
		From Debby: I am stuck on a problem and wondering if you can help?? It is: Prove the following: sec2(X)+csc2(X) = sec2(X)csc2(X) Answered by Harley Weston.
	Mr. Byrd's drive to work		2002-03-22
		From Mr. Bollen: Mr. Byrd leaves his house at 7:00am to go to work. If he drives 40 mph he will arrive 3 minutes late and if he drives 60mph he arrives 3 minutes early. At what speed will Mr. Byrd have to drive in order arrive exactly on time. Please describe how you arrived at your answer. Answered by Claude Tardif and Penny Nom.
	Range of values for standard deviation		2002-03-22
		From Susan: What is the range of values for standard deviation? Is it between 0 and +3? Is it between +1 and +3? Answered by Andrei Volodin.
	What fraction of the world's motor vehicles are built in Canada?		2002-03-20
		From A student: About 1/4 of the world's motor vehicles is built in Canada or the United States. About 1/5 of the world's motor vehicles are built in the United States. What fraction of the world's motor vehicles are built in Canada? Answered by Claude Tardif.
	Adding algebraic fractions		2002-03-20
		From Dolores: I get totally confused with this problem. I get confused with the getting the lowest terms. 4/x-5 + -2/x -10/x^2-5x Answered by Penny Nom.
	A cone in 3 space		2002-03-20
		From Matthew: Let C in R3 be the cone defined by x2 + y2 - z2 = 0 (A) Let P be the plane described by x + 2z = 1 (i) Find a description of P in terms of two parameters s and t . . . Answered by Walter Whiteley.
	F = -3 + 3		2002-03-19
		From Jessica: F= -3 + 3 WHAT IS F????? Answered by Penny Nom.
	A set of points in space		2002-03-18
		From Victoria: Describe the given set with a single equation or a pair of equations: The set of points in space that lie 2 units from the point(0,0,1) and at the same time 2 units from the point (0,0,-1). Answered by Penny Nom.
	24x^4 + 3x		2002-03-18
		From gary: 24x 4 + 3x Answered by Penny Nom.
	Interest owing		2002-03-17
		From Dean: I am an investor. If I lend to someone on January 1, 1999, $1000 to be paid back interest at 2% per year (simple interest, ie not compounded), and on July 15, 1999, I lend the same person $1,500 more (total loan is now $2,500) but at 18%, and once again on October 15, 1999, I lend to the same person another $1,500, and the person pays me back the principle($4,000) and interest on January 1,2001: What is the total (principle plus interest) due me? The tougher question is: what was my blended rate of return on my total outlay of money? Is there a formula you can give me so that I can perform my own calculations? Answered by Harley Weston.
	Combinations?		2002-03-16
		From Sara: A combination lock has three dials numbered 0 - 9. Give a mathematical reason why "combination" is a bad name for this type of lock. Answered by Penny Nom and Chris Fisher.
	How much olive oil?		2002-03-15
		From Annie: Joe used 1/3 cup of olive oil, which was 3/4 of the amount that he had. How much olive oil did he have! Answered by Penny Nom.
	Testing a hypothesis		2002-03-14
		From A student: A large distriutor of cosmetics has kept his outstanding accounts receivable to a mean age of 18 days over the past year. This average is considered a standard by which to measure the efficiency of the credit and collections department. Management wishes to check if receivables in the current month is over standard and will do this at a significance level of 0.50. A random sample of 100 accounts yields an average of 20 days with a standard deviation of 9 days. what should management conclude? Answered by Andrei Volodin.
	The square root of i		2002-03-14
		From Arlene: what is the square root of i, if i=x+yi? what is the square root of 1-i? i'm getting problems like these in which I do not understand. Answered by Harley Weston.
	3 5/8 and 2 1/4		2002-03-13
		From Shirley: 3 5/8 and 2 1/4 what is the percentage of 2 1/4 to 3 5/8. Answered by Penny Nom.
	15 miles at 13 miles per hour		2002-03-12
		From Rich: If I were traveling 15 miles at 13 miles per hour how long will it take? Answered by Penny Nom.
	My 1978 Chevy has a 350 cubic inch engine		2002-03-11
		From Sharon: If my 1978 Chevy has a 350 cubic inch engine, about what size engine would that be in liter? Answered by Penny Nom.
	x and y-intercepts		2002-03-10
		From A student: I have the problem- f(x)= X-5/X2+X-6 and I have to find the vertical asymtope, horizontal asymtope, x-intercept, and y-intercept. And graph the problem. I am having problems finding the y-intercept. Answered by Harley Weston.
	The best time to teach math		2002-03-10
		From West: My name is West. I teach 4th grade. I would like to know if there is any research which tells about the best time to teach math. Should it be taught in the a.m. or p.m. Answered by Walter Whiteley.
	Multiplying decimals		2002-03-10
		From Kaitlin: I just recently had a test on multiplying decimals and I did not do really well on it. Only 5 kids out of 19 got a passing grade. My teacher says that she will give us a different test and we can take it again, but I'm still not sure of it. My teacher has taught me a lot and she had done a wonderful job of it but I'm just confused with where to put the decimals and stuff like that. I have a math practice workbook that I do for fun and they have nothing on decimals in it. I have checked on websites to try to find worksheets but I really couldn't find a good one. Can you please help me either give me some tips or clues or send me a worksheet. Answered by Penny Nom.
	The isosceles triangle of smallest area		2002-03-08
		From Lettie: can you find the isosceles triangle of smallest area that circumscribes a circle of radius of one? Answered by Walter Whiteley.
	Percentage difference		2002-03-08
		From Tedd: Can you give me the formulas for calculating percentage differences between two numbers? For example: if the first number is 10 and the second number is 15, then the second number is 50% larger than the first number. However, the formula to calculate that percentage won't work if the first number is greater than the second number as in the following example: The first number is 15 and the second number is 10, with the second number being 33.3% less than the first number. Or maybe I'm mistaken and the same formula will work in both situations. Answered by Penny Nom.
	Factor completely		2002-03-07
		From Taylor: I'm supposed to completely factor this but I don't know what to do with all the variables. a3b5 - a2b5 - 12ab5. Does it have anything to do with b5 being a common factor or am I completely off? Answered by Penny Nom.
	A sequence		2002-03-07
		From Caroline: hi, here is the problem, 1 11 21 1211 111221 _ _ 2_ _ _ we can't get the sequence of the last line ,with the 3rd number being 2,thanks Answered by Walter Whiteley.
	The square root of 2		2002-03-05
		From Roger: Does two (2) have a square root or do the numbers just keep going? Are there any other numbers that behave like two when it comes to extracting the square root? Answered by Penny Nom.
	A circular wading pool		2002-03-04
		From Patrick: The community of melfort is planning to build a circular wading pool in the park. The pool will cover an area of 1000m2. The building committee has decided to put a 5m cement pad around it. How much additional area will the cement pad take up? Answered by Harley Weston.
	The slope of a tangent line		2002-03-04
		From Ridley: Suppose a function f(x) has the line 3x+4y=2 as its tangent line at x=5. Find f'(5). Answered by Harley Weston.
	Percentage		2002-03-03
		From Nathan: I have two questions: 25% of what number is 195? 42 is what percent of 112? Answered by Penny Nom.
	Mixed numbers, whole numbers and improper fractions which are less than 2.		2002-03-03
		From Dawn: Change each mixed number to a whole number and an improper fraction which is less than 2. 3 1/2 = 2 / Answered by Penny Nom.
	What number am I?		2002-03-03
		From Samantha: I am an even number that has more ones than tens. My thousands digit is the quotient of 9 divided by 3 and my tens digit is the sum of 3 and 3. I have no hundreds. What number am I?......Please answer this for me...The answer I come up with is 3,060...Is this right?.. Answered by Penny Nom.
	The median with ties		2002-02-27
		From Marcel: What, exactly, is the proper way to determine the median of a set of numbers when doubles or triples of a number are part of that set? Do the doubles count as two and the triples three, or does each count only as one toward determining the median. Answered by Harley Wston.
	Two circles inscribed in a rectangle		2002-02-27
		From Amina: Given a rectangle with dimensions L=6, H=5. Two circles are inscribed such that they touch each other(circles are adjacent to each other) and also their circumferences touch 2 sides of the rectangle. One of the circles has radius=4. Find the radius of the other circle. Answered by Penny Nom.
	Simplify this expression		2002-02-26
		From Francine: 2X power 5 Y power 3 times 18 X power -5 Y power -3 divided by X power 1/3 Y power 1/4. I came up with 36 ---------- X 1/3 Y 1/4 The book says 36 x1/3 y1/4. I don't get it. Answered by Penny Nom.
	sin 2x = cos 3x		2002-02-25
		From Allan: solve: sin 2x = cos 3x Primary question: how do you handle the cos 3x? Answered by Paul Betts and Chris Fisher.
	The substitution method		2002-02-24
		From Joe: whats the answer to this question? 3x+y=11 x+2y=-3 its substitution method i am having alot of trouble figuring it out. send the answer as soon as possible. thank you Answered by Penny Nom.
	A hat of a different color		2002-02-24
		From Kirstin: A teacher made a deal with 3 of his students. He said that if you can guess what color hat you have on your head without looking, I will pass you. There were 2 red hats and 3 blue hats. The deal worked like this: The three students would close there eyes, and the teacher would put a hat on each of their heads and then hide the other 2. Then one at a time, the students would open their eyes and try to figure out what color hat was on their head. The student could guess or pass. This is what happened when they put their deal to the test: A boy named Arturo was first and opened his eyes but wasn't sure so he passed so he didn't get it wrong. Belicia was next and she passed too because she wasn't sure. Also she thought about the fact that Arturo didn't know. Carletta was last and without even opening her eyes, she knew for sure what color hat she was wearing and her answer was right. So i have to figure out what color hat she's wearing for sure. Answered by Claude Tardif.
	350 students took the math A exam		2002-02-22
		From Jim: at a high school 350 students took the math A exam. 82% passed the test. 40 students that failed the exam in june, took the exam in August. 70% of this group passed the August test. How many of the original 350 students have passed the exam before september? Answered by Paul Betts and Penny Nom.
	1,4,27,____,_____46656		2002-02-21
		From Brenda: 1,4,27,____,_____46656..... please find the fourth and fifth numbers in this sequence. Answered by Penny Nom.
	Alfredos house number		2002-02-21
		From Aunt Patty: Alfredos house number is between 20 and 35. The sum of the digits is less than 5. If you subtract 1 from it you would get a multiple of 3. If you add three, you get a multiple of 5. What is Alfredos house number. Answered by Penny Nom.
	Proof by induction		2002-02-20
		From Tamaswati: How do I prove the assertion that "the determinant of an upper triangular matrix is the product of the diagonal entries" by mathematical induction? (Before I check this assertion for a few values of n how do I rephrase the assertion slightly so that n appears explicitly in the assertion?) Answered by Penny Nom.
	An octagon-shaped deck		2002-02-20
		From An instructor: How can you solve for finding the side measurements of an octagon-shaped deck that is 10 feet long and 10 feet wide. Answered by Penny Nom.
	When will the calendar be the same as 2002?		2002-02-20
		From John: When will the calendar be the same as 2002? I know the answer is 2013, but I don't know how to answer this mathematically, or if it is possible to do so. This is a ninth grade level algebra question my daughter received from her teacher. Any ideas? Answered by Chris Fisher, Patrick Maidorn and Penny Nom.
	Shipping charges		2002-02-19
		From Sohail: A mail order company charges a fixed fee for shipping merchandise that weighs 1 pound or less, plus an additional fee for each pound over 1 pound. If there shipping charge for 5 pounds is $4.80, and for 12 pounds is $6.20, find the fixed fee and the additional fee. Answered by Penny Nom.
	A farmer takes 100 animals to the market to sell.		2002-02-19
		From Ann: A farmer takes 100 animals to the market to sell. All are sold and $100 is earned. The prices were $5.00 per cow, $1.00 per sheep and $.05 per pig. At least one of each kind of animal was sold. How many of each kind of animal did the farmer take to market? Answered by Penny Nom.
	Sampling distributions		2002-02-18
		From A student: given: n = 40, standard deviation is not known, population of individual observations not normal. does the central limit theorem apply in this case? why or why not? for an estimation problem, list two ways of reducing the magnitude of sampling error? What will happen to the magnitude of sampling error if the confidence level is raised all other things remaining the same? justify your answer? Answered by Harley Weston.
	Double square roots		2002-02-17
		From Ali: i have a question about how to do double square roots with variables and powers. example : v/"" v/"" 81y8 Answered by Harley Weston.
	A degree 5 polynomial		2002-02-17
		From Carla: Write an equation for a polynomial of degree 5 given the following zeros: -7+3i, -2+sqrt(13), 6 Answered by Penny Nom.
	Can the standard deviation ever = 0?		2002-02-16
		From Karen: If given a class of 30 people who take a test with a mean of 80. Can the standard deviation ever = 0? If so, why? Answered by Penny Nom.
	Diameter of a pipe		2002-02-16
		From Landry: I am trying to calculate the dia. of a pipe 60 inches long that will hold a gallon of water. What is the formula? Answered by Penny Nom.
	The perimeter of an ellipse		2002-02-14
		From Harry: I am planning to build a coffe table with an ellipse of 24x36 for the top. I wish to decorate the edge and need to know the lenght of the perimeter for lay out purposes. Is there an easy way to approximate this figure with out using intergal calculus? Answered by Penny Nom.
	Nets for pyramids		2002-02-14
		From Michelle: I want to have my students create nets for pyramids and I need to know how to find the correct range of degrees for the interior congruent angles of the isosceles triangular faces. For example, I know for a square-based pyramid that 77 degrees will work; however, I know other angle measures will also work. I'm just not sure how to find the minimum degree measure to have the net actually "work". I'm assuming the maximum would be 89 degrees, although that would make for a very tall pyramid. Answered by Penny Nom.
	36 is 20% less than _____?		2002-02-13
		From Lori: 36 is 20% less than _____? Answered by Walter Whiteley.
	A man and his wife walk up a moving escalator		2002-02-13
		From Monty: A man and his wife walk up a moving escalator. The man walks twice as fast as his wife. When he arrives at the top, he has taken 28 steps. When she arrives at the top, she has taken 21 steps. How many steps are visible in the escalator at any one time. Answered by Peeny Nom and Claude Tardif.
	What is 20 to the thousandth power?		2002-02-12
		From Kristi: What is 20 to the thousandth power? Answered by Paul Betts.
	Three bugs on a line		2002-02-12
		From Murray: Three bugs are crawling on the coordinate plane. They move one at a time, and each bug will only crawl in a direction parallel to the line joining the other two. If the bugs start out at (0,0), (3,0), and (0,3), is it possible that after some time the first bug will end up back where it started, while the other two bugs switch places? Can the three bugs end up at (1,2), (2,5), and (-2,3)? AND A single peg is placed at the bottom left-hand corner of a grid that extends infinitely far up and to the right. You play a game in which you are allowed to make the following move: if the hole immediately above and the hole immediately to the right of a peg are both empty, you can remove the existing peg and place pegs in those two holes instead. Show that, no matter how you move, you can never remove all the pegs from the 3-by-3 square at the bottom left-hand corner of the grid. (b) Is it possible to remove all the pegs from the six holes closest to the bottom left-hand corner of the grid (the region indicated in the picture below)? Answered by Claude Tardif.
	The slopes of the sides of the Great Pyramid		2002-02-09
		From Christina: The Great Pyramid is the largest of the Egyptian pryamids. When it was built, it was 481 feet tall and had a square base with 755-foot sides. The pyramid has two different slopes-one along its sides and the other along its edges. Which slope is steeper? Answered by Penny Nom.
	The number of hidden cubes		2002-02-05
		From Katie: This problem is about finding the number of cubes visible and hidden in a cube. In a cube that is 3x3, 19 cubes can be seen. 8 are hidden. In a cube that is 4x4, 37 cubes can be seen. 27 are hidden. In a cube that is 5x5, 61 cubes can be seen. 64 are hidden. In a cube that is 6x6, 91 cubes can be seen. 125 are hidden. The question is: Explain how you could find the number of small cubes that are visible and hidden in a cube of any size. Answered by Paul Betts and Penny Nom.
	Parabolas		2002-02-03
		From Kuang: -Who is credited for working with or studying the Parabola? -What is a conic section? -What does a parabola look like? -How is a parabola formed? -Where and how are parabolas used today in the real world? Answered by Harley Weston.
	Number conversions and averages		2002-02-03
		From A student: A table has the measurements of 1.6m by 2m, how much material is needed to cover table? I converted to cm then multiplied but got an answer of 32000cm ,so I divide by 100 to get to metres - the answer was 320 which I know is wrong - please explain!! Also I need to explain in my own words what an 'average' is and I am struggling. Answered by Penny Nom.
	Square arrangements of clovers		2002-02-03
		From Cassie: Clyde had a strange fascination with numbers. One day he decided to mount his 4 leaf clover collection in groups of square numbers.he took a long piece of butcher paper and glue and began this arduous task.There was 1 clover,4 clovers.and then 9 clovers in the third set. what would be in the seventh set of 4 leaf clovers? Answered by Penny Nom.
	Zeta[2]=(Pi2)/6		2002-02-02
		From alex: Can you please tell me a proof that Zeta[2]=(Pi2)/6 Answered by Chris Fisher.
	I am a fraction		2002-02-01
		From Anthony: I am a fraction that is greater than 1 but less than 2. The sum of my numerator and denominator is 11. My denominator subtracted from my numerator is 1. What fraction am I? Answered by Paul Betts.
	The Euclidean Algorithm		2002-01-31
		From Murray: Can you please explain to me why the euclidean algorithm works? Answered by Penny Nom.
	Baseball and sit ups		2002-01-31
		From A student: A baseball team won 8 more games than it lost. If it played 56 games, how many games did it win? On the first day of practice, Paul did 3 sit ups. On the second day he did 5, and on the the third day he did 8, and on the fourth day he did 12. If this pattern continued, how many sit-ups did ihe do on the sixth day of practice? Answered by Penny Nom.
	The size of a lot		2002-01-26
		From Claudia: I own a piece of property that I need to know the square feet for assessment purposes. The figure they came up with is wrong. They measured from one point to another and halved the sums but that means I own the cul de sac and we don't. My lot is 55 feet wide and one side is 108.96 feet and the other side is 146.04 that extends all the way to a circle. The front of the lot on the cul de sac is stated on the survey like this. 78.21 feet where R=40 feet. This large arc is taken off the size of our land. How many square feet is our lot. Answered by Harley Weston.
	Logico mathematical knowledge		2002-01-23
		From A teacher: How does young children's logico mathematical knowledge develop? Answered by Walter Whitely.
	Adding algebraic fractions		2002-01-23
		From Francine: Hello, I've come up with an answer for the following problem but it's not the same as the book's answer. However, the book has a lot of mistakes in it and I don't know if I'm doing it properly or not. Your help would be soooo appreciated. It's driving me crazy.The problem is: 2 + 3 + 4 --------- + --------- + ---------- (x-1)^3 (x-1)^2 (x-1) [(x-1)^3 is (x-1) to power of 3 etc.] Answered by Penny Nom.
	Some trig problems		2002-01-22
		From Grant: Solve each problem for theta(there is no sign on my computer)for 0 is less than or equal to theta which is less less than 360 2cosx-1=0 cosx=1/2 Anwser 60,300 tanx-2sinxtanx=0 tanx(-2sin+1)=0 (factor ?) tanx=0 and sin= 1/2 (solve from there?) 2sinx-cscx=0 2sinx-1/sinx=0 3sinx-1=0 3sinx=1/3(?) 4cos(2x)+2cosx= -1 8cosx+2cosx+1=0 10cosx+1=0 10cosx= -1/10 (?) cos(2x-30)=1/2 cos2x-cos30=1/2 cos2x-cos30-1/2=0 i don`t know what to do know Sinx+cosx=0 Square both sides? Answered by Claude Tardif.
	Miles and kilometers		2002-01-22
		From Dennis: I'm in the middle of purchasng a vehicle and it was built in Canada. Therefore it is in kilometers and not in miles. I forgot how many kilometers are in a mile. It registers as 183,049 kilometers. Answered by Penny Nom and Judi McDonald.
	Normal distribution		2002-01-21
		From Danielle: A teacher gave a test on which the students' marks were normally distributed, but the results were pathetic. The mean was 52% and the standart deviation was 12%. The teacher decided that the top 10% of the students should get A's, the next 20% should get B's, the next 40% should get C's, the next 20% should get D's, and the bottom 10% should get F's. To the nearest percent, what are the cutoff marks that will result in an A, B, C, D, and F? Answered by Penny Nom.
	Successive differences		2002-01-20
		From Linsey: what is the rule for working out the formula for a sequence with three lines of difference? eg. 1, 3, 7, 15, 29 1st line differences: 2, 4, 8, 14 2nd line differences: 2, 4, 6 3rd line differences: 2, 2 Answered by Penny Nom.
	Rolling 5 sevens before rolling a six or an eight		2002-01-20
		From Tony: When rolling 2 dice, what is the probability of rolling 5 sevens before rolling a six or an eight? Answered by Andrei Volodin and Penny Nom.
	The distance across a circle		2002-01-18
		From Douglas: If you know how far around a circle is (say earth) 25000 miles how do you calculate the distance across? Answered by Penny Nom.
	Making 24		2002-01-17
		From Renee: My 4th grade daughter and I need to find a simple math sentence using 5, 5, 3, & 7 to equal 24. You can add, subtract, divide or multiple. Answered by Penny Nom.
	A sale on eggs		2002-01-17
		From A student: A store had a sale on eggs, selling 13 eggs for the usual price of a dozen eggs. As a result, the price of the eggs was reduced by 4 cents a dozen. What is the original price for a dozen eggs? Answered by Penny Nom.
	My salary is doubled everyday for 30 days		2002-01-17
		From Kanishk: I recieve 1 penny the 1st day, 2 pennies the 2nd day, and my salary is doubled everyday for 30 days. How much money will I have by the end of the 30 day time period? (Is there a way of solving this problem without a chart?) Answered by Penny Nom.
	A sequence		2002-01-16
		From Chris: I have spent two days trying to determine the pattern to the following set of numbers: 1,4,9,1,6,2,5,3,6,4,9,6,4,8,1,____. I need the next four numbers to the sequence. Answered by Claude Tardif.
	Children and probability		2002-01-16
		From Bill: If a family has four children, what is the probability that all 4 are the same sex? Answered by Vanrei Volodin.
	Negative exponents		2002-01-16
		From Julie: If z to the power of -4= 1/z4 then how would you solve 1/t-2? Answered by Penny Nom.
	Linear regression		2002-01-16
		From Murray: If you have a set of coordinates (x[1],y[1]),(x[2],y[2]),...,(x[n],y[n]),find the value of m and b for which SIGMA[from 1 to m=n]AbsoluteValue(y[m]-m*x[m]-b) is at its absolute minimum. Answered by Harley Weston.
	50%		2002-01-15
		From Lakarrieh: 4 is 50% of what number? Answered by Penny Nom.
	What is a group of three numbers called in a large number?		2002-01-15
		From Laurie: What is a group of three numbers called in a large number? My son has this question on his 4th grade worksheet. I've taught middle school math for 7 years and nver heard of it. Answered by Paul Betts.
	8% tax		2002-01-15
		From A student: total price including tax is $13359.60 8% tax was paid What is the dollar amount of tax paid? Answered by Penny Nom.
	Algebra review questions		2002-01-14
		From A student: A wildebeast was observed racing a distance of 86.4m in 4.8 seconds. Find the speed of the wildebeast in m/s. 8x - 7 - 5x = 23 7 z - 3 (z + 2) = 26 Answered by Penny Nom.
	Adding vectors		2002-01-12
		From Lena: how do you add vectors together? If you are given the length and angles of both vectors and are asked to add/subtract them, how do you do it? I know you are supposed to do the head to tail method, but whenever i try it i get the wrong answer. I need help setting it up. example: A is 2.7cm, and 60 degrees, B is 1.6cm and 135 degrees, find the magnitude and amplitude Answered by Penny Nom.
	The tangent function		2002-01-12
		From Justine: if you know that sin45degress = cos45degrees, how do you know that tan45degrees = 1? Answered by Penny Nom.
	The famous "train problem"		2002-01-12
		From Karen: How do you solve the famous "train problem"? For example, 2 trains leave different stations at the same time. One is traveling at 50 mph and the other at 40 mph. How long does it take them to meet? Answered by Penny Nom.
	Papy's Computer		2002-01-11
		From Mary-Anne: My second-grade son brought home a fun math worksheet which involved calculating sums using "Papy's Computer." I had never heard of this before and found it to be quite interesting. Each digit in a decimal number is represented by a 2x2 grid. Each grid square corresponds to one of the numbers 1,2,4, or 8. Answered by Harley Weston.
	Why do integers have the symbol of Z?		2002-01-11
		From Stephanie: Why do integers have the symbol of Z? Natural numbers have the symbol of N, whole numbers have the symbol of W. Our professor has asked us to find out why the letter Z is represented for integers. Answered by Penny Nom.
	A sequence of number pairs		2002-01-10
		From Terry: Three is the first number of a pair, and 8 is the second. a. If 50 is the first number, what is the second number? b. If 200 is the first number, what is the second number? c. If 89 is the second number, what is the first number? d. If a number n is the first number, what is the second number? 3-8 4-11 5-14 6-17 ____ ____ ____ 10-29 ____ ____ ____ Answered by Peny Nom.
	Glasses of wine		2002-01-10
		From A student: 6 glasses of regular wine (12% alcohol) would equal aprox.? glasses of wine (8% alcohol) a)9.33 b)8.5 c)7.75 d)9.0 Answered by Peny Nom.
	A simplification problem		2002-01-10
		From A Parent: FIND (A / B) . (C / D) where A = Y squared + 3 . Y cubed B = Y squared + 4 C = 2 . Y + Y squared D = Y + 4 Y squared + 3 Y cubed Answered by Penny Nom.
	An octagon inscribed in a circle		2002-01-10
		From Kent: A circle of 30 in. diameter has an octagon (8 equal chords) inscribed in it. What is the length of each chord? Answered by Chris Fisher.
	Nickles, dimes, quarters and fifty cent pieces		2002-01-08
		From A parent: The total for all coins counted is $4,564.50 The last coin added to the pile is a 50 cent piece There are 8 times as many 50 cent pieces as there are quarters There are 6 times as many dimes as nickles How many of each are there? Answered by Penny Nom.
	All of the Christmas trees are fifty-five percent off.		2002-01-08
		From A teacher: All of the Christmas trees are fifty-five percent off. Madison bought a tree and paid $103.50. Assuming no tax, what was the original price of the tree? Answered by Penny Nom.
	Maple trees and pine trees		2002-01-06
		From A student: A team of scientists found that in a forest there was four maple trees for every nine pine trees.How many maple were there if they counted 45 more pine than maples? Answered by Penny Nom.
	Catenary		2002-01-02
		From Jason: I am a high school math teacher. I was asked by a friend who is in architectural design for a method for determining the volume of what he called a Catenary. The Catenary curve is modeled by the equation y=a cosh(x/a). I ran into a mess when I tried to compute the volume of the solid formed by revolving that curve around the y-axis. Any help you can provide would be greatly appreciated. Answered by Harley Weston.
	Isoperimetric quotients		2002-01-02
		From A student: I'm stuck on my GCSE Maths coursework, what do isoperimetric quotients measure? Answered by Penny Nom.
	2/3 vs 3/4		2002-01-02
		From Julia: So, here's my question. Some of the problems they've had to do starts off with two fractions, and they have to tell whether the two fractions are: The first one is greater than the second one The first one is less than the second one, or They are equal. One day my son had the problem of 2/3 vs 3/4. Without drawing out a pie chart, how in the world can a child "eyeball" a problem like this and tell what the correct answer is? I've also tried to teach about making common denominators, but that's going over his head at this point. Answered by Denis Hanson and Harley Weston.
	Fractions to decimals and percents		2001-12-31
		From A student: 2/5 , 4/8 , 4/10 , 3/5 , 6/8 , 7/7 (what is the decimal and percent for each) 1/5 , 1/10 , 1/8 , 1/1 (what is the decimal for each) 100 PERCENT, WHAT IS THE DECIMAL? The ratio of boys to girls in a class is 1:4. What percent of the class are girls? Answered by Penny Nom.
	A hyperbola centered at (0,0)		2001-12-28
		From Carla: Find the equation of the hyperbola centered at (0,0) with vertices at (0,3) and (0,-3) that is asymptotic to the lines y=+-5x. Find the equation of a hyperbola in standard position foci (1,5) and (1,7) and eccentricity 2. Answered by Peny Nom.
	Two algebra problems		2001-12-24
		From Cass: if the graph of a equation is 2x2 - y2 = 8 passes through point (6,k), find the positive value of k. if 5x2 - 2 x = 1, find positive value of x Answered by Penny Nom.
	The probability that the area of a triangle is smaller that 1/8		2001-12-21
		From Hoda: Given unit square pick two points on adjacent sides of the square , what is the probability that the area of the resulting triangle is smaller that 1/8? I tried to tackle the problem by first sketching a square with the four vertices at (0,0), (1,1), (0,1) and (1,1). The answer seems to be the area under the curve y=0.25/x between 1 and 0, but how can you integrate such a function when ln0 is undefined? any help would be highly appreciated. Answered by Andrei Volodin.
	Feeding Jumbo		2001-12-21
		From Lupe: There are 2 dogs one named major and the other jumbo. major weighs 100 pounds and jumbo 150 pounds. they eat dry dog food which comes in a 40-pound bag that cost $30. Together, major and jumbo eat a whole bag a week. major eats two fifths of the bag while jumbo eats the rest.How much would it cost to feed jumbo in february, which has 28 days? Answered by Penny Nom.
	450 students		2001-12-19
		From Jessie: My teacher told me that the number of ways of lining up the 450 students in our school is larger than the number of atoms in the universe. Is this right? This question came to Good Question, a regular feature on the CBC Morning Edition radio show in Saskatchewan. Answered by Denis Hanson and Harley Weston.
	Getting to B in the shortest time		2001-12-19
		From Nancy: A motorist in a desert 5 mi. from point A, which is the nearest point on a long, straight road, wishes to get to point B on the road. If the car can travel 15 mi/hr on the desert and 39 mi/hr on the road to get to B, in the shortest possible time if...... A.) B is 5 mi. from A B.) B is 10 mi. from A C.) B is 1 mi. from A Answered by Penny Nom.
	Simultaneous equations		2001-12-17
		From Matthew: 4x + y = 4 2x - 3y = 5 what is x and y Answered by Penny Nom.
	Making toys		2001-12-17
		From Karen: Jonathan and Morgan are two of Santa's elves. Jonathan can make a toy in eleven hours. Morgan can make the same toy in nine hours. How long it take for both Jonathan and Morgan to make the toy if they were working together? Answered by Claude Tardif.
	Composition of functions		2001-12-16
		From Paula: if f(x)= 3x-1 and g(x)= 1/2x + 3 find fog(2) find the values of x for which tanx=0 Answered by Penny Nom.
	A 1 m by 1 m square box in the xy-plane		2001-12-15
		From Murray: Inside a 1 m by 1 m square box in the xy-plane, there are finitely many line segments, whose lengths sum to exactly 10 m. Show that there exists a straight line in the plane which crosses at least six of these line segments. (Hint: first, show that there exists a straight line in the plane which crosses at least five of these line segments.) Answered by Claude Tardif.
	A right-angled triangle		2001-12-13
		From Pamela, Jeff, Kayleigh and Jacob: A right-angled triangle has one side that is 8 cm shorter that the hypotenuse. The other side is 1 cm shorter than the hypotenuse. Find the length of the sides. Answered by Penny nom.
	Algabra		2001-12-13
		From Stephanie: My name is Stephanie. My grade 7 class is doing some strange form of algebra which I've never done nor seen before. We are doing equations like these: 3y - 6 + 7 - 4y = 6y - 6. I don't really understand them and was wondering if you could help me do my homework and explain how to at the same time. It would be really great if you could!!!!! Thank you so much! -Stephanie -9x - 5 - 8 + x = ? 5 + 6x - 3y + x + 8y = ? -x - 3 + 5x + 6y + 8x - 9= ? Answered by Penny Nom.
	Reduce 79,537/3,623,420		2001-12-13
		From Eliana: How do you reduce 79,537/3,623,420. Answered by Claude Tardif.
	A 7% increase		2001-12-12
		From Lorraine: how do you calculate an old salary if the only information you have is current salary and the percentage increase received. For example if I make $15.86 an hour and I received a 7% increase, how much did I used to make? Answered by Penny Nom.
	For 7 the multiplicand is 143		2001-12-12
		From Cory: For 7 the multiplicand is 143 I am asked to solve this, if you could help me it would be greatly appreciated! Answered by Penny Nom.
	A quadrilateral with 0 sets of parallel sides		2001-12-12
		From Jess: Ok well for quadrilaterals a parallelogram is a 4 sided figure with 2 sets of parallel sides and a trapezoid is a 4 sided figure with 1 set of parallel sides. So is there a name for a quadrilateral with 0 sets of parallel side? Answered by Chris Fisher.
	Painting walls		2001-12-12
		From Rizwan: 3 sixth graders painted 4 walls in 3.5hrs. At that rate, how many walls would they paint in 7 hrs. Answered by Penny Nom.
	Recalling the basic facts		2001-12-12
		From A parent: My son is in 4th grade and is a very bright student. He is in the gifted program and makes straight A's on his report card and has through out school so far. My question is how can I teach him to memorize his basic math facts? He does well in math, but when he is placed in a times situation for completing math fact sheets he freezes up. He can not recall the basic facts when questioned at any other time either. He will calculate the answer in his head, like 6 + 3, but he can't just come out with the answer quickly. How can I help him? Answered by Claude Tardif.
	Division symbol		2001-12-12
		From Amanda: What is the name of the symbole used in a long divison problem that seperates the two factors? It looks like a little house. Answered by Penny Nom.
	Exponential form		2001-12-11
		From Crystal: Hi, I am asking a question on behalf of a homeschooling grade 11 student. She is having trouble with changing something like (3-4)2 into a exponential form. First of all she needs to know what the term means "exponential form" and then the process of it. Answered by Penny Nom.
	y = zx - x - c		2001-12-11
		From Andrew: Could you please help me work out the value of x where: y = zx - x - c Answered by Penny Nom.
	Normal lines		2001-12-11
		From Kristie: Why are perpendicular lines called normal lines? Answered by Chris Fisher.
	Cinderella clothes		2001-12-11
		From A student: If cinderella clothes, inc. has determined that 0.5% of all incoming phone calls involve complaints, what is the probability that in 200 incoming calls there are more than one complaint? Answered by Andrei Volodin.
	y= (3x+2)/(4x-5)		2001-12-05
		From Courtney: y= (3x+2)/(4x-5) solve for x Answered by Penny Nom.
	Piles of coins		2001-12-05
		From A student: Sharon has less than 20 coins. When she puts them in piles of 5, she has 1 left over. When she put them in piles of 3, she also has 1 left over. How many coins does Sharon have? Answered by Penny Nom.
	QED		2001-12-05
		From Derek: What does Q.E.D. mean? Answered by Harley Weston.
	Fractions in lowest terms		2001-12-05
		From Thomas: how to change decimal to a fraction in the lowest terms .7 .65 .019 .0111 .225 .1225 .625 .25 .025 .26 .875 .5 .75 .750 .33 .09 .44 .15 .12 .90 .044 .2500 .95 .500 .02 .40 .125 .1276 .00009 .45 .125 .1276 .375 .975 .054 .0005 .20 .2 .0001 .85 .80 .9 .0007 9.8 10.17 25.75 48.4 80.35 19.64 276.20 31.042 18.1034 Answered by Penny Nom.
	Two equations in two unknowns		2001-12-04
		From Courtney: y = 3x + 2 y = 4x - 5 solve for x Answered by Penny Nom.
	Permutations and combinations		2001-12-03
		From Linda: There are 12 people who can be chosen for a project. Q1. Suppose that 2 people refuse to work together. How many groups of 7 can be chosen to work on a project? Q2. Suppose that 2 people insist on working together or neither will work on the project. How many groups of 7 can be chosen to work on the project? Answered by Penny Nom.
	83.3%		2001-12-03
		From Ellie: Please explain how a percentage like 83.3% is changed into a fractions. The answer given is 5/6 and I changed 83.3% to a regular decimal of .833, which would be 833/1000. How do they get 5/6 from that? HELP Answered by Chris Fisher.
	Integers		2001-12-02
		From Alison: How do you use integers in your everday life? Answered by Harley Weston.
	Solving x^2-3x+5=0		2001-11-30
		From Katy: How do you find the solution to x2-3x+5=0? Answered by Penny Nom.
	Can a infinite set be smaller than another infinite set?		2001-11-29
		From Carlos: Can a infinite set be smaller than another infinite set? If so why? Answered by Chris Fisher and Penny Nom.
	3, 6, 10, 15, 21		2001-11-29
		From Patrick: we are trying to find the expression to solve for the nth term in the pattern 3, 6, 10, 15, 21 Answered by Denis Hanson.
	A lighthouse and related rates		2001-11-29
		From Melissa: A lighthouse is located on a small island 3 km away from the nearest point P on a straight shoreline, and its light makes 4 revolutions per minute. How fast is the beam of light moving along the shoreline when it is 1 km from P? Answered by Penny Nom.
	Multinomial theorem		2001-11-28
		From Murray: Could you please state and explain the multinomial theorem (I already know the binomial theorem etc, to give you an idea of where i am) Answered by Harley Weston.
	Slope intercept form		2001-11-27
		From A student: what is slope intercept form? Answered by Penny Nom.
	Numerical problems		2001-11-27
		From Yossi: I am preparing a 45 minutes class for K-12 students. The problem is to show that algebraic equivalent expressions are not always numerically equivalent. In particular I would like to show one of these dangers: cancellation that occurs during the subtraction of nearly equal quantities. Do you have a good reference I could use to prepare my class. In particular to be able to show some examples and how one can avoid this type of error. I also would like to show examples with practical use. I tried to look up in the web but did not find anyhting appropriate. Answered by Chris Fisher.
	Original value		2001-11-27
		From Lisa: We are trying to find the original value of a product marked up by 10%. What is the formula to determine the original value? Answered by Penny Nom.
	Dual spaces		2001-11-26
		From Hoda: In the book "Linear Functional Analysis" from Epstein there is a proof (page 116) of the following theorem: The dual space of Lp is equal to Lq. Later, it is stated as a theorem without proof that for 1 <= p < +infinite, The dual space of lp is equal to lq. Answered by Doug Farenick.
	Ratios and proportions		2001-11-26
		From Adam: I am doing a project where I come to this website and ask a math expert about a certain topic. My topic is ratios and proportions. Can you please tell me what your job is and how you use ratio's and proportions in your job. Can you also please explain what ratios and proportions are. Answered by Harley Weston.
	A health club		2001-11-25
		From Maria: A health club with a membership of 650 people operates a running track and an indoor swimming pool. A survey of the membership indicates that 68% use the running track, 44% use the swimming pool, and 8% use neither. If a member is chosen at random, what is the prbability that the member uses: a) Both the track and the pool? b) Only the track? Answered by Penny Nom.
	L'Hopital's Rule		2001-11-25
		From Mike: I'm a high school senior. I'm in ap calculus and was wondering if you know the proof of L'Hopital's Rule? Our teacher said he has never been able to find it in a math book and was unable to derive it himself. Answered by Claude Tardif.
	Undetermined coefficients		2001-11-22
		From Hoda: The equation is: y" - 2y' + y = t et + 4 We need to use The method of Undetermined coefficients. I have tried assuming that the solution is Atet+Bet+C, but all I get is C=4 and I tried (At2+Bt+C)et+D, but again I get 0=0 when I calculate the first and second derivatives, so i get no information on the constants. Any suggestions? Answered by Harley Weston.
	Ratios		2001-11-21
		From Mike: Simplify these ratios. 7 1/4 inches to 2 feet. $0.02 per $1.75 Answered by Peny Nom.
	Matrix		2001-11-21
		From Hoda: I have a question about matrix multiplication; well, actually, matrix division. I am assuming that matrices are divided the same as they are multiplied; that is, row by column. But what happens if you have to divide by zero? How does this affect the resulting matrix? Answered by Patrick Maidorn and Penny Nom.
	A tangent line		2001-11-21
		From A student: write an equation of the line tangent to the graph of ey + ln(xy) = 1 + e at (e,1) Answered by Harley Weston.
	A hypercube		2001-11-20
		From Ace: Can I get a picture of a hypercube Answered by Patrick Maidorn.
	Rewriting and evaluating formulas		2001-11-19
		From A conserned mother: Due to the wide range of temperatures experienced in Canada, engineers who construct roads must allow for expansion and contraction of the road surface. The following formula is used to calculate the amount of expansion E to allow for: E= kL(T-t), where k is the constant of expansion for the road surface. L is the length of the section of highway in metres. T is the temperature of the air in degrees Celsius. t is the temperature, in degress Celsius, at which the section of the highway was constructed. Answered by Walter Whiteley.
	Cardinality of sets		2001-11-19
		From Tania: Show that the cardinality of P(X) (the power set of X) is equal to the cardinality of the set of all functions from X into {0,1}. Show that (the cardinality of the natural numbers set) |N| = |NxNxN|. Show that the cardinality of the set of prime numbers is the same as the cardinality of N+ Answered by Walter Whiteley.
	Gallons		2001-11-19
		From Shawn: Do we use British or American gallons in Canada? Answered by Chris Fisher.
	Translated by the vector (-5,2)		2001-11-19
		From Jennifer: Give the image of (p,q) when translated by the vector (-5,2). Answered by Penny Nom.
	The "pi" of a circle in hyperbolic space		2001-11-19
		From Alex: How can you find the "pi" of a circle in hyperbolic space (or is it the same). I would like to know because our environment is hyperbolic and if the "pi" of hyperbolic space is irrational, it would follow that space is non discrete. I would greatly appreciate any help in this question. Answered by Walter Whiteley.
	Box and Whisker plots		2001-11-19
		From Rod: In our Prealgebra course, we have been studying Box and Whisker plots. Recently, we learned how to decide whether a data point is an outlier or not. The book (Math Thematics, McDougall Littell) gave a process by which we find the interquartile range, then multiply by 1.5. We add this number to the upper quartile, and any points above this are considered to be outliers. We also subtract the number from the lower quartile for the same effect. My question: where does this 1.5 originate? Is this the standard for locating outliers, or can we choose any number (that seems reasonable, like 2 or 1.8 for example) to multiply with the Interquartile range? If it is a standard, were outliers simply defined via this process, or did statisticians use empirical evidence to suggest that 1.5 is somehow optimal for deciding whether data points are valid or not? Answered by Penny Nom.
	Renee, Paulo and Peter		2001-11-18
		From Sue: Renee is 5 years older than Paulo. she is also 7 years older than Peter. The sum of their ages is 21. How old is each person. Answered by Penny Nom.
	Number sequences		2001-11-17
		From Stephanie: My name is Stephanie. My grade 7 math class is studying number sequences and, to me, they make almost no sense at all. Here I wrote down 2 of the many problems I have for homework and was wondering if you could explain them to me (I have to find the next 3 numbers in each sequence.) It would be a big help! 10, 14, 18, 22, _, _, _. 12, 21, 39, 75, _, _, _. Answered by Penny Nom.
	A box of pants and shirts		2001-11-17
		From Debbie: I need to determine the volume of a box that is 4'HX4'WX4'L. The box contains uniform pants and uniform shirts. I need to know how many shirts and pants are in the box. When folded, the uniform shirt is .5 inches thick. The pants are also .5 inches thick. Answered by Penny Nom.
	How do you get to 100 by using 6 nines?		2001-11-17
		From A student: How do you get to 100 by using 6 nines? Answered by Claude Tardif.
	Magic squares		2001-11-17
		From A student: 7th grader wanting to find solution to magic square: place the integers from -5 to +10 in the magic square so that the total of each row, column, and diagonal is 10. The magic square is 4 squares x 4 squares. Answered by Penny Nom.
	Some functions without numbers		2001-11-16
		From A student: I have a worksheet that is about functions. It doesn't only use numbers. I need help to figure out the function and the solution to how the answer is solved. Answered by Claude Tardif.
	Numbering pages		2001-11-15
		From Lucy: A printer uses 1008 digits to number the pages of a book. How many pages are there in the book? Answered by Penny Nom.
	Negative numbers		2001-11-15
		From Jewel: If zero means nothing or an empty set, then how can a number be less than zero, as in negative number? My understanding of negative numbers is distance from a set point in a given direction. Thus having a negative and positive side of a line is arbritary and is related to displacement rather than value. Am I in error? Answered by Penny Nom.
	A clap of thunder		2001-11-15
		From Frustrated Mom: While getting a recipe for the Thanksgiving feast. The teacher was talking on the phone with a friend who lives four miles north of her. She saw a flash of lightning through the window: fifteen seconds later, she heard a clap of thunder. Ten seconds after that she heard the thunder over the phone. Where did the lightning strike in relation to the teacher's house. (There are two possible answers. Sound travels about 1/5 mile per second. Some people say it's not good to be on the phone in a thunderstorm). Answered by Claude Tardif and Penny Nom.
	what number doubled plus 20 will give you 4/3 the original number		2001-11-15
		From Hank: what number doubled plus 20 will give you 4/3 the original number 2 x__ + 20 = 4/3 of the original number Answered by Penny Nom.
	(a+b) squared and a squared plus b squared		2001-11-14
		From Kristen: (a+b)2 = a2 + b2 Is this true for all whole numbers, and why? Answered by Penny Nom.
	Subsets of a countably infinite set		2001-11-14
		From Tania: How could I show (and explain to my son) that any countably infinite set has uncontably many infinite subsets of which any two have only a finite number of elements in common? Answered by Claude Tardif.
	3x-1/2(x-4)+5= -3		2001-11-13
		From Tausa: 3x-1/2(x-4)+5= -3 Answered by Penny Nom.
	Inequalities		2001-11-13
		From Pat: When writing the solution to an inequality, why is the solution written in set notation? {x/ } Answered by Penny Nom.
	Prove that the medians of triangle PQR meet in a central point G.		2001-11-11
		From Jessica: Use a scalene triancle with one point (0,b) on the y axis, another point (2c, 0) on the x-axis and the last point, (2a,0) on the x-axis. Prove that the medians of triangle PQR meet in a central point G. Answered by Penny Nom.
	A cubic		2001-11-10
		From Louise: x3 + 9x2 - 7x - 63 Answered by Penny Nom.
	1 minus 5(y) equals negative 2		2001-11-10
		From Judy: 1 minus 5(y) equals negative 2 Answered by Penny Nom.
	A circle and triangle overlap		2001-11-09
		From Tara: A circle and triangle overlap as shown.the area of the circle is three times the area of the triangle.If the common region is removed,then the area of the rest of the circle would be 14 sq cm more than the area of the rest of the triangle.How many sq cm are in the area of the complete triangle. Answered by Penny Nom.
	A circle and a triangle		2001-11-09
		From Tasha: I have a circle that has an equalateral triangle inscribed in it. The tip of the triangle (B) is at the center of the circle with the other corners (A & C) extending to the sides of the circle. I need to know the equation to find the linear length of AC. I also need to find the cordial length of the circle from point C to A. Answered by Penny Nom.
	Third side of Acute Triangle		2001-11-09
		From Don: I gave this problem to my children, 9th and 12th grade and they are not(me too!) sure of the answer. I am trying to determine the length of the third side of an acute triangle. I know two of the lengths but I do not know the angles. Is there a proper formula to use to find the length of the third side? Thank you. Answered by Chris Fisher and Penny Nom.
	12 pairs playing bridge		2001-11-09
		From Diana: I have 12 pairs playing bridge against one another for 12 games. I need to have each pair partnered with another pair -- but only once. I'm looking for a schedule for play for all 12 games. They should only be able to play against another team only once also. (ex: 1/2 v 3/4 then 4/2 v 3/1) Thank you for this opportunity to solve my dilemma. Answered by Claude Tardif.
	Asymptotes		2001-11-09
		From Frank: given the function: f(x) = (x2) / (x-1) the correct answer to the limit of f(x) as x approaches infinity is: y = x+1 all math references point to this answer and the method they all use is long division of x-1 into x2 however if one were to multiply both the numerator and denominator by 1/x and then take the limit, one gets: y=x how can the descrepency between the two answers be explained? Answered by Chris Fisher and Penny Nom.
	A 3 dimensional 5 pointed star		2001-11-08
		From Kent: I am looking for a formula that will give me a layout for a 3 dimensional 5 pointed star. I want to form it out of sheet metal, using 5 polygons and soldering them at the apex. Can you please help me with this? I would like to be able to give the formula the height of the star from the bottom two points to the top point and also how deep the star is. Thank you very much! Answered by Judi McDonald.
	Manufactures golf balls		2001-11-06
		From Kevin: A company manufactures golf balls. Golf balls are each numbered consecutively 0 to 4, and then the numbering starts over with zero again. Every 12th golf ball is yellow. Every 8th golf ball is tested for defects. The company produces 120,000 golf balls in an eight-hour shift. A. How many yellow golf balls are tested for defects during the day? Explain your reasoning. B. How many of these yellow balls that are tested are imprinted with the numeral 2? Explain your reasoning. Answered by Penny Nom.
	Counting CD's		2001-11-06
		From Jason: An older brother said to his younger brother, "Give me 8 of your CDs, then I will have twice as many as you." The younger brother replied, "No, you give me 8 of yours instead, and then we'll have an equal number." How many CDs does each boy have? Answered by Chris Fisher.
	2=the square root of (2 + the square root of (2 + the square root of (2 +...)))		2001-11-05
		From Cynthia: justify algebreically, that: 2=the square root of 2 + the square root of 2 + the square root of 2 + the square root of 2 + the square root of 2 + and so on, ....... Answered by Penny Nom.
	Squares of negative numbers		2001-11-03
		From Susana: I wanted to know if I can square a negative number..? Answered by Leeanne Boehm.
	Applied geometry		2001-11-02
		From Jenny: Where can I find some hands-on activities for my Applied Geometry classes? I want to do more activities with them that allow us to get out of the classroom. However, I want to use activities that use only inexpensive equipment because I usually buy the equipment myself. Answered by Walter Whiteley.
	A lighthouse problem		2001-11-02
		From A student: A lighthouse at apoint P is 3 miles offshore from the nearest point O of a straight beach. A store is located 5 miles down the beach from O. The lighthouse keeper can row at 4 mph and walk at 3.25 mph. a)How far doen the beach from O should the lighthouse keeper land in order to minimize the time from the lighthouse to the store? b)What is the minimum rowing speed the makes it faster to row all the way? Answered by Harley Weston.
	15 % of 24.95		2001-11-01
		From Puzzled: How do I take 15% of a number I have forgotten Answered by Penny Nom.
	8w-15 = 3w-10		2001-11-01
		From A student: 8w-15=3w-10, w =????? Answered by Paul Betts.
	Division by zero		2001-10-31
		From Stacy: I have a question about dividing with zero. When the numerator is zero, the answer is zero. But when the denominator is zero, the answer is undefined. Why? I don't understand Answered by Claude Tardif.
	(-3)to the power 2, divided by 3		2001-10-31
		From Raz: what is (-3)to the power 2, divided by 3= Answered by Penny Nom.
	m - 8		2001-10-30
		From Danita: Can you please e-mail me the answer to m -8 for m = 20 and how you got the answer Answered by Penny Nom.
	3pi/2 - pi		2001-10-29
		From Karen: I need to simplify this a) 3pi/2 - pi Answered by Penny Nom.
	A sample size problem		2001-10-28
		From Charles: The U.S Transportation Dept. will randomly sample traffic reports to estimate the proportion of accidents involving people over the age of 70. The Dept. has no advance estimate of this proportion. how many reports should the dept select to be atleast 97% confident that the estimate is within .01 of the true proportion? Answered by Harley Weston.
	Three problems		2001-10-28
		From Brenda: Joseph is planting bushes around the perimeter of his lawn. If the bushes must be planted 4 feet apart and Joseph's lawn is 64 feet wide and 124 feet long, how many bushes will Joseph need to purchase? The cost of a long distance phone call is $1.50 for the first two minutes and $0.60 for each additional minute. How much will Maria pay for a 24 minute phone call? Find the next three numbers in the pattern. 1,3,7,15,31,___,____,___. Answered by Penny Nom.
	Is the tree a pine tree?		2001-10-27
		From Kate: Suppose Stock Brokers tell the truth 2/5 of the time, and 1/3 of the trees in a given forest are Pine. If 4 Stock Brokers say that a certain tree in that forest is Pine, what is the probability that the tree is indeed a Pine tree? Answered by Penny Nom.
	Negative times negative is positive		2001-10-26
		From Mary: I have a question about adding and multiplying positive and negative numbers. When we add two negative numbers the answer is negative BUT when we multiply two negative numbers the answer is positive. I don't understand. Why? Answered by Penny Nom.
	Why do you flip the inequality sign?		2001-10-26
		From Sean: I have a question about an inequality problem. Here it is: Solve and graph 5 - 3x => 17. (=> is greater than or equal). Please tell me why you flip the inequality sign when divinding by a negative number. Answered by Penny Nom.
	Concavity of f(g)		2001-10-25
		From Troy: Suppose f & g are both concave upward on (-infinity,infinity). Under what condition on f will the composite function h(x)= f(g(x)) be concave upward? Answered by Walter Whiteley.
	An algebraic fraction		2001-10-25
		From brandi: 4x - 5 _____ =4 3-7x Answered by Penny Nom.
	Metric units		2001-10-25
		From Kelly: i am helping my kids out with school work and don't remember meters,centimeters decimeters and all those. We have to change meters into cm.....and so on..........is there a place on the web to look for some kind of help in these questions Answered by Penny Nom.
	Where is the fourth point?		2001-10-24
		From Mike: Four points are placed at random on a piece of paper. Connect the three points of the triangle of the largest area. What is the possibility that the fourth point is in the triangle? Answered by Penny Nom.
	A geometric series		2001-10-24
		From Tashalee: The sum of the first 3 terms of a geometric series is 13. The sum of their reciprocal is 13/9. how do you find the first three terms? Answered by Penny Nom.
	Free pamphlets		2001-10-24
		From Salman: a travel agency has limited number of six different free pamphlets about the beetle islands. the agent tells you to take any that you want, but not more than two of any kind. Assuming that you take at least one pamphlet, how many choices could you make Answered by Penny Nom.
	A right angled triangle		2001-10-23
		From Carissa: How do you : Triangle ABC is right-angled at A. Calculate the length of the third side if b = 3 and c = 6, express the answer as a surd in its simplest form. Answered by Harley Weston.
	The distributive law		2001-10-23
		From Carissa: How do you simplify the following using the distributive law : 5 squareroot 2+3 squareroot 2? Answered by Penny Nom.
	A $10,00 prize		2001-10-23
		From Michelle: The grand prize for winning a contest is $10,000. After 28 percent of the prize is deducted for taxes, the winner receives the balance of the prize in annual payouts of equal amounts over a 3-year period. How many dollars will the prizewinner receive each year of the 3 years?(Disregard the $ sign when gridding your answer.) Answered by Penny Nom.
	Squaring the circle		2001-10-23
		From Margaret: I have the following question that I cannot answer on my own (I don't know where to begin): Is it possible construct a square whose area will equal the area of a given circle? Please Explain why or why not. Answered by Penny Nom.
	The average of two polygons		2001-10-23
		From Irene: How can I prove that the average of two polygons will give me another one? Answered by Walter Whiteley.
	Multiplying vectors		2001-10-22
		From Murray: Could you please explain why a vector times a vector is a scalar and how to derive the formula vector a * vector b = ab cos(a,b) Answered by Harley Weston.
	Lines in the plane		2001-10-21
		From Greg: *If the line with equation 3x-4ky= -16 has y-intercept -2, find k. *Write the equation of the line passing through (2,5) and perpendicular to the line passing through (2,-4) and (6,1) Answered by Penny Nom.
	Water in a conical tank		2001-10-20
		From Sarah: The problem: Water flows into a conical funnel at a continuous rate of one gallon per minute (One gallon = 231 Cu.In.). The height of the funnel is 5" and the diameter is 8". The 1st formula: I need to develop a formula that will give the volume, in cubic inches, of the water in the funnel at any time t (in seconds). V = f(t). The 2nd formula: I need to develop a formula that will give the height of the water in the funnel at any time t (in seconds). h = f(t). Answered by Penny Nom.
	Why quadratic for a second degree equation?		2001-10-20
		From Jana: Why do we use the word quadratic to describe second degree equations? Answered by Penny Nom.
	A goat in a square pen		2001-10-19
		From Brad: A goat is tied to one corner of a square pen 20 ft. on a side. If the goat's tether is 10 ft. long, what percentage of the grass in the pen can the goat reach? What should the length of the tether be so that the goat can reach half of the grass? Answered by Penny Nom.
	Symmetry of f(x) = ax^n		2001-10-18
		From Mohammed: a function of the form f(x)=axn, where a doesn't equal 0 and n is a positive integer is called a power function . how is the exponent in the equation of a power function related to the symmetry of its graph? Answered by Penny Nom.
	414 is what percent of 5,624?		2001-10-18
		From A student: 414 is what percent of 5,624? Answered by Penny Nom.
	A function or not a function?		2001-10-18
		From Christian: Which are the following are not functions? y = x2 y = x3 x = y2 y = 3 Answered by Leeanne Boehm.
	Tenths, hundredths, and thousandths		2001-10-17
		From Cheri: I would like the French terms for the decimal place values of tenths, hundredths, and thousandths. (I would be interested in the Spanish terms also if you had them.) Answered by Maria Torres and Claude Tardif.
	Column doesn't add up to 100%		2001-10-17
		From A student: why don't some tables I'm studying in a column add up to 100%? Example: N=338, but responses to questions asked in survey I'm studying equal of 24.3, 9.8, 43.8, DON'T add up to 100%. I'm assuming that some people surveyed out of the 338 didn't bother responding, but is there another problem related to proportion or ratio being used, but improperly labeled on graph?. Note at bottom of table says: "number in parenthesis are numbers of cases" and 338 was in parentheses. I'm lost. Answered by Penny Nom.
	A line in 3 dimensions		2001-10-17
		From Murray: I'm working on a complicated proof and i need the equation for a line in 3 dimensions. Answered by Claude Tardif.
	Dividing a circle		2001-10-17
		From Ahmeen: I am having a hard time figuring out how a circle can be divided into 11 equal parts with only 4 cut allowed? My teacher gave this to us and I still can't cut my pie into eleven equal parts with only four cuts. Answered by Walter Whiteley.
	Dimensions of a frame		2001-10-16
		From Rachel: A rectangular picture frame has a perimiter of 44.2 cm.The width of the frame is seven tenths of its length what are the dimensions of the frame? Answered by Penny Nom.
	Proof by induction		2001-10-16
		From John: Can you help me with any of these? For any natural number n > 1, prove that (4n) / (n + 1) < [(2n)!] / [(n!)2]. For any natural number n > 1, prove that 1/sqrt(1) + 1/sqrt(2) + 1/sqrt(3) + ... + 1/sqrt(n) > sqrt(n). For any natural number n and any x > 0, prove that xn + xn - 2 + xn - 4 + ... + x-n >= n + 1. Answered by Penny Nom.
	Some algebra		2001-10-15
		From James: I cannot figure these out I was wondering if you could help me? I have no one to answer my questions. (7x2 – 3yz)2 – (7x2 + 3yz)2 Use Pascal’s triangle to expand (2x – y)4 8x3 y - x3 y4 (m + 3n)2 – 144 12x4 y – 16x3 y2 – 60x2 y3 p3 q2 – 9p3 + 27q2 – 243 Answered by Peny Nom.
	Squares of one digit numbers		2001-10-15
		From Needa: What two two-digit numbers are each equal to their right-most digit squared? Answered by Penny Nom.
	Rules of exponents		2001-10-14
		From Carissa: how do you work this out? Investigate the relationship between a,b,c and d if 2a*2b=4c/4d? Answered by Leeanne Boehm.
	Absolute Value		2001-10-14
		From Susan: I am a homebound teacher, and my nineth grade algebra I student is having trouble understanding absolute value. Please send me an idea about how to best help her. She may be out of the classroom the entire year. Answered by Chris Fisher.
	Odd plus even is odd		2001-10-14
		From James: Why is the sum of an odd number and an even number always odd? Answered by Peny Nom.
	Area of a quilt		2001-10-14
		From Jack: how would you find the area of the quilt? which is a square how would you fined the area of each square? Answered by Penny Nom.
	Theme day		2001-10-14
		From A teacher: I woulld like a math theme for a theme day in a high school, grades 9-12. Our last theme was fractal fest. Answered by Penny Nom and Claude Tardif.
	Maximize the area		2001-10-13
		From Mike: I have no clue how to do this problem. Here is what the professor gave to us: A=LW C=E(2L+2W) + I(PL) Where P = # of partitions E= cost of exterior of fence I = cost of interior of fence C = total cost of fence . . . Answered by Harley Weston.
	Mathematical & conventional meaning of a word		2001-10-12
		From A student: What is the mathematical & conventional meaning of a word? Like the word Rational or Median. Answered by Penny Nom.
	60 seconds in a minute		2001-10-11
		From Andy: I am a fourth grade teacher. Yesterday my students asked "Why are there 60 seconds in a minute?" Which also led to 60 minutes in an hour? I have had trouble determining why the number 60? Any help would be appreciated. Answered by Penny Nom.
	4 sinx cosy = 1		2001-10-10
		From A student: How would i differentiate the following example in terms of t (x and y are functions of t) 4 sinx cosy = 1 Answered by Claude Tardif.
	Acres		2001-10-10
		From Allison: how many feet are there in an acre? Answered by Chris Fisher.
	eix = cosx + isinx		2001-10-10
		From Peter: Given: eix = cosx + isinx substitute -x for x to find e-ix, simplifying your answer use the given and part a to find an identity for cosx making no reference to trig functions find an identity for sinx . . Answered by Penny Nom.
	When will the ship disappear?		2001-10-10
		From Stacy: If the sail of a ship were a 100 ft. tall and you were a mouse at the edge of the shore looking out at it, how far out would the ship be when it disappears? ( your eye level is level with the water.) Answered by Harley Weston.
	Ratio and proportion		2001-10-10
		From Steve: Where would you use a proportion and/or a ratio in a real life job or problem. Answered by Leeanne Boehm and Walter Whiteley.
	Six nines		2001-10-09
		From A mom: My middle schooler (sixth) has to calculate the integers 0-20 using only 6 nines. We have done all but the integer 14. He can not use decimals or double the nine like 99 or 19. the fraction 9/9 is okay. Keep in mind of course the order of operations. Answered by Claude Tardif.
	Pythagoras & magic squares		2001-10-09
		From John: My grandson became intrigued when he recently 'did' Pythagoras at elementary school. He was particularly interested in the 3-4-5 triangle, and the fact that his teacher told him there was also a 5-12-13 triangle, i.e. both right-angled triangles with whole numbers for all three sides. He noticed that the shortest sides in the two triangles were consecutive odd numbers, 3 & 5, and he asked me if other right angled triangles existed, perhaps 'built' on 7, 9, 11 and so on. I didn't know where to start on this, but, after trying all sorts of ideas, we discovered that the centre number in a 3-order 'magic square' was 5, i.e. (1+9)/2, and that 4 was 'one less'. Since the centre number in a 5-order 'magic square' was 13 and that 12 was 'one less' he reckoned that he should test whether a 7-order square would also generate a right-angled triangle for him. He found that 7-24-25, arrived at by the above process, also worked! He tried a few more at random, and they all worked. He then asked me two questions I can't begin to answer ... Is there a right-angled triangle whose sides are whole numbers for every triangle whose shortest side is a whole odd number? and Is each triangle unique (or, as he put it, can you only have one whole-number-sided right-angled triangle for each triangle whose shortest side is an odd number)? Answered by Chris Fisher.
	Lucas' theorem		2001-10-09
		From Tania: How could I demonstrate: nCp is congruent to floor(n/p) (modulo p)? where rCk is a binomial coefficient, rCk = r(r-1)...(r-k+1)/k(k-1)...1, and p is a prime number Answered by Richard McIntosh.
	Binomial probabilities		2001-10-08
		From Amna: I had a few binomial probability questions which I can not use from the tables as instructed: If 60 % of television viewers are watching a certain program, what is the probability tha tmore than half of those selected in a random sample of five will be watching the specified program? If it is known according to Mendel's Law, that we can expect in teh long run to have 3 white, 1 brown rabbits in every 4 rabbits of a certain type, what is the probability that 2 in a litter of 3 will be white? On the average, 2% of the items sold in a department store are returned for refunds. what is the probability that of its next five items sold, at most two will be returned for refunds? Answered by Leeanne Boehm.
	Mystery mathematician		2001-10-08
		From A student: Theres a mathematician that was born on October 16 1879 in England and died on October 1 1921 in England. Suffered from severe disabilities. Did poorly in his degree and settled for a pass degree. Was awarded the Allen scholarship for research in 1904. He also applied logic to Physics in papers such as On Some Points in the Foundation of Mathematical Physics (1908). Who is it? Answered by Claude Tardif.
	15 mice in 4 cages		2001-10-08
		From Chelsea: How can you fit 15 mice into 4 cages with an odd number of mice in each cage? Answered by Claude Tardif and Harley Weston.
	Finite differences		2001-10-08
		From Murray: My name is Murray and I am a 10th grade student. Me and my friend have recently discovered and proved a theorem of a relitively advanced nature. It is that the the nth difference of an nth degree equation = n! times the coefficient of the highest power. One of my teachers said this theorem is part finite and that she thinks she has seen it before, but she does not remember what it is called, at what level it is taught, who discovered it or when it was invented. I would greatly appretiate answers to any of these questions. Answered by Chris Fisher.
	Locusts		2001-10-08
		From A parent: JOHN CONJECTURED THAT BOTH 13-YR.&17-YR. LOCUSTS CAME OUT THE SAME YEAR. ASSUME IT IS CORRECT. HOW MANY YEARS PASS BETWEEN THE YRS. WHEN BOTH 13 YR. & 17YR. LOCUSTS ARE OUT AT THE SAME TIME? EXPLAIN. NEXT, SUPPOSE THERE WERE 12YR.,14 YR.,& 16YR. LO- CUSTS,& THEY ALL COME OUT THIS YR. HOW MANY YRS. WILL IT BE BEFORE THEY ALL COME OUT TOGETHER AGAIN? Answered by Leeanne Boehm.
	Simplify the expression		2001-10-08
		From Natalia: simplify expression 4(x-7)+(-5x)=-10 Answered by Leeanne Boehm.
	Percentage in our daily lives		2001-10-08
		From Natasha: What are the uses of percentage in our daily lives? Answered by Leeanne Boehm.
	The amount of gravel needed to fill a hole		2001-10-06
		From Rhett: My name is Rhett and my problem is...I am a contractor and I am having problems determining the amount of gravel(in tonnage) needed to fill this hole,the measurements are 60' in length,22' in width,and 14' in height....the problem is that it is not a usual box shaped hole or in this case a rectangle shaped hole,but more of a triangular shaped hole.I refer to the triangular shape as the interior shape of the crater not the exterior,which is shaped like the above dimensions.If you could help it would be greatly appreciated.P.s.This was a retaining wall project,built by myself, in front of a sloped end of a yard,so if you could imagine a 14" high hill with a landslide looking face,then build in your mind a three sided rectangle in front of it using the hill side that slopes as the fourth side of the rectangle,then you may be able to imagine what I mean as a triangular shaped interior of the hole. Answered by Penny Nom.
	Subtracting 5 from 25		2001-10-05
		From Melissa: How many times can you subtract the number 5 from 25? Answered by Leeanne Boehm.
	A circle and a triangle		2001-10-04
		From Christina: The points (3,4), (9.-2), and (-3,-2) define a circle and a triangle. find the areas of the circle and the triangle. Find the difference between their areas. Find the length of a side of a square with the same area as the triangle. Find the length of a side of a Square with the same are as the circle. Answered by Penny Nom.
	A Norman window		2001-10-04
		From Erin: A Norman window has the shape of a rectangle surmounted by a semicircle. If the perimeter of the window is 30 ft, express the atrea, A, as a function of the width x of the window. Answered by Penny Nom.
	Zero as an exponent		2001-10-04
		From Wendy: How do I explain to kids that i.e. 5 exponent 0 = 1? Does 0 exponent 0 = 1? Answered by Leeanne Boehm and Penny Nom.
	Who owns what pet?		2001-10-03
		From A parent: Don, Frank, Jenny, and Ken each come from one state, either Alaska, Maine, Montana, or Oklahoma. They each speak one primary language, either English, french, Russian, or Spanish. And they each have one of four pets, a chinchilla, a dog, a hamster, or a turtle. Figure out which language and what pet each of the four people have, using the following clues. . . . Answered by Judi McDonald.
	A polygon with five sides		2001-10-03
		From A student: I was asked a question in 5th grade today that goes: i am a polygon with five sides and 2 right angles what do i look like and what is my name Answered by Penny Nom.
	The height of the lamppost		2001-10-02
		From Werner: I am working on question 51,section 3.7 ,page 191 of Stewart's Single Variable Calculus. The question involves a lamp post which is casting a shadow around the eliipse whose formula is x2 + 4*y2 = 5. I have found the derivative of the elllipse both explicitly: x/4(((5-x2)/4)0.5) and implicitly : y' = - x/(4*y). Answered by Harley Weston.
	(x^2-5x-6)/(x-6)		2001-10-02
		From Bill: given f(x) = (x2-5x-6)/(x-6) find f'(6). Answered by Harley Weston.
	Building numbers		2001-10-02
		From Dorothy: Using only the numbers 1, 2. 3 & 4 and the order of operations make problems that have the answers of 1 to 50. Use each digit only once per problem. Use +, -, x, (), exponents or use 2 digits to form a 2 digit number Example 1,2=21 or 12. No Division. We have been able to do all the problems except finding the answers of 7, 22, 31, 34, 42, 43 and 50. Answered by Claude Tardif.
	The median of a trapezoid		2001-10-01
		From Laura: Given: A (1,2) B (9,-2) C (7,2) D (3,4) Find the endpoints of the median. Use exact values. Write the equation using the letters from the given trapezoid. Verify the theorem using algebra. Answered by Penny Nom.
	1+2+3+...+1000		2001-10-01
		From Louise: Find a quick way to add all Intergers (whole Numbers) between 1 and 1000? Answered by Walter Whiteley.
	Proof by induction		2001-09-30
		From Kyle: I'm trying to learn induction and I need to see how this done please help with this problem... 20 + 21 + 22 +... + 2n = 2n+1 -1 is true whenever n is a positive integer. Answered by Penny Nom.
	Inverting a function		2001-09-30
		From Brandie: Could you please tell me what is the basic guideline for inverting a function Example: S(R)=2PiRal V(R)=PiR(squared)bl R(V)=? Answered by Claude Tardif.
	The 100 chart		2001-09-28
		From Nich: Am I suppose to use the 100 chart for these questions. Question One: I am a 2 digit number my tens digit is 2 more than my one digit my 1 digit is between 4 & 6. What # am I ? Question Two: I am a 2 digit # I am greater than 40 but less than 60 my tens and ones digits are the same I am a odd number what am I ? Answered by Penny Nom.
	Solitaire		2001-09-27
		From Babahadj: Il s'agit du probleme du solitaire avec des cases numerotees 1, 2 et 3. Un pion se trouve initialement sur chacune des cases, sauf la centrale qui est vide. Au depart, il ya 15 pions sur les cases avec le numero 1 , 15 pions sur des cases avec le numero 2, et 14 pions sur des cases avec le numero 3. Le seul mouvement pour un pion P consiste a manger un pion P' en sautant par dessus ce dernier , a condition que le pion P' soit situe sur une case voisine (horizontalement / verticalement) et que la case dans laquelle aboutit le pion P soit vide. En partant de cet etat initial , est - il possible d'arriver a un etat final avec un seul pion se trouvant sur une case portant le numero 1. Pourquoi? Merci de me repondre. 1 2 3 2 3 1 3 1 2 1 2 3 1 2 3 1 2 3 2 3 1 2 3 1 2 3 1 3 1 2 3 1 2 3 1 2 1 2 3 2 3 1 3 1 2 Answered by Claude Tardif.
	1:5		2001-09-27
		From Sandy: A colleague and I have a disagreement about dilutions. I seem to remember that I was taught (although it was a long time ago) that a RATIO was written thusly: 1:5 , and read " one part to five parts", for a total of 6 parts. On the other hand, a fraction is written: 1/5 and is read" one part in five" for a total of 5 parts. My colleague says that the ratio reads "one part in five" and is essentially the same as a fraction. Which is right? Have I been doing dilutions wrong all this time? I teach Animal Nursing and need to know where I can find a consise answer to such questions for making up medicated fluids, etc. Answered by Penny Nom.
	A bag with 3 red marbles and		2001-09-27
		From Mike: In a bag, there are 3 red marbles and "B" blue marbles. Two marbles are randomly selected from the bag without replacement. The probability that the two marbles are the same color is 0.5. Calculate the sum of all possible values of B. Answered by Claude Tardif.
	The triangle inequality		2001-09-27
		From A student: __ __ __ Prove that AX + XB = AB for any X on AB. Answered by Chris fisher.
	Find the pattern		2001-09-26
		From A parent: MY SON HAD ON A WORKSHEET WHAT I HAVE LISTED BELOW, BUT WE CAN'T SEEM TO FIND THE PATTERN. MOST THE TIME WE CAN, BUT THIS ONE IS DIFFERENT. 6,___, 9,____,____,_____,_____,_____ Answered by Caude Tardif.
	Joan and Jan work together		2001-09-26
		From Karyna: Joan and Jan work together and they set up a bandstand in just 24 minutes, but if Joan does it by herself she takes 1 hour. How long would it take Jan to set up the bandstand by himself? Answered by Claude Tardif.
	Bicycles and tricycles		2001-09-26
		From Sally: A bicycle shop has 5 bicycles and tricycles to repair. They have 12 wheels. What strategy would you use to determine how many bicycles and tricycles need to be repaired? Answered by Claude Tardif, Diane Hanson and Penny Nom.
	Scoring a college placement test		2001-09-26
		From Carmen: A college placement test consist of 75 multiple-choice questions, each having 5 possible answers. The exam is scored by subtracting from the number of correct answers one-quarter of a point for each question answered incorrectly. If a person answers every question on the exam and scored 45, how many questions were answered wrong? Answered by Penny Nom.
	Investing in a yacht		2001-09-26
		From Junior: Marvin and his four friends wish to invest in a yacht by sharing equally in the cost. As the date of sale approaches, Marvin realizes that if three more people join the partnership, each partner's share would decrease by $18,000. How much does the yacht cost? Answered by Penny Nom.
	Julia goes to work		2001-09-25
		From Karyna: On one October morning, Julia rides her bike (at 12 miles per hour) from her home to her friend Ida's house; then the two of them walk (at 6 miles per hour) to work. If it takes an hour for Julia to go the 10 miles from her home to work, how far does she walk? Answered by Penny Nom.
	GCD and LCM		2001-09-24
		From David: Find the GCD adn LCM of the following numbers. Assume p 2 to the power p, 3 to power q, 5 to power r and 2 to power q, 3 to power r, 7 to power p Answered by Penny Nom.
	Four sequences		2001-09-24
		From Nicole: I have a few questions I couldn't figure it out. So any help will be great to find the next three numbers or letters. Here's the patters... DEGHNORY, EHILMU, HIILMTU, BEILLMRUY,... 50, 33, 25, 20, 16, 14, 12,... 1777, 1795, 1818, 1819, 1820, 1822, 1836, 1837.. A,H,I,M,O,T,... Answered by Chris Fisher and Penny Nom.
	What are the two numbers?		2001-09-24
		From A student: What are the two numbers. the sum of two numbers is 15. 6 times the smaller number is 4 times the larger number .find the two numbers. the sum of the two numbers is 28. 2 times the larger number is 5 times the smaller number minus 7. find the two numbers. Answered by Claude Tardif.
	David's wages		2001-09-24
		From Kimberlee: My math question is David earns $6.00 per hour plus $9.00 for every extra hour he works over 40 hours per week. If David earned $285.00 last week, how many extra hours did he work? Answered by Penny Nom.
	An acute scalene triangle		2001-09-24
		From Kim: Hi- I'm on a mission--I'm suppose to have a group of children write up a hypotheses about the altitudes and angle biscetors of the follwing 3 types of triangle--equilateral, isosceles and acute scalene triangle. Is there such a thing as a acute scalene triangle and why or why not. Answered by Chris Fisher.
	How much grass to mow?		2001-09-23
		From Jessica: The track and field area is 900 x 500 feet, including track and stands. The grass is mowed twice a week. 5,200 square feet of the sports area is not grass. Problem: How many square feet of grass are mowed each week? Answered by Penny Nom.
	Ciefficient of variation		2001-09-23
		From Carmen: I have a question from my OAC finite class. I've come across a problem with the coefficient of variation. I have taught my students that there are no units for coefficient of variation and it can be expressed as a percent. So, for example, a set of data with mean of 5 and standard deviation of 100 would have a CV of 5%. But what happens in this situation: the mean is 4meters and the standard deviation is 0.7mm. Is the CV 1.75% or 0.00175% or 0.0175%? I've had some students change leave the units as is, change them both to mm or change them both to meters...so which is it and why? Answered by Penny Nom.
	Solving trig equations		2001-09-22
		From Asad: Can you please explain to me how to solve trig Equations,e.g sin(x)=x4+12/2+cos(x)=x6+9/3= (if this can be solved) Answered by Claude Tardif.
	What percent of the sports drink was drunk by the women?		2001-09-22
		From Rachel: The male track and field athletes drank 153 gallons of sports drink at the meet. the track and field athletes drank 255 gallons of sports drink. The women track and field athletes drank 102 gallons. problem: What percent of the sports was drunk by the women? Answered by Penny Nom.
	4 digit combinations		2001-09-22
		From Laura: I need all of the 4 digit combinations using the numbers 0-9. Answered by Harley Weston.
	Standard deviation		2001-09-22
		From Doug: I was wondering if anybody knows who the founder of standard deviation was? Answered by Penny Nom.
	An egg shaped island		2001-09-22
		From Karen: I am a civil engineering designer trying to design an egg shaped island. I want a 30' radius at the top and a 40' radius at the bottom and the longest length of the egg to be 125'. Is there standard geometry for an egg shape? I am not held to exact radii or the length given. Answered by Chris Fisher.
	Milliters and grams		2001-09-20
		From Betty-jo: 500 ml is what in grams Answered by Pnny Nom.
	The square root of 20		2001-09-18
		From Dianna: How do you simplify a square root? My daughter tells me that the square root of 20 simplified is 5root4 Answered by Penny Nom.
	Solve for h		2001-09-17
		From Kim: s=2lw+2wh+2hl solve for h Answered by Penny Nom.
	4x(2x-1)+(2x-1)2		2001-09-17
		From Nick: how do u solve 4x(2x-1)+(2x-1)2 Answered by Penny Nom.
	A linear inequality		2001-09-17
		From Eric: How can I solve |x + y| + |x - y|< =6? Answered by Penny Nom.
	Counterclockwise		2001-09-14
		From Rolanda: When Descartes invented the coordinate system he decided to number them counter-clockwise. Why? Answered by Chris Fisher.
	300 pounds		2001-09-12
		From Cassie: HOW MANY KILOS IS IN 300 POUNDS? Answered by Penny Nom.
	A polygon		2001-09-11
		From Sueling: what is the smallest polygon. what is a polygon. Answered by Penny Nom.
	27		2001-09-10
		From Kacy: In class we were given this problem. We have the numbers 30, 29, 19,11,26. these numbers = 27 in some way but how? the numbers can be applied any way using + - / X ( ) but can only be used 1 time each. can you please help me. Answered by Claude Tardif.
	Combien 1.0 ml fait en metre cube		2001-09-10
		From M. Mauger: Bonjour, je voudrais savoir combien 1.0 ml fait en metre cube. Answered by Claude Tardif.
	Three fractions		2001-09-10
		From Kathleen: a/bc + d/ef + g/hi = 1 Each of three fractions has a one-digit numerator and a two digit denominator. The three fractions together add up to one. Place the nine digits 1-9 into the fractions to make the equation correct. Answered by Claude Tardif.
	The square root of 21/168		2001-09-10
		From A student: can you show me how to do this square root of 21/168 Answered by Penny Nom.
	Rolling two dice		2001-09-10
		From Owen: This probability question has been bugging me for a while. Two ordinary dice are rolled. If it is known that one shows a 5, what is the probability that they total 8? I have two different but (seemingly) correct solutions. Answered by Andrei Volodin.
	Arithmetic sequences		2001-09-10
		From Rachel: I can't seem to figure out a problem that deals with arithmetic sequencing. This is the question: The 5th term in an arithmetic sequence is 1/2, and the 20th term is 7/8. Find the first three terms of the sequence. I attempted this problem with the formula: An = a + (n-1)d (where the n represents the nth term, a is the first term, and d represents the common difference) I keep getting -9.5 for the first number, and then 3/120 as the common difference between the numbers. But as I have figured it, the sequence is getting greater and greater, and my data does not go with the terms given. Answered by Penny Nom.
	A 91-gon		2001-09-10
		From Ashley: Hi! My name is Ashley and I am an 8th grader and I couldn't find the name of a polygon with 91 sides. i was a question from my math teacher. Answered by Penny Nom.
	Integers		2001-09-09
		From A student: I am a Grade 9 student from Ontario Canada who has never understood how to do integers very well. I was wondering if you would be able to either send me some sites that will tell me how to calculate them in a simple way or if you would be able to write me back and give me some pointers. Answered by Leeanne Boehm.
	Double bar graphs		2001-09-09
		From Leslie: My daughter has a homework problem in which she is graphing data from two frequency tables onto a double bar graph. The graph shows how many students worked in a program in two different years, grouped by age. In the first age group, one of the years has no students working, while there were students in that age group in the other year. Answered by Penny Nom.
	Similar triangles		2001-09-08
		From Dave: I am standing on the bank of a river ( whose banks are parallel here) directly opposite a boathouse, B, on the opposite bank. I walk along the bank of the river past a signpost, S, until I reach a point C distant 60 metres from where I started walking. I then walk away from the bank, at right angles to the bank, until I reach a shady tree at D. Attached to teh tree is a sign stating that this spot is 45 metres from the signpost. C is 36 metres beyond S and B and S are in line from D. (a) How far did I walk away from the bank of the river?? (b) Calculate the width of the river? Answered by Penny Nom.
	Multiplying binomials		2001-09-08
		From A student: (x+1)(x+2)=? (2x-1)(x-4)=0 please tell me this question!! Answered by Leeanne Boehm.
	The best of 7		2001-09-08
		From Michelle: Professional basketball, hockey, and baseball championships are decided on the best 4 out of 7 games. The first team to win four games wins the championship. In how many possible ways could the team win the championship series after winning the first game? Example: Game 1 2 3 4 5 6 7 Result W L L W W W Answered by Leeanne Boehm.
	Divisibility rules		2001-09-07
		From A student: Why is it that when you add the digits of a number you can tell what the multiples of that number are. Example: 12131313111, 1+2+1+2+1+3+1+1+1=18, therefore 12131313111 is divisble by 2, 9, 18, & 3 because those numbers are divisble by 18. Answered by Penny Nom.
	Don't worry too much about your difficulties in math...		2001-09-07
		From Matt: Do you know who said,"Don't worry too much about your difficulties in math, I assure you that mine are still greater"? Thanks for your help. this for extra credit and I can't find it ANYWHERE! Answered by Penny Nom.
	0.999999=1?		2001-09-06
		From Catherine: Hi! My teacher told us that 0.9 repeating equals one. We discussed how this is true. But, I was wondering if there is a proof that this is true. If so what is this called? I was trying to find information, but, it's hard when you don't know the name. Answered by Walter Whiteley.
	Commas in numbers		2001-09-06
		From Mike: When did the Ontario Education system drop the use of commas in large numbers and replace with a space? Why? Answered by Walter Whiteley.
	Ray and Jane		2001-09-06
		From A student: If Ray and Jane live 150 miles apart and they both leave their house at the same time, Ray goes 30 mph the whole time and Jane goes 50 mph the whole time how many miles are they from Ray's house when they meet? And what is the exact travel time untl they meet. Answered by Penny Nom.
	I have 6 digits.		2001-09-06
		From Kristan: I have 6 digits. My hundred thousands is 1 less than my 1 digit, 8 greater than my thousands digit, twice my tens digit, and 4 times my hundreds digit. My ten thousands digit is 0. What # am I? Answered by Penny Nom.
	Sharing a donut		2001-09-06
		From Amanda: You have invited 11 people over to your house one day, and your friends are hungry. You go into the kitchen and find out you only have 1 donut (with a hole in the middle). In order to feed 12 people (including you), you must cut the donut into 12 pieces with only using a straight knife and cutting 3 times. This is NOT a trick question. Answered by Claude Tardif.
	Earthquake warning		2001-09-03
		From Dillon: In the city of Skangai there are 6 million people.Each person has to tell 2 more people that theres going to be an earthquake. After they do they leave the city. There will be no duplications.It takes 3 minutes to tell each person. How long will it take for the whole city to know about the earthquake? Answered by Penny Nom.
	72 cards		2001-09-03
		From A student: What would be the probability of dealing a deck of 72 cards out in the exact orderly sequence that they were in when they were packaged after they have been throughly shuffled? Answered by Andrei Volodin.
	Two snakes		2001-08-31
		From A student: Two snakes(pythons,actually)of same size and shape start swallowing each other by the tail with the same speed. What will happen ultimately? Answered by Claude Tardif.
	Joe and his dad		2001-08-28
		From Sarah: Joe Spout left a campsite on a trip down the river in a canoe, traveling at 6 km/h. Four hours later, Joe's father set out after him in a motorboat. The motorboat traveled 30 km/h. How long after Joe`s father started did he overtake the canoe? How far had Joe traveled down the river when his father overtook him? Answered by Leeanne Boehm.
	Water jars		2001-08-27
		From Pe3te: Stacie and Kacie each have a jar. Stacies jar holds 5 quarts of water and Kacies jar holds 3 quarts. The girls dad ask them to go get him some water from the pump and to get him 1 gallon of water (NO MORE NO LESS) The jars were not marked in any way. In ten minutes the girls where back with 1 gallon. How did they get exactly 1 gallon ? 1) there are two ways to do it I only no one. 1st answer is..... Answered by Penny Nom.
	Bisecting angles		2001-08-27
		From Monica: Ray QS is the bisector for angle PQR. Find the measure of angle PQS and PQR if the measure of angle SQR is 52 degrees. Answered by Penny Nom.
	A sequence		2001-08-25
		From Sharon: 1 11 21 1211 111221 312211 1311221 1113213211 31131211131221 13211311123113112211 What would be the next sequence of numbers? my name is sharon i work in customer service and a friend asked me to solve this. Answered by Walter Whiteley.
	Vertices		2001-08-08
		From Jordan: I am a fifth grader learning geometry with my mom's help, can you please explain what a vertices are?? Answered by Penny Nom.
	Fourier transform		2001-08-07
		From Adbul: Sir, we have the Dirichlet's condition for the Fourier transform : " The function should be integral over the real line " But why we are we neglecting this for example when we take the Fourier transform of an impulse train? Suppose we want to travel from one corner of a square of side 'a' to the diagonally opposite corner. We can travel along the sides which gives a pah length of '2a'. We can also do it in steps as shown below: _ | |_PATH | |_ |_____| Suppose The step size =DELTA x Then the path length will be again '2a'. Now in the limit DELTA x -->0 again we get '2a' But when we take the limit we get the straight line diagonal whose length is 'SQRT(2)X a' Where did I go wrong? Answered by Chris Fisher.
	How far does the fly fly?		2001-08-07
		From Harold: 6 MPH 4 MPH Rachel ---------------------- Eli 10 Miles apart The fly is on Rachels handlebars. The fly is scared so it flys back and forth at 20 MP H. How far has the fly flown when Rachel and Eli meet? f Answered by Penny Nom.
	Standard angles		2001-08-05
		From Nagaraj: Why 0o , 30o , 45o , 60o ,and 90o are taken as standard angles in Trigonometry? Why can't we take some other angles as standard angles? Answered by Chris Fisher.
	Conformable matrices		2001-08-05
		From Wayne: Can someone explain the concept of conformable matrices in a way that is easy to understand ? One definition says to multiply matrices rows and columns must conform, ie, 5 x 3 matrix times a 3 x 5 matrix. In the next example, however a 8 x 1 matrix and a 8 x 3 matrix are said to be conformable! Answered by Steve Kirkland.
	Linear regression		2001-08-01
		From A student and a mother: My mom is taking a correspondence course in Simple Linear Regression and Correlation Analysis and we've been arguing about the relationship between the correlation -rxy and standard estimate of error-Sy.x. I took statistics last year in high school and I remember something about the Sy.x being proportionate to the r. Are they inversely related, directly related, not related, or can only range from 0 to 1.00? Her book doesn't say very much and I believe they are inversely related. She says they're directly related. Answered by Chris Fisher and Penny Nom.
	Intersection of perpendicular cylindrical surfaces		2001-07-31
		From Charlie: Please consider two right circular cylinders, perpendicular one to the other, and of unlike radii in a 3 dimensional Cartesian space with mutually perpendicular x,y,z axes. If one cylinder is centered on the y axis with radius ra, and the other on the z axis with radius rb, then the expression for the first surface would be x2 + z2 = ra2, y = any number. Likewise, the second cylinder's surface would be x2 + y2 = rb2, z = any number. It is my intent to define the curve at the intersection of these two cylindrical surfaces. From sketching the conditions it appears that this intersection resembles an ellipse folded about its minor axis. Answered by Chris Fisher.
	The radius of a planet		2001-07-30
		From Jessica: A satellite is orbiting the earth at an altitude of 100 miles. If the angle of depression from the satellite to the horizon is 50 degrees, what is the radius (to the nearest mile) of the planet? Answered by Harley Weston.
	1996^1999 and 1999^1996		2001-07-29
		From Rajesh: what is greater 19991997 or 19971999? Answered by Chris Fisher.
	The best linear model		2001-07-29
		From Rebeca: I am a student (senior) summer hire working for Dept of the Army Resource Management. I've been assisting the Analyst in developing a model to predict training costs. The technique we used was simple linear regression. Now I've been asked for my opinion in choosing the best model I feel is better. I've chosen #1. Garrison Training but I want a second opinion before I give my choice. I've taken basic statistics last year in high school and will probably be taking more this year. Could you look over the information and give me a reason my choice would not be best? The dep variable-y, is Training costs in dolars per day. Model Ind Variable- X a b r sy.x 1. Garrison Training 126.31 0.982 0.9055 117.2 2. Local Training 212.16 1.37 0.7937 142.7 3. Man Rig Area 116.38 2.47 0.6481 175.6 4. Major Training 346.12 4.67 0.7280 167.2 Answered by Andrei Volodin.
	e^pi > pi^e		2001-07-27
		From Dusty: What book(s) contain a proof that ePi > Pie? I think it might be in Problems in Analysis published by Springer-Verlag but I have not been able to check. Answered by Chris Fisher.
	A trig identity		2001-07-27
		From Jeff: prove this identity and show steps tan(x/2+pi/4)=secx+tanx Answered by Harley Weston.
	Radian measure		2001-07-26
		From Amy: i have to find out what is meant by the radian measure of an angle and compare it to the measure of an angle in degrees. Answered by Harley Weston.
	The Mean Value Theorem		2001-07-23
		From Corrie: I need to find if the mean value theorem exists. and if so, find all values c guaranteed by the theorem. f(x) = |x2-25| on the interval [-10,0] Answered by Harley Weston.
	What did the girls score on average?		2001-07-20
		From Rajesh: The students of two schools were sitting the same test. The students attending the first school scored 74 on average; within this the average scores of the boys and the girls were 71 and 76, respectively. The corresponding scores in the other school were 84, 81 and 90, respectively. If the average score of all boys was 79, what did the girls score on average? Answered by Penny Nom.
	Matrix reconstruction		2001-07-19
		From Guy: Is there a way to get the sums of rows, columns and diagonals of an n x n matrix to reconstruct the original matrix? Answered by Walter Whiteley and Patrick Maidorn.
	Hours worked		2001-07-18
		From Carlos: I have a simple question:whats the formula to transform time into decimals? more exactly im working on a spreadsheet and i want to be able to type in for example hours worked: 11- 11:30 pm and a formula would tell me 12.5 hours how do i do it? Answered by Patrick Maidorn.
	Generating uniquie 2 digit numbers		2001-07-16
		From Anthony: What methodology can I use to generate uniquie 2 digit numbers from unique 7 digit numbers. Of'course the total number of 7-digit numbers is not greater than 99. Answered by Penny Nom.
	Rhombus		2001-07-16
		From William: Calculate the internal angles of a rhombus given measurments of all four sides only. Answered by Walter Whiteley.
	Margin of error		2001-07-13
		From Jim: If a survey was completed by four different groups of people as indicated below what would the over-all margin of error be for this survey given the fact that the number of people in each group were different? Group # polled Margin of error A. 779 +/- 4% B. 315 +/- 7% C. 323 +/- 6% D. 254 +/- 9% Answered by Andrei Volodin.
	6,000,000,000,000,000,000		2001-07-12
		From James: How would I express 6,000,000,000,000,000,000 in words? Answered by Leeanne Boehm.
	The speed of the boat		2001-07-12
		From Sharon: A motor boat is travelling in a southeasterly direction in water that is flowing from the south at 2km per hour. Show that the speed of the boat is (6 times the square root of 2) km per hour, given that it can travel at 10km per hour in still water. Answered by Penny Nom.
	Comparing means and standard deviations		2001-07-11
		From Shelly: Is there a way to compare means and standard deviations that come from different size samples? Is there an equation that can normalize sample size? Answered by Andrei Volodin.
	Investing $5,000		2001-07-09
		From A student: A principal amount of $5,000 was invested in a savings account for 5 years.The interest earned was $500.Use the simple interest formula to find the annual rate of interest. Answered by Penny Nom.
	Cakes and ribbons		2001-07-05
		From Jennifer: A cake recipe calls for 3 1/4 cups of flour. You already put in 1 3/4 cups. How much more should you add? You have 3/4 yard of ribbon. How many 1/8-yard pieces can you cut the ribbon into? Answered by Penny Nom.
	Some irrational numbers		2001-07-03
		From Kellie: Is it possible to write pi as a fraction? Is it possible to write the square root of 2 as a fraction.. Explain why? Answered by Harley Weston.
	Arclength of an ellipse		2001-07-03
		From A hobbyist: What is the equation (with the length of the arc as a variable) for one quadrant of the ellipse,... Answered by Claude tardif.
	A confidence interval		2001-06-28
		From Murray: An investigator wants to find out of there are any difference in "skills" between full and part time students. Records show the following: Student Mean Score Std Dev Number ---------- ----------------- ---------- ----------- Full time 83 12 45 Part time 70 15 55 Compute a 95% confidence interval for the difference in mean scores. Answered by Andrei Volodin.
	Three chords		2001-06-28
		From Paul: AE is a diameter of a circle and AC, CD and DE are chords of lengths 1, 2 and 3 respectively. (See the diagram.) Find the ridius of the circle. Answered by Harley Weston.
	Three tangents to a circle		2001-06-27
		From Stephanie: The three lines PS, PT, and RQ are tangents to the circle. The points S, X, and T are the three points of tangency. Prove that the perimeter of triangle PQR is equal to 2PT. Answered by Chris Fisher.
	A three legged stool		2001-06-27
		From Teri: I wanted to know why a three legged stool is always steady, and why a four legged stool is not. I am wanting to know the mathematical reasoning behind this. Answered by Walter Whiteley.
	A phone bill		2001-06-18
		From Janet: What is the formuala to calculate cost per minute? Here is the data below # of calls - 238 # of minutes - 443 cost - $70.06 Answered by Penny Nom.
	Two log problems		2001-06-16
		From A student: Hi..this is one of 9th grade student in Fort Worth TX. well..I am doing EPGY stuffs in my school right now..and.. me and my teacher had problems to solve some advanced logarithmic thing. so I searched some sites to solve these two questions (log base 7 * 10) * (log base 10 * X ) = 2 log base 10 * (3x-4) + log base 12 * X --------------------------------------------------- (log base 12 * 2) + (log base 12 * 5) = log base 10 *4 Answered by Harley Weston.
	A calculation with 6 numbers		2001-06-16
		From Edwin: I'm asked to come with, and program (in Ansi -C) an algorithm that calculates all the possible results of a calculation with 6 numbers and one result. For example: I want all calculations with the numbers 3, 3, 8, 8, 2, 9, and with a result of 786. all numbers may be used once, arithmetical operations allowed are + - / *, fractions are not allowed. The problem here is what is a fast method to do this (i.e. what's algorithm that can to this). Answered by Claude Tardif.
	A factoring problem		2001-06-14
		From A student: What is the factoring of x squared -7+6 equal Answered by Penny Nom.
	Primes and square roots		2001-06-14
		From Paul: I have a bit of a math problem. It has to do with determining if a very large number is a prime. One method entails dividing the number by every smaller prime number. If any divide into it, it's not a prime. This would be a big job if the number was something like 400 digits long. Another way I read about was to take the square root of the number and test all the primes less than its square root. The explanation went like this: "When a number is divided by another number that is greater than its square root, the result is a number smaller than the square root. For example, the square root of 36 is 6. Dividing 36 by 2, a smaller number than 6, gives 18, a number that is larger than the square root. To prove that 37 is prime it is only necessary to divide it by primes less than 6, since if it had a prime factor greater than 6, it would have to have one less than 6 as well." I understand the explanation, up to the last sentence. I fail to see the underlying logic. Why if a prime factor exists below the square does one have to exist above the square too? The number 40 can be divided by the prime 2, a number below its square root, but no other primes can do this above its square root. Have I missed something? What's the logic here? Answered by Claude Tardif and Penny Nom.
	Euclid and Pythagoras		2001-06-14
		From Scott: Question 1. In about 300 BC Euclid recorded a proof of Pythagoras rule. Disscuss Euclid's contribution to developing the theroem. Question 2. Why was it named after Pyhagoras if he did not orginally discover it? Answered by Chris Fisher.
	Area between curves		2001-06-13
		From Phil: question 1 find the area bound by the curves y = x2 + 2x + 3 and y = 2x + 4 question 2 Find the volume generated by rotating the curve x2 + y2 = 9 about the x-axis Answered by Harley Weston.
	An inequality involving triangles		2001-06-12
		From Sandra: The triangle inequality guarantees that the sum of the lengths of two sides of a triangle is greater than the length of the third. As a consequence, if x and y are legs of a right triangle, with x less than or equal to y, and z the hypotenuse, then x + y is greater than z, so x is greater than z - y. Under what circumstances will x is greater than 2(z - y) be true? Answered by Chris Fisher and Penny Nom.
	Monthly payments		2001-06-12
		From Anthony: This question is base on my interest. I would like to know the formula for calculating this example: If you borrow $10,000 from a bank with an APR of 11.7% to be paid off in 5 years, what is your monthly payment? Answered by Penny Nom.
	5+5+5=550		2001-06-11
		From Tom: I am in algebra and my teacher gave us an equation that was not true. she told us that we could only use one line segment(it can't bend turn has to be straight) to make the equation true. here is the equation: 5+5+5=550. i have not figured it out but have tried many things and believe it is not mathmatical but cross a # or sign out.also i forgot you can't put a slash mark through the equals sign. Answered by Penny Nom.
	Geometry problems involving triangles		2001-06-07
		From Sandi: Find the radius of the largest circle contained in a right triangle whose legs are 8 and 15 and hypotenuse is 17. If the right triangle has legs a and b and hypotenuse c, find an expression for the radius of the circle. Answered by Penny Nom.
	Election in Angletown		2001-06-07
		From Zoe: At the last school election in Angletown 4620 votes were cast. Candidate Acute received 236 more votes than Candidate Obtuse. Candidate Right received 698 votes more than Candidate Acute. Candidate Straight received 256 votes less than Candidate Right. How many votes did each receive? Answered by Penny Nom.
	Buying a car		2001-06-06
		From Steph: How do you figure a percent. Say you want to buy a car listed for 21,500. You tell the dealer you want to pay 19,600. The dealer says they'll sell it to you for 20,450. how do you figure what the percent is between 20,450 & 19,600? Answered by Penny Nom.
	Danging couples		2001-06-06
		From Danielle: How many boy-girl dancing couples could be formed if 85 boys and 102 girls attend a school dance? Answered by Penny Nom.
	Exponential form		2001-06-06
		From A student: Hello can u please answer my question what is the exponent form of 8x8x8x8 Answered by Penny Nom.
	Securing a plank in four dimensions		2001-06-06
		From Becca: If it takes two nails to secure a plank from rotating on a wall in the third spatial dimension, how many nails would it take if you were attempting to secure the board from rotating in the fourth spatial dimension? Answered by Walter Whiteley.
	Mutually exclusive		2001-06-05
		From Marje: What does the mathmatical term "mutually exclusive" mean. Pleas diagram if possible. Answered by Penny Nom.
	The shortest distance from a point to a line		2001-06-05
		From Kat: Find the shortest distance from the given line. Round to the nearest tenth. (-2,-1) and x+5y+20=0 Answered by Penny Nom.
	Where is the other $1?		2001-06-05
		From Samantha: 3 people go to a motel. The room is $30. They split it $10 each. While in the room the Mgr. tells the clerk the room was only $25, so he gives her $5 to take back to the 3 people. On the way she cant decide how to split the $5 between the three people so she puts $2 in her pocket and gives them $1 each.....Therefore, the room now only cost the three people $9 each, which is $27 plus the $2 the clerk pocketed,making a total of $29.....Where is the other $1? Answered by Leeanne Boehm.
	Two jugs		2001-06-04
		From Heather: One goes to a source of water with two jugs and only two jugs. One jug had a capacity of exactly three pints and the other five pints. Both jugs are opaque (you canít see inside them) and irregularly shaped. How can you use the two jugs and only the two jugs to measure exactly four pints of water? Answered by Harley Weston.
	Conservation, consumption and population growth		2001-06-04
		From Steve: I'm trying to quantify the relation between conservation/consumption and population growth. For instance let's consider California: The 2000 census states that California's population grew from 29,760* in 4-1990 to 33,871 in 4-2000. I want to find r or rate of growth per year. Based on the exponential growth formula for population growth: . . . Answered by Penny Nom.
	Common solution		2001-06-02
		From Samantha: Solve for common solution: x+y=6 2x-3y=2 Solve for y in terms of x: 3x-y=4 Answered by Penny Nom.
	Four digit numbers from 1,2,3,4,5,6,7,8		2001-05-31
		From Katie: Okay.......here's my question...how many different ways can you form a four digit number out of these digits..1,2,3,4,5,6,7,8? This is how my teacher said to do this.... 8*8, 7*7,6*6,5*5,4*4,3*3,2*2,1*1. then she said to add up the products and to multiply by 7. is this correct, and if not how can you figure this out. Answered by Penny Nom and Claude Tardif.
	Chickens and sheep		2001-05-31
		From Monica: Farmer Bob of the Martian Colony counted his sheep and chickens in an unusual way. When he finished, he reported that he had counted 86 feet and 26 heads. Use a guess and check table to find how many sheep and chickens are owned by the famer. Answered by Paul Betts and Penny Nom.
	Three goldfish		2001-05-30
		From Nathan: A man has three goldfish. When the youngest goldfish was born, the oldest fish was three times the middle fish's age. Nine years ago the oldest fish's age was the sum of the two other fish's ages. How old are the three goldfish? Answered by Penny Nom.
	Multiplication		2001-05-30
		From Lindsay: Who came up with multipling? its so easy Answered by Claude Tardif and Penny Nom.
	Your DJ Business		2001-05-30
		From Linda: Your DJ Business has 6 rap, 10 rock, 6 alternative, 8 oldies, and 5 country CD singles. How many different 10-song sets can the DJ play, if she plays 2 singles from each category? and How many different 10-song sets if she plays exactly 3 rap singles and 4 rock singles in each set? Answered by Leeanne Boehm.
	Jim's poker game		2001-05-24
		From Nick and Karnal: One day jim played poker with some of his friends and lost half his money.the number of dollars he had before the game was the same as the number of cents he had after the game, and the no of cents he had before the game was twice as much as the number of dollars he had after the game.how much money did he have before thegame??? Later that day jim met a friend Al on the street."hi al!Do u have any change on you al?""yes" "Good!can u give me a change of a dollar?" "I am afraid not!" "Then give me change of 50 cents.""I am sorry i cant." "how about a change of a quarter?""not possible." "a dime." "also not" "a nickel?" "not even that." al had no bills or silver dollars on him.whats the largest amount of cash he could have had? hope u can help me. Answered by Penny Nom.
	Pi		2001-05-24
		From Mary: Where does the term pi come from and how many digits are actually in pi? Answered by Penny Nom.
	New Quebec reform		2001-05-24
		From Marie-Andrée: I am a middle school teacher beginning to adapt to the new Quebec reform. I am regularely doing projects in écologie and géographie in French immersion based on the international schools way of thinking (What form does it have? How does it work? What is its history? How does it change? How is it linking to our lives? What is our responsibility about that fact or that thing?) and I have real difficulty to make it work for math. So now, I am looking for math concepts (8) which would link to the same way of thinking. What are your suggestions? Answered by Claude Tardif.
	SPRT		2001-05-24
		From A researcher: I have a medical-pharmaceutical study that says: SPRT (something to do with Secuential and Truncated). Do You know what it means S.P.R.T. and what it is? Answered by Ejaz Ahmed and Penny Nom.
	The diameter of an oval		2001-05-23
		From Tim: Is there a such thing as a diameter of a oval? If not, is there a way to get the circumference? Answered by Claude Tardif and Penny Nom.
	Harmonic numbers		2001-05-23
		From Leslie: The harmonic numbers Hk, k = 1,2,3.....are defined by Hk = 1 + 1/2 + 1/3....1/k I am trying to prove by mathematical induction: H2n >= 1 + n/2 , whenever n is a nonnegative integer. H8 = H23 >= 1 + 3/2 Can you help? Answered by Harley Weston.
	How many sides does a circle have?		2001-05-16
		From Georganne: How many sides does a circle have? My son answered "infinate" on a test and was corrected. The school insists the answer is 0. Answered by Chris Fisher and Denis Hanson.
	A 6 character field		2001-05-16
		From A parent: I have a 6 character field that can use any combination of alpha-numeric characters (A-Z, 0-9). How many total combinations are possible? Answered by Penny Nom.
	Quadratics		2001-05-16
		From John: I am in the final stages of a math project and I need to interview an expert for the last part. Please try to answer at least a few of these questions. How do you use quadratic equations in your everyday life? Do you find being a math expert very helpful in life? Is the quadratic equation useful to you? Why did you decide to become a math expert? What do you think is the most important function of the quadratic equation? Answered by Harley Weston.
	25 y^2 + 20 y z - 4 z^2		2001-05-15
		From Kimmy: i don't know how to factor the trinomial 25y2 + 20yz - 4z2. I can get it, but i get messed up on getting the minus 4 at the end. all i get is a plus 4. Can it even be factored. Answered by Penny Nom.
	A pile of sand		2001-05-14
		From Gul: Sand for use on icy roads is stored in a conical pile 14.2 m high and with a base diameter of 34.4 m calculate the volume of the pile if one sander can take 6.9 m of sand, how many sanders can be filled from the pile? Answered by Penny Nom.
	A triangular pyramid		2001-05-14
		From Kumar: In a Pyramid OABC, all the three sides of the base: a, b, c are known. Also known are the angles between the three sides from the vertex O: Angles AOB, BOC, COA. With this information, is it possible to calculate the lengths of the three sides: OA, OB & OC. Answered by Chris Fisher.
	Manifolds		2001-05-14
		From Thierry: Maybe you could help me, because I have serious problems for the translations of an English mathematic word which is "MANIFOLD". It's impossible to have a clear translation in French. Do you have a solution? Answered by Claude Tardif.
	Toy bricks		2001-05-13
		From Sarah: A regular-sized brick weighs 4 kilograms. How much will a similar toy brick, made of the same material, but all of the same dimensions of which are four times smaller, weigh? The 300-metre tall Eiffel tower is made of steel and weighs 8 000 000 kg. An exact replica, made of the same material, weighs 1 kg. How high is the replica Answered by Penny Nom.
	Simplifying algebraic expressions		2001-05-12
		From A student: How do you simplify algebra expressions? Answered by Penny Nom.
	The height of a pyramid		2001-05-11
		From Ryan: Jane is building a model of a pyramid for a history project. It has a square base of side length 100 cm. The angle of elevation of the sides is 60 degrees. What is the height of Jane's pyramid. Answered by Harley Weston.
	The angles in a triangle		2001-05-11
		From Nikki: Find the measure, to the nearest degree, of each angle of a triangle with sides of the given lengths. 26, 35, 40 Answered by Penny Nom.
	A quadratic function		2001-05-10
		From A parent: A quadratic function is given by f:x------ax2+b If the two points A(2, 2) and B (0, -8) are on the graph of the function, then find a and b. Answered by Penny Nom.
	Greatest Common Factor		2001-05-09
		From Nicole: What is the Greatest Common Facter for: 126,261 1008,1080 546,1995 128,256 and 255,256 Answered by Penny Nom.
	Circles, ellipses, parabolas and hyperbolas		2001-05-09
		From Colleen: How is an ellipse like a circle? In what way does an ellipse have a center? How is a hyperbola similar and different to an ellipse? How is a parabola similar a different to a circle ellipse and parabola? Answered by Pnny Nom.
	Marginal Propensity to Consume		2001-05-09
		From Esther: The derivative of the national consumption function C = f(y) is called the ____________________. Answered by Judi McDonald.
	National consumption function		2001-05-09
		From Brian: If consumption is $11 billion when disposable income is 0 and the marginal propensity to consume is dC/dy = 1/(2y+4)1/2+0.3(in billions of dollars), find the national consumption function. Answered by Harley Weston.
	Maximize profit		2001-05-09
		From Brian: The marginal cost for a certain product is given by MC = 6x+60 and the fixed costs are $100. The marginal revenue is given by MR = 180-2x. Find the level of production that will maximize profit and find the profit or loss at that level. Answered by Harley Weston.
	Dividing fractions		2001-05-09
		From Rina: I just wanted to ask if you could help me in math. See I'm having a test soon and its on Dividing Fractions and I just don't get it. My math teacher says that I'll be just fine but I failed my math quiz. I went to ask eric but they could help me so they told me to go to you. So here I am asking you if you could help me. Answered by Penny Nom.
	The area between two curves		2001-05-08
		From Esther: Find the area of the region enclosed by the graphs of y = x3-6x and y = -2x between their points of intersection. Answered by Harley Weston.
	The average value of a continuous function		2001-05-08
		From Esther: The average value of a continuous function y = f(x) on the interval [a,b] is given by ________________? Answered by Harley Weston.
	Neither prime nor composite		2001-05-08
		From Marc: what 2 numbers are neither prime nor combitative? Answered by Penny Nom.
	Teaching square roots		2001-05-08
		From Katie: My friend and I are doing a project. We have to teach our class about square roots. What is the easiest way to teach square roots to a class? Answered by Penny Nom.
	24 from 2, 2, 14, and 21		2001-05-08
		From Kimberly: using the numbers 2, 2, 14, and 21. how can you get 24 using + - X or division Answered by Claude Tardif.
	Taking matches		2001-05-05
		From Mark: Two piles of matches are on a table. A player can remove a match from either pile or a match from both piles. The player who takes the last match loses. If there are two players, how should you play? Answered by Claude Tardif.
	Probabilities and dice.		2001-05-04
		From Carmen: Hi! My name is Carmen! I am a member of a grade 5 class in Edmonton, AB. We were talking about probability in math, and I was wanted to know what the probability (odds) of rolling two sixes would be rolling two dice? If it is not to diffucult could you tell me what the probability (odds) of rolling any number with two dice were? Answered by Andrei Volodin and Penny Nom.
	How many acres are in a square mile?		2001-05-04
		From Terri: How many acres are in a square mile? Answered by Judi McDonald.
	Adding and subtracting rational expressions		2001-05-03
		From Donna: Adding and subtracting Rational expressions. I am in grade 10 and I am a student here is an example of the questions: 1/(x+1) - 1/(x-1) = ? Answered by Penny Nom.
	Are you overweight?		2001-05-03
		From Oneita: How do I square a number.....? My problem is : square your height in inches and take 4.25 percent of the result to determine if you are overweight. Answered by Claude Tardif.
	Logs for the fire		2001-05-02
		From Tom: Three girls named Amanda, Beatrice, and Cleo visit a summer cottage. Amanda brings 5 logs for the fire, Beatrice brings 3 logs and Cleo contributes 80 cents. How should the money be divided among the other two girls so that each of the three is felt to have contributed equally to the cost of the fire. Answered by Penny Nom.
	Graphing equations		2001-05-01
		From A student: If, for example, 4x2-12x+9=0 and -4x2+12x-9=0, which I'm assuming it does since you can derive that equation from the first, why do those two equations have different graphs? Answered by Penny Nom.
	Tiling a floor		2001-05-01
		From Sarah: Cut out of paper or cardboard a quadrilateral having no two sides parallel, no two sides of equal length and no indentations. Can an endless floor be tiled with copies of such a figure? Answered by Claude Tardif.
	Area of a regular polygon		2001-05-01
		From Carl: What is the formula for finding the area of a regular Hexagon and a regular Pentagon Answered by Penny Nom.
	Population growth		2001-05-01
		From Gina: Suppose the population of a country increases at a steady rate of 3% a year. If the population is 50 million at a certain time, what will it be 25 years later? Define the recurrence relation that solves this problem. Answered by Penny Nom.
	Average speed		2001-05-01
		From Tom: A ship goes in one direction, west to Hawaii, at 20 nautical miles per hour and, because of the wind, makes the return trip at 30 nautical miles per hour. What is the average speed? Answered by Claude Tardif.
	Typing a project		2001-05-01
		From Tom: Two students have to type a project. One can do it in 2 hours. It would take the other student three hours. They have 2 type writers. How fast can they finish by working simultaneously? Answered by Claude Tardif.
	A sequence defined recursively		2001-05-01
		From A student: A sequence s is defined recursively as follows: s0=1 s1=2 sk=2sk-2 for all integers - Compute s2,s3,s4... to guess an explicit formula for the sequence sk. Answered by Penny Nom.
	A sequence of even terms		2001-04-29
		From A student: A sequence c is defined recursively as follows: c0 = 2 c1 = 4 c2 = 6 ck= 5ck-3 for all integers Prove that cn is even for all integers. Answered by Leeanne Boehm and Penny Nom.
	Dominos		2001-04-28
		From Mark: A standard dominoe set consists of 28 pieces, from double-zero to double-six Is it possible to arrange all those pieces in a straight line in such a way that the dots of any pair of adjacent pieces match? Please include picture Is it possible to arrange them in a circle and still meet the conditions in 1? Answered by Claude Tardif.
	Choosing a car		2001-04-28
		From Ashley: THE CAR DEALERSHIP IN TOWN OFFERS 32 DIFFERENT MODELS OF VIHICLES.EACH MODEL HAS A CHOICE OF EIGHT INTERIOR COLORS,EIGHT EXTERIOR COLORS,AND ALSO THE OPTION OF AUTOMATIC OR MANUAL TRANSMISSION. HOW MANY COMBINATIONS ARE POSSIBLE? Answered by Penny Nom and Andrei Volodin.
	A Taylor series		2001-04-27
		From Karan: Given the following information of the function f''(x) = 2f(x) for every value of x f(0) = 1 f(0) = 0 what is the complete Taylor series for f(x) at a = 0 Answered by Harley Weston.
	Triangles and fractions		2001-04-27
		From Constance: My name is Constance and I am thirteen years old (I am a student). The question that I am queering about I don't understand why you do ONE HALF x the base x the width WHEN YOU WANT TO FIND the area of a triangle? My second question is if you multiply one half and 10 together why does it come out as 5? Answered by Penny Nom.
	Lots of coins		2001-04-26
		From A student: I purchase 2 million coins at 9.75 I purchase 1 milion coins at 8 what is the formula to calculate my average cost? Answered by Penny Nom.
	A confidence interval		2001-04-26
		From Kim: A poll asked 1528 adults if they were in favor of the death penalty, 1238 said yes, find 99% confidence level for percent of all adult who are in favor of the death penalty. Answered by Andrei Volodin.
	How many 6 digit numeral combinations		2001-04-26
		From Bryan: How many 6 digit numeral combinations are there If you can only use 6 digits (1, 2, 3, 4, 5, 6) and no number can be used twice in the Numeral! Answered by Claude Tardif.
	Working together		2001-04-26
		From Stephanie: Tom takes 10 hours to piant a mural on the wall of Evergreen School. Carol takes 6 hours to do the same job. If they work together, how long will it take them to paint the mural? Answered by Claude Tardif and Penny Nom.
	Tonya in the orange grove		2001-04-25
		From A parent: Tonya was helping in the orange grove. She decided to take some oranges home to share with 3 friends. She gave 3 more than half to Jennifer. Angela got half the remainder and 3 more. She gave Josie half the remainder plus three. When she got home, she had only 10 oranges left. How many did she have when she left the grove? Answered by Penny Nom.
	A lemon and a recall		2001-04-25
		From Katie: A Man has two cars, a recall and a lemon. The probability that the recall starts is 10%. The proabability that the lemon will start is 5%. What is the proabability that both cars will start? Answered by Andrei Volodin.
	Expected value		2001-04-24
		From Cindy: A game consists of rolling a single fair die. If a number great than 4 is rolled you win the number of dollars showing on the die. If any other number is rolled, you receive $1.00. What is the expected value of this game? Answered by Andrei Volodin.
	Squares of Fibonacci numbers		2001-04-24
		From Vandan: What discoveries can be made about the sum of squares of Fibonacci's Sequence? Answered by Penny Nom.
	Writing in the math curriculum		2001-04-23
		From Wendy: I am trying to incorporate more writing into my math curriculum. I am currently using journals and activities which involve written explanations. Any new ideas on how to involve my students more in the writing process in math class? Answered by Walter Whiteley.
	A few problems		2001-04-22
		From Carol: Hello I am a College student trying get through my elmentry concepts class. I am also working with the middle and elementry school student with their work. I was given a few problems to work on and i am having a hard time explaining them to students. DO you think you can help with a coupld of these questions! Answered by Penny Nom.
	Oil revenue		2001-04-21
		From Brian: Suppose that t months from now an oil well will be producing crude oil at the rate of r(t), not a constant, barrels per month and that the price of crude oil will be p(t), not a constant, dollars per barrel. Assume that the oil is sold as soon as it is extracted from the ground. Find an expression for the total revenue from the oil well, R(t). A certain oil well that currently yields 400 barrels of crude oil a month will run dry in 2 years. The price of crude oil is currently $18 per barrel and is expected to rise at a constant rate of 3 cents per barrel per month. What will be the total revenue from this well? {Hint: Model the degraded production rate with the equation: r(t) = (A-Bt)e0.04t} Answered by Harley Weston.
	Five		2001-04-21
		From Billie: If One is single, two is twin, three is triple, four is quadruple, five is ????? what is five and where would I find the rest of the numbers,six, seven, eight, nine, etc. Answered by Penny Nom.
	Repeating decimals		2001-04-21
		From Sarah: Hi, I'm working on a project for school. The theory I choose was "When turned into a fraction, a repeating decimal has a denometor that is a multiple of three." I have a couple of questions about this topic. My first question is, have you ever heard of this, and what can you tell me about it? My second question is, when I was testing this theory I came across .999... now, when this is a fraction it is 9/9 which is equal to one. The denometor is a multiple of 3, but it's a whole number. I don't understand how a decimal can be equal to a whole number since a decimal is a piece of a whole number. Please don't just show me a math problem, I don't want to see a math problem. I want to see an explanation of this theory and the decimal .999... Answered by Penny Nom.
	Geometry		2001-04-21
		From Rebecca: How do you prove the following: Let CD be an altitude of triangle ABC and assume that angle C=90 degrees. Let r1 and r2 be the inradii of triangle CAD and CBD, respectively, and show that r+r1+r2=CD, where r is the inradius of triangle ABC. Answered by Chris Fisher.
	Two boats		2001-04-19
		From Pat: Two boats head directly toward each other, one of them traveling 12 miles per hour and the other traveling 17 miles per hour. They begin at a distance of 20 miles from each other. How far apart are they one minute before they collide? Answered by Penny Nom.
	Pyramids		2001-04-18
		From Kelly: I'm in tenth grade and I know that there's some formula for finding out the slope of the side of a pyramid. I thought it could be the pythagorean therom, but I'm not sure if this works. Please send me the formula as soon as possible, I need it for a project. Answered by Penny Nom.
	A geometry proof		2001-04-18
		From Melissa: Extend the bisectors of angle A, angle B, and angle C of triangle ABC to meet the circumcircle at points X, Y, and Z respectively. Show that I is the orthocenter of triangle XYZ. Answered by Chris Fisher.
	The number of occurrences of 0 is __, of 1 is __, of...		2001-04-17
		From Martyanne: "In this sentence the number of occurrences of 0 is __, of 1 is __, of 2 is __, of 3 is __, of 4 is __, of 5 is __, of 6 is __, if 7 is __, of 8 is __, of 9 is __." Each blank is to be filled with a numeral of one or more digits, written in decimal notation. Answered by Claude Tardif.
	Isoscles and scalene		2001-04-17
		From Autumn: explain where the term isoscles and scalene came from? Answered by Chris Fisher.
	Differentiation		2001-04-17
		From Esther: Could you please tell me what the first derivative is of the following: y = 2/(2x+e2x) Is it (1+xe2x)/(2x+e2x)2 or perhaps -4(1+e2x)/(2x+e2x)2 ? I am a little confused between the two! Answered by Harley Weston.
	Solving some equations		2001-04-16
		From Justin: Solve the following equations for x x+7=10 x= x-7=10 x= 3x=7 x= x/3=10 x= . . . . Answered by Penny Nom.
	Leukemia		2001-04-15
		From Don: Assume: Leukemia occurs at an incidence of 1 in 10,000. Benzene is a known carcinogen which causes Leukemia and has been found in toxic levels in the homes of a community of 1200 people. Question: How many cases of Leukemia would be necessary to reject the null hypothesis. That is, to suggest that statistically, the cases are more likely due to benzene exposure rather than chance. Answered by Chris Fisher and Penny Nom.
	Constructing an equilateral triangle		2001-04-14
		From Peggy: Please send directions to make an equilateral triangle in plane geometry. I want each student to draw two, cut them out, and place them together to form a Jewish Star. Answered by Penny Nom.
	The sides of an octagon		2001-04-13
		From Craig: How do I figure the length of the sides of an octagon when all I know is the diameter (4.375). Answered by Penny Nom.
	1 = 0.999...		2001-04-13
		From Joan: I have a middle grade math question for you. I would like to know why .9999... = 1 ? I can not use algebra to show this or the following: We agree that 2 = 2 and that 2-2 = 0, so 1.00000...... -0.99999..... ---------------- 0.000000...... and 0.000... = 0 therefore 0.9 = 1 ----------OR--------------- 1/3 = 0.333333 and 3 X 1/3 = 1, so if 3 X 0.333... = 0.999... then 0.999... = 1 My teacher says that I can not use the above example to show why this is true, and that I must use a couple different examples. He says that there are several other ways. Do you know any? I could really use the help because I can't think of any other ways to show this is true. Thanks for any help you can give. Answered by Penny Nom.
	Squares on a chess board		2001-04-11
		From Tom: It was once claimed that there are 204 squares on an ordinary chessboard (8sq. x 8sq.) Can you justify this claim? "PLEASE" include pictures. How many rectangles are there on an ordinary chessboard? (8sq. x 8sq.) "PLEASE" include pictures. Answered by Penny Nom.
	Compound interest		2001-04-11
		From A student: What principal will grow to $1367.10 after 1 year at 10% compounded semi-annually? Answered by Claude Tardif and Penny Nom.
	Prisms		2001-04-10
		From A fourth grade class: A fourth grade class is curious about the names that have been given to various solid geometric figures based on their shapes: are there names for solids based on a rhombus, a trapezoid, a parallelogram, a decagon, and/or a quadralateral? Answered by Chris Fisher.
	Parabola problems		2001-04-10
		From Kathleen: Graph each function and state its domain and range. y = 3x2 + 4 For each parabola find: i) the direction of opening ii) the coordinates of the vertex iii) the y-intercept iv) the x-intercepts y = x2 + 3 Find the equation of each parabola vertex at (0, -2) and passing through the point (3,7) Answered by Harley Weston.
	Integration by parts		2001-04-09
		From A student: how do you integrate x tan-1x dx, i know it can be done by integration by parts maybe, but i'm not sure.... Answered by Claude Tardif and Harley Weston.
	The domain of a function		2001-04-08
		From Mina: Let f(x) = (2x2+3x-17)/(x+5) What is the domain of f? What are the values of x for which f'(x) does not = 0? Answered by Harley Weston.
	The normal to a curve		2001-04-08
		From Varenne: I am having SO much trouble tackling this question and don't know what the right answer is... can you help me out? The question is Find the equation of the normal to the curve y=(x-2)2/(1-x)2 that is parallel to the line x+4y+7=0 Answered by Harley Weston.
	Five fourths		2001-04-08
		From Linda: Can you have 5/4 of something? Answered by Penny Nom.
	Equivalent fractions		2001-04-08
		From A student: which of the following pairs of fractions are equivalent? questions a-f (a) 1/5 and 6/30 (b) 4/9 and 16/27 (c) 6/10 and 30/50 (d) 15/20 and 48/64 (e) 2/3 and 33/100 (f) 12/32 and 3/16 please show how u got the answer thank you. Answered by Penny Nom.
	Common tangents		2001-04-08
		From Anne: I have been working on this problem for a while but I'm not sure I'm getting the right answer: Find the common tangents of 2y=x2 and 2y=-x2-16 Thanks for the help. :) Answered by Harley Weston`.
	Where do the lines y=2x-4 and y=x-1 intesect?		2001-04-06
		From Bryce: solve the following problem by setting them equal to each other. Solve for x and y. Where do the lines y=2x-4 and y=x-1 intesect? Answered by Penny Nom.
	The unit circle and trigonometry		2001-04-05
		From Ashley: "My teacher wants us to find out what a unit circle is, which I found out, a circle with the radius of 1, but the problem is he wants us to show the relationship between the unit circle and the sine(30,45,60 degrees), cosine(30,45,60 degrees),and tangent ratios(30,45,60 degrees). I need help with this and my teacher will not help us out. Thanks very much ... Answered by Penny Nom.
	Hexominos		2001-04-05
		From Tom: What is a hexomino and how many different shapes are possible? Answered by Harley Weston.
	A combination lock		2001-04-05
		From Ken: What is total number of combinations possible on a combination lock which contains 3 wheels each numbered 0-9? Answered by Penny Nom.
	Percents		2001-04-04
		From Cathy: This isvery embarassing but since math and specifically percentages was my worst subject in school here goes. If I have a figure such as 425 and that amount represents 10% of the total amount how do I find out what the total amount is? Answered by Penny Nom.
	f(x), f(x) + 2, f(x +2)		2001-04-04
		From Monica: Could you explain to me how one should go about graphing functions such as f(x), f(x+2), and so on. Also, how should you explain things such as constants and relationships among functions? Answered by Penny Nom.
	128 percent too high		2001-04-04
		From A student: when pilgrims counted noses, they got a count that was 128 percent too high. if they counted 9120 noses, what was the correct count? Answered by Claude tardif.
	Two integrals		2001-04-03
		From Jim: I'm having trouble with these integrals. Can you help me out? 1)the integral of: x5 arctan x dx 2)the integral of: 2x5 + 9x4 + 19x3 + 13x2 - 5x - 25 ----------------------------------------------- dx x4 + 4x3 + 5x2 Answered by Claude Tardif.
	Approximating 260 divided by 3		2001-04-02
		From Andrew: Choose the letter of the best estimate. 260 divided by 3 a. 60 b. 70 c. 90 d. 100 Answered by Paul Betts.
	(8 + 5)5 = (y + 4)4		2001-04-01
		From Kelley: (8 + 5)5 = (y + 4)4 What is the value of y? Answered by Penny Nom.
	Sigma		2001-03-31
		From A student: What does the Sigma symbol mean in mathematics? Answered by Penny Nom.
	Volume and surface area of a cylinder and a triangular prism		2001-03-31
		From Kevin: I was wondering how do you find the volume and surface area of a cylinder and a triangular prism. Answered by Penny Nom.
	Why K?		2001-03-30
		From Molly: I was wondering why K is used as the dilation constant for transformation geometry? Answered by Chris Fisher.
	Dots on squared paper		2001-03-30
		From Tom: Consider some squared paper with lines 1cm. apart and dots where the lines cross. Place squares whose sides are whole numbers of centimetres on the paper in such a way that the sides of the squares always lie along the lines on the paper. For each square, find (a)the number of points inside the squares; (b)the number of points on the square and (c)the area of the square. How are these quantities related? Answered by Leeanne Boehm and Penny Nom.
	Borrowing from zero		2001-03-30
		From Nikki: Here is the problem: 5,033.56 - 866.20 Now I know this equals 4,167.36 which I figured out on the calculator just to make sure. But when I did it by hand, I kept ending up with 5,167.36, which I knew was impossible. What am I doing wrong?? Answered by Leeanne Boehm and Claude Tardif.
	Stem-and-leaf plot		2001-03-29
		From Kelly: I'm tutoring my 5th grade nephew, and he needs to correct test questions regarding a stem - and - leaf plot. He left his book at school and I'm not familiar with the term. Can you explain it to me so that I can help him? Answered by Penny Nom.
	An emergency response station		2001-03-29
		From Tara: Three cities lying on a straight line want to jointly build an emergency response station. The distance between each town and the station should be as short as possible, so it cannot be built on the line itself, but somewhere east or west. Also, the larger the population of a city, the greater the need to place the station closer to that city. You are to minimize the overall sum of the products of the populations of each city and the square of the distance between that city and the facility. City A is 6 miles from the road's origin, City B is 19 miles away from the origin, and City C is 47 miles from the origin. The populations are 18,000 for City A, 13,000 for City B, and 11,000 for City C. Where should the station be located? Answered by Claude Tardif and Penny Nom.
	Cash advance		2001-03-28
		From A student: dulani has a new credit card. it says: you can get cash advances wherever you are. whenever you want. also if you pay off your balance in full each month for a small transaction fee, the cash is interest free. (see important information on reverse side. On reverese side it says: cash advance transaction fee: $500 or less 2.5%; $500.01 to $1000.00-2%; $1000.01 or more -1.5%; $2.00 minumum. Annual percentage rater for cash advances 19.8%. dulani wants to know what a cash advance will really cost. Analyze the cash advance terms given here. how much would he pay for a $20 cash advance? What about a $450 cash advance? What annual interest rate are these charges equivalent to? choose other amounts. determine cost and annual ratees for these as well. make recommendations to dulani. Answered by Penny Nom.
	The diagonal		2001-03-28
		From Candace: Building measuring 40 feet 3 inches by 50 feet 3inches What is the measurement of the diagonal of the building? What was method of obtainin answer? Answered by Andrei Volodin.
	Solving an equation		2001-03-27
		From Jennifer: How would I solve this equation? 1.6 = 2x/(.1-x) - the equation in parenthesises is raised to the second power. I know you take the square root of both sides, but there is where I get lost. Answered by Leeanne Boehm.
	12 RTV's		2001-03-27
		From Christine: In order to promote the 2000 Census and encourage participation, 12 Road Tour Vehicles(RTV's) set out from 12 locations across the US for a 10 week promotion tour last February. The RTV's reportedly traveled a total combined distance of 97,911 miles. What was the aberage number of miles traveled in a day by each RTV? 2. The 12 RTV's mentioned above traveled a total combined distance equivalent to traveling 12.35 times around the earth at the equator. To the closest mile, what is the radius of the earth? Use 3.14 as your approximation for pi. Answered by Leeanne Boehm.
	A sugar cane crop		2001-03-27
		From A student: a sugar cane farmer harvested only 1/4 of his crop. he sold 2/3 of his harvest to the mill. what fraction of the total crop did he sell. darens recipe for florida fudge calls for 5/8 cup of sugar. if he wants to make only 1/2 of the recipe how much sugar should he use. Answered by Penny Nom.
	Finite non-periodical numbers		2001-03-27
		From Wouter: Is there anyone who knows the official name for decimal finite non-periodical numbers such as 0.4 or 0.25 as opposite of numbers like 0.3333333... or 0.28571428571428...? Answered by Penny Nom.
	Mistie, Tammy, and Jennifer		2001-03-27
		From Renee: Mistie, Tammy, and Jennifer audition for parts in a big-budget remake of Bedtime for Bonzo. On the basis of their past experience and the caliber of competition they face, Mistie has a 40% chance of being hired, Tammy has a 50% chance, and Jennifer has a 30% chance. If exactly two of the three are cast, what is the probability that Mistie was rejected? Answered by Andrei Volodin.
	A box with an interior of 1.25 cubic feet		2001-03-26
		From Gabe: I need a box with an interior of 1.25 cubic feet. I am using 3/4 inch material to make the box. What would the exterior dimensions be in inches? Answered by Harley Weston.
	66:1		2001-03-26
		From A student: I need to know how to convert the ratio 66:1 to a percentage. I can not find an answer any where on-line when the second number is a 1. Answered by Penny Nom.
	Matrices		2001-03-26
		From Peg: What are some applications of matrices, basic trigonometry, and linear systems in the real world? I'm writing and Algebra report about where these topics are used outside of the classroom. Answered by Judi McDonald and Walter Whiteley.
	Two ferry boats		2001-03-25
		From Gil: Two ferry boats leave from opposite shores. One is faster than the other. They meet 720 yards from the nearest shore. They proceed to destination and upon returning they meet 400 yards from the other shore. What is the exact width of the river. Answered by Penny Nom.
	Airflow in windpipes		2001-03-25
		From Ena: The volume of air flowing in windpipes is given by V=kpR4, where k is a constant, p is the pressure difference at each end, R is the radius. The radius will decrease with increased pressure, according to the formula: Ro - R = cp, where Ro is the windpipe radius when p=0 & c is a positive constant. R is restricted such that: 0 < 0.5*Ro < R < Ro, find the factor by which the radius of the windpipe contracts to give maximum flow? Answered by Harley Weston.
	Perimeter of an acre		2001-03-24
		From Liz: What is the perimeter of one acre of land? Answered by Penny Nom.
	Cube roots on a calculator		2001-03-24
		From Will: Hi my name is Will.I have a question about the calculator TI-83 Plus or the use of a scientific calculator. It is about using them to turn a cubed root to a decimal. When using that for a rational and irrational number. Rational numbers is a number that terminates or repeates. A irrational number goes on and on and uses ... (like pie). Like when you type the cube root of 8 it gives you 2, and that is a rational number. The squre root of 2 is 1.41421356... that is irrational. So why is it when you put the cube root of 16 in the calculator it says 2.5198421 that is rational it terminates at the ninth digit and my float is set for the tenth? But why when you do it by hand you get the 2 times the cube root of 2 and that is irrational? Why is that? Answered by Judi McDonald.
	An elliptic tunnel		2001-03-24
		From Janna: A tunnel is built under a river for a road 12m wide with a 2m sidewalk on either side. The top of the tunnel is semi-elliptical. A local bylaw stipulates that there must be a clearance of at least 3.6m at all points on the road. If the smallest possible ellipse is used, find the clearance at the center of the road. Answered by Harley Weston.
	A suspension bridge		2001-03-24
		From Janna: The cables of a suspension bridge hang in a curve which approximates a parabola. The road bed passed through the vertex. If the supporting towers are 720m apart and 60m high, find: a) an equation of the parabola (it's y = 1/2160x2) b)the height of the cables at a point 30m from the vertex. I substituted 30 in for the x value and got 0.42 and the answer is 42. What did I do wrong? Answered by Denis Hanson and Claude Tardif.
	Two problems		2001-03-23
		From James: Casey is a finanical consultant for ABC finance. She earns $456.21 weekly. Her annual group medical coverage costs $1942, of which ABC pays 65%. How much is deducted weekly for medical coverage? and: Eleanor demonstrates microwaves at the national home show. She is paid $7 for each of the first 7 demonstrations and $11 for each demonstration after 7. What is her commission for a day if she makes 12 demonstrations? Answered by Penny Nom.
	A famous landmark		2001-03-23
		From Corinne: A family is traveling due west on a road that passes a famous landmark. At a given time the bearing to the landmark is N 62 degrees W, and after the family travels 5 miles farther the bearing is N 38 degrees W. What is the closest the family will come to the landmark while on the road? Answered by Harley Weston.
	Genealogy		2001-03-22
		From Brian: In considering tracing genealogy the problem of a large and growing number of direct (grandparent) ancestors arose. Since the number of grandparents in any given generation doubles, for a person born in 2000 and assuming 25 year generations, in the year 1000 that person would have over one trillion direct ancestors in that year alone. Since estimates I have read place the total world population in 1000 at 250-300 million, the one trillion figure cannot be correct. I must be missing something in my calculations. Can you help provide the answer? While I am unlikely to be able to trace back to 1000, there is reason to believe 1250 is possible. Even in that year there would exist over one billion direct ancestors. That is certainly rather daunting and unlikely to be achieved if correct. Answered by Penny Nom.
	Camille Jordan		2001-03-22
		From Missy: PLEASE SEND ME INFORMATION ON CAMILLE JORDAN AND HIS WORK IN ABSTRACT ALGEBRA Answered by Rick Seaman.
	Factoring		2001-03-22
		From Kaleena: Factor this equation: 5x7-10x5+4x3-8x Answered by Harley Weston.
	Why exactly can't you divide fractions?		2001-03-22
		From Dennis: Why exactly can't you divide fractions? Answered by Penny Nom.
	The repetend in repeating decimals		2001-03-21
		From Sharon: What is the name for the bar over the repetend in repeating decimals? Also, what is the name of the long division "house"? Answered by Penny Nom.
	A bargin with the devil		2001-03-21
		From DJ: There once was a boy who spent all his time dreaming about getting rich. " I would do anything to be rich". The devil, hearing this, appeared before the boy and offered to make him rich. "See that bridge?" said the devil. Just walk across and I will double your money you have now. In fact, each time you cross I will double your money. There is just one thing you must give me $24 after each crossing. The boy agreed. He crossed the bridge, stopped to count his money and, and sure enough, it had doubled. He paid the devil $24 and crossed again. Again his money doubled. He paid another $24 and crossed a third time. Again his money had doubled, but this time there was only $24 left which he had to pay the devil so he was left with nothing. The devil laughed and vanished. How much money did the boy start with? Answered by Penny Nom.
	Timing with hour glasses		2001-03-20
		From Nathan: How can a chef use an 11 minute hour glass and a seven minute hour glass to time a vegtable that needs to be steamed for 15 minutes. Answered by Leeanne Boehm.
	Radicals		2001-03-18
		From Nikki: 3) squareroot of x2 + 10x + 25 4) sixthroot of (m + 4)6 5) cuberoot of -64r6w15 . . . . Answered by Penny Nom.
	Systems of equations		2001-03-16
		From joy: How do u solve problems using systems of equations? ~ finding x and y~ ex: 26 = 3x - 2y 42 = 4x + y Answered by Penny Nom.
	How can you prove a quadrilateral to be a parallelogram?		2001-03-16
		From Joy: How can you prove a quadrilateral to be a parallelogram? Answered by Walter Whiteley.
	Probability and a three digit number		2001-03-15
		From Glenn: A THREE DIGIT NUMBER IS SELECTED AT RANDOM. WHAT IS THE PROBABILITY THAT NON OF THE THREE DIGITS ARE PRIME. Answered by Harley Weston.
	Names of the polygons		2001-03-15
		From Sami: I was asked to find out what the names for different polygons were. The only two I cannot find are the names for a polygon with 30 sides and a polygon with 40 sides. I would really appreciate it if you could help me. Thank you very much. Answered by Harley Weston.
	The bond angles of a tetrahedral polygon		2001-03-14
		From Nishi: how do i prove (a simply as possible) why the bond angles of a tetrahedral polygon are 109.5 degrees? *i already have two explanations that i don't understand. one is about "theory of dot products" and "vectors" and a hook-like symbol w/ a cosine, and the other has an incomprhensible diagram w/ difficult notation- PLEASE BE SIMPLE! thanks sooo much Answered by Harley Weston.
	A jogger		2001-03-12
		From Bill: At time t=0 a jogger is running at a velocity of 300 meters per minute. The jogger is slowing down with a negative acceleration that is directly propotional to time t. This brings the jogger to a stop in 10 minutes. a) write an expression for the velocity of the jogger at time t. b) what is the total distance traveled by the jogger in that 10-minute interval. Answered by Harley Weston.
	Quadratic equations		2001-03-11
		From Philip: I am a student in the UK and i am in secondary school and i am doing my GCSE next year. here are my questions: solve the following equations correct to 2 decimal each time. [1] 2xsquared + 5x = 1 [2] 3xsquared(2x+1)=1 [3] xsquared + 7x + 2 = 2x + 4 [4] 5xsquared - 3x = xsquared + 4 Answered by Penny Nom.
	Math Puzzle		2001-03-10
		From Vanessa: I have a math puzzle. I have been working on it for over 2 weeks. Here it is: use the numbers 1-25 each only once. The rows across are an equation and the columns down are an equation. There are 25 boxes. You have to use the order of operation x and / first then = and -. Some of the answers are -numbers. . . . Answered by Claude Tardif.
	Two locus problems		2001-03-08
		From Janna: A point P moves such that it is always equidistant from the point G(2,5) and the line defined by y=3. Find the equation of the locus. I got as far as the equation: 3y2 -4y = -x2 + 4x - 16 and didn't know what to do from there. Of, course that whole equation could be wrong. Question 2: P is always twice as far from A(8,0) as it is from B(2,0). Find the equation of the locus. Once again, I got as far as y2 = -x2 -8x -56, and got stuck. Answered by Harley Weston.
	The angle of elevation		2001-03-08
		From Jeffrey: At a Certain time, a vertical pole 3m tall cast a 4m shadow. What is the angle of elevation of the sun? Answered by Harley Weston.
	4160		2001-03-07
		From Jessica: The product of two consecutive page numbers in this book is 4160. What are the page numbers? Answered by Penny Nom.
	problem of the week		2001-03-06
		From Peggy Allan: My son has been challenged with "the problem of the week" and I am unable to assist him in finding a reasonable solution. Problem 1, Julio needs to draw a line segment 15cm long. He does not have a ruler. He does have some sheets of letter size paper 28 X 21.5 cm. Describe how Julio can use the paper to measur 15 cm. Answered by Claude Tardif.
	The substitution method		2001-03-05
		From A student: Solve each system of equations by the substitution method. Show your work. y = 8 7x = 1 - y y = x - 1 4x - y = 19 Answered by Penny Nom.
	Powers		2001-03-04
		From A student: Hey, can you show me how you do .. (2xy)to the 3rd power (x) to the 2nd power? Answered by Penny Nom.
	Coins and monomials		2001-03-04
		From A student: Tokola has 5 coins with a total value of $1.05. He canot make change for a dollar, 5 cents, 10 cents, 25 cent, or 50 cents. What 5 coins does he have? and Determine whether 6c-d is a monmial. Explain why or why not. Answered by Penny Nom.
	Arc of a sphere		2001-03-04
		From Some students: My friends and i have a geometry project and we cannot seem to figure out how to find the arc of a sphere. Answered by Harley Weston.
	What is the value of n?		2001-03-03
		From Adam: When I add n to 7 and then divide my answer by 4,I get 5. What is the value of n? Answered by Penny Nom.
	Spins of a roulette wheel		2001-03-02
		From Bob: Here's a problem I'm working on myself.....If you look at six consecutive spins of a roulette wheel, how many combinations of red and black are possible? I.E. BRRBRB, BBBBBR, BBRRRB......ETC..... Answered by Claude Tardif.
	How tall is the tree?		2001-03-02
		From Ronda: a tree's shadow is 42 ft. long. There is a stop sign that is right next to it and it is 18 ft. tall and it's shadow is 12 ft. long. How tall is the tree? Answered by Penny Nom.
	Is there an odd and even function?		2001-03-02
		From Saima: Is there a function that is both even and odd at the same time? In other words, is there a function that can pass the y-axis, x-axis, and origin symmetry test? Answered by Claude Tardif and Penny Nom.
	P vs NP problem		2001-03-01
		From Roy: What math journals would publish a proposed solution to the P vs NP problem when the work has been done by an amateur mathematician who has no degree in math? Answered by Claude Tardif.
	Converting percents to decimals		2001-03-01
		From Elliot: My math question is about Converting Percents to Decimals, here it is- Convert 37 1/2 = ? Answered by Penny Nom.
	The price of a carpet		2001-03-01
		From Amber: i have to calculate the square footage of carpet for me room and im not quite sure how to do that. the carpet is $2.08 per sq. ft. and my room is 12x11ft. Answered by Penny Nom.
	Solve for the variable		2001-02-28
		From Ashley: I've got 2 questions. We (my dad and I) can not figure them out. please help me. 21 = 9 - 2 (4a + 2) and I am supposed to find out what the variable is. 2/3 n + 3/8 n = 15/16 (those are fractions). Again, I need to find out what the variable is. Answered by Penny Nom.
	Fibonacci		2001-02-28
		From Shona: We have been doing pattern finding with him, talking to a friend he mentioned the "Fibbinacci Series" ?, while I have tried to find a bit about it, how works etc.. what it is about, I have not really found out much, what I have I feel is way beyond him, but am still curious to know the basics of it myself. Would you be able to tell me in laymans language. Would be very much appreciated. Answered by Claude Tardif.
	Three sheep		2001-02-28
		From A student: A farm sold three sheep. the weight of the three sheep combine wae 152 lbs. The smallest sheep weighted 7 lbs less than the middle size sheep. The largest sheep weighted three times the smallest sheep. what is the weight of each sheep? Answered by Penny Nom.
	T-numbers an T-totals		2001-02-27
		From Mr. M. Wiseman: Investigate the relationship between the T-total and the T-number. Answered by Penny Nom.
	Lotto 6-49		2001-02-27
		From A student: I am a secondary student and I was wondering if there was a better way to find out how many combinations and what they are in the lotto 6/49 than writing them out on a piece of paper. Any help you can provide me with would be greatly appreciated. Answered by Penny Mon.
	The n-th place of pi		2001-02-27
		From Andrew: I have always wondered; is it possible to find the value of an irrational number, such as (phi) at it's nth decimal place??? You would plug the decimal place into the formula and the value would be given at the specified decimal place. When we look at the expression { (sqr 5 + 1)/2 } we are in a sense visualising the number in it's entirety, so the formula may include elements of the above expression in some form. Answered by Claude Tardif.
	Domain and Range and Zeros		2001-02-27
		From Beth: 1. f(x)=15-2x-x2 2. g(t)=square root of 4-t2 3. y=t-3/t2-t-6 Answered by Penny Nom.
	MIRA		2001-02-27
		From Constantinos: What is a "mira," and how is it used in terms of topology (in geometry)? If you can answer my question, and even refer me to online or other resources to find out more, I would greatly appreciate it. Answered by Walter Whiteley.
	Shape names		2001-02-26
		From Paul: I have been asked to give names of shapes from A to Z . I can only find 14 shapes can you help..... I'm missing letters b, g, j, l, m, n, u, v, w, x, y, z. Answered by Harley Weston.
	Solve for two variables		2001-02-25
		From A student: How do I solve for %1 and %2 in the following formula when T1, T2 and T3 are known? %1 and %2 are ratios of the same element, therefore %1 + %2 = 100% (%1 x T1) + (%2 x T2) = T3 Answered by Penny Nom.
	Shape, symmetry, measurement and space		2001-02-24
		From Marilyn: I have to write in detail about how young children learn about shape, symmetry, measurement and space. It is not activities I need it is how the children learn. How/why their brain takes it all in Answered by Walter Whiteley.
	Solving Equations		2001-02-23
		From Stephanie: Do you know who came up with solving equations? Do you have any web-sites that can give me good information on solving equations? Do you know any history on solving equations? Do you know what solving equations is used for? And finally............Sorry about all of the questions :) Has the form of solving equations changed from the time it came out to now? Answered by Juci McDonald.
	What is my name?		2001-02-23
		From Julia: My perimeter is 12 cm. My sides are all equal. The sum of half my sides is equal to 6 cm. How many sides do I have? What is my name? Answered by Penny Nom.
	Difference of Squares		2001-02-22
		From Bruno-Pierre: I noticed the other day that if you substract two consecutive squared positive numbers, you end up with the same result as if you add up the two numbers. Ex. 5 and 6 (2 consecutive positive numbers) 52 = 25 62 = 36 36 - 25 = 11 (Substraction of the squared numbers) 5 + 6 = 11 (Sum of the numbers) A more algebric view: a2 - b2 = a + b where a and b are consecutive positive positive numbers. (b = a + 1) I wondered if this rule had a name, and who discovered it. Answered by Penny Nom.
	The domain of the derivative		2001-02-22
		From Wayne: I know that the domain of f'(x) is a subset of the domain of f(x). Is it necessarily true that the subset will have at most one less element than the domain of the original function? Answered by Harley Wesston.
	Find the two numbers		2001-02-21
		From A grade 6 student: Find the two numbers: 5 is a common factor; 100 is a common multiple; neither number is a mulitple of the other; both are even. Answered by Penny Nom.
	Mr. Moser's roof		2001-02-21
		From Michelle: Mr. Moser is planning to replace the roof of his home. He needs to order a pack of shingles. Each pack covers 100 sq. ft. of roof. Without a ladder, Mr. Moser can not climb to the roof to measure it. Instead, he measures his attic and finds it to be 40 ft. long, 24 ft. wide, and 5 ft. high at the peak of the roof which is in the center of the house. Although the roof is even with the side walls, he estimates the roof line continues 1.5 ft. beyond the front and back walls. How many full packs of shingles should Mr. Moser order to cover his roof? Answered by Penny Nom.
	Winning percentages		2001-02-21
		From Mike: TEAM A WINS 55% OF GAMES PLAYED TEAM B WINS 40% OF GAMES PLAYED AGAINST THE SAME OPPONENTS WHAT WINNING PERCENTAGE SHOULD BE EXPECTED WHEN TEAM A PLAYS TEAM B (NEUTRAL SITE)? Answered by Harley Weston.
	Congruence and symmetry		2001-02-21
		From Chris: My name is Chris and I am a second-grade teacher. I would like to know what the difference is between congruent and symmetry, and how do I explain this to my class? I know that congruent means the same, and symmetry is two identical sides. Is there a difference between the two? I know there must be, but I don't know what or how to explain these two terms. Answered by Walter Whiteley.
	Faces		2001-02-21
		From Sandy: How many faces are there on a sphere? What are the faces of a cone? What is the definition of a "face" of a 3D object? Answered by Walter Whiteley.
	Math game 24		2001-02-21
		From Kristi: We have a game we play in math class called 24 game. In it each card has 4 numbers on it. Each number can only be used once, in any order, using multiplication, subtraction, division, or addition. We are stuck on one and wondered if you could help. The four numbers are: 3, 3, 5, 7. And they must equal 24. Any clues? Answered by Claude Tardif.
	The law of cosines in the real world		2001-02-21
		From Hope: Do you have any examles and/or labs that show how the law of cosines is used in the real world? Answered by Harley Weston.
	Undecagon		2001-02-21
		From Karen: I need to know what kind of a polygon an undecagon is and how many sides it has. This is a problem in my math book. Answered by Penny Nom and Michael Tsatsomeros.
	Ratios		2001-02-20
		From Louise: there are 3 people and they decide to share their tips (working in a restaurant) ann gets £180 tony £130 peter £90 total amount is £36 what share should they get. Answered by Penny Nom.
	Expanding determinants using minors		2001-02-20
		From A student: Question: 1) Determinants by expansion by minors. i) | 1 2 1 2 1 | | 1 0 0 1 0 | | 0 1 1 0 1 | | 1 1 2 2 1 | | 0 1 1 0 2 | Answered by Harley Weston.
	A remainder of 1		2001-02-20
		From A student: what is the smallest positive integer which has a remainder of one when divided by 2,3,4,5 and 6 Answered by Penny Nom.
	A pole next to a building		2001-02-20
		From Robert L. Haun: A pole 100 feet tall is erected next to a building 10' X 10' X 10' . Object is to cut off the pole so the upper end remains touching the part cut off, while the cut-off portion touches the cutoff point, the edge of the building and the ground. Note assume the pole is touching the building and is "very thin" What is/are the cutoff points? Answered by Penny Nom.
	Cubic feet		2001-02-20
		From Frances: I'm trying to calculate cubic feet from the dimensions of a machine given in inches. Width = 32" Height = 79.5" Length = 91.5" Weight = 3920 lbs Please help? Obviously I've been away from school too long!! Answered by Penny Nom.
	Law of cosines		2001-02-20
		From Emily: I missed a few days of class and I can't figure out how to solve Law of Cosines problems. I have the notes and formulas but I can't figure out how to do the math involved to answer the problems. I am also getting confused about how to use degrees and seconds in the Law of Sine and Cosine. I can't seem to get the correct answers and I don't really know how to solve them and enter them into my TI 86. Answered by Harley Weston.
	Difference of squares		2001-02-20
		From Janna: Hi! I was just wondering how you would factor x2 - 9y2. Answered by Harley Weston.
	Delivering firwood		2001-02-20
		From Jackie: Two college students earn extra money on weekends by delivering firwood in thier pickup truck. They have found that they can sell x cords per weekend at a price of p dollars per cord, where x=75-3/5 p. The students buy the firewood from a supplier who charges them C dollars for x cords to the equation C=500+15 x+1/5 x2. a) find a function f such that P=f(p), where P dollars is the profit per weekend for the students if they charge p dollars per cord. b)find the profit P dollars if p=$95 Answered by Penny Nom.
	g(g+5)=0		2001-02-20
		From Jenna: g(g + 5) = 0 Answered by Penny Nom.
	The area of platts		2001-02-20
		From Steve: I have to calculate the areas of different "platts" of land from a map, and the only thing I have are the four side measures. There are some cases where no sides are parallel, no lengths the same, and no angles are given, and I was wondering how to calculate the area of such figures. I've attached a rough sketch of a typical platt's shape. Answered by Walter Whiteley.
	Dividing polynomials		2001-02-19
		From Janna: I have two questions involving dividing polynomials by polynomials. Here's the first one: Two factors of 12a4 -39a2 + 8a - 8a3 + 12 are a - 2 and 2a + 1. Find the other factors. The other question I'm stuck on is: When 10x3 + mx2 - x + 10 is divided by 5x-3, the quotient is 2x2 + nx - 2 and the remainder is 4. Find the values of m and n. Answered by Penny Nom.
	Adding functions		2001-02-19
		From Jackie: f(x) = x2 + 1; g(x) = x2 - 1 find a) ((f+g) of h)) (x) b) ((f-g) of h)) (x) c) ((f of h) - (g of h)) (x) Answered by Penny Nom.
	Working on commission		2001-02-17
		From Jay: Ron the realtor is offered a job directly out of real-estate school. He has a choice as to which way he will receive his salary the first year. Salary Plan 1: He would receive a base pay of $2000 per month plus a 3% commission on each sale. Salary Plan 2: No base pay but a 6% commission on each sale. Write an equation to determine when it would be better to switch from the first plan to the second plan. Give a one- or two-sentence answer that includes Ron`s sales in a month. Round to the nearest dollar, if necessary. Answered by Leeanne Boehm and Penny Nom.
	Some fractions		2001-02-17
		From Lady Bird: Mr. Bob has 3/4 of a bottle of medicine left. He takes the medicine three times a day. Each dose is 1/16 of the bottle. How many days will it take for Mr. Bob to finish the bottle? My friend gave me a problem to solve and it is so hard. Can you help me solve it? Here it is: If g- 4.8 = 9.66 and e-1/3 = 1/8, what is the sum of g and e? Mariko's mother used ribbon to wrap 3 birthday gifts. She had 3 ribbons and each was 72 inches long. She used 8/9 of the first ribbon, 2/3 of the second ribbon, and 5/6 of the the third ribbon. How many feet did she use? Answered by Leeanne Boehm and Penny Nom.
	Angles in a polygon		2001-02-17
		From Joan: How many sides does a polygon have if its smallest interior angle is 120 degrees and each sucessive angle is 5 degrees greater than the predecessor? Answered by Penny Nom.
	Percentage increase		2001-02-17
		From Bob: If sales for jan 2001 are 154 vs 105 for 2000 - the increase total presented to my office is +46% - how does that compute. Please give me the equation. Answered by Penny Nom.
	Differentiation of y = x n		2001-02-17
		From Jashan: i am studying differentation at the moment i have drawn some graphs such as y=x 2. i have found the formula for the gradient of this curve, this being 2x obtained by using differentation, but i need to know the general case for the formula where y=xn in order for me to understand this topic more throughly, i would also like to know how u derived this general formula Answered by Harley Weston.
	A four digit number		2001-02-17
		From Dean: Need to find a 4 digit number that can be divided by 2, 3, 4, 5, 6, 7, 8, 9, and will always have a remainder of 1 in the answer. Answered by Penny Nom.
	Triakis		2001-02-17
		From Anne Grant: I am a grade 8 teacher and have come across the term "Triakis" used with Tetrahedron, octahedron, and hexahedron. What does this term refer to, and what's the difference between a triakis polyhedron and one that is not? I'd also like to know what is meant by the term antiprism, as opposed to prism. Answered by Penny Nom.
	Symmetry		2001-02-15
		From Sonam: What is symmetry? Who invented symmetry? what are the different kinds of symmetry? Answered by Penny Nom.
	A quartic equation		2001-02-15
		From George: Let P(x) = x4 + ax3 + bx2 + cx + d. The graph of y = P(x) is symmetric with respect to the y-axis, has a relative max. at (0,1) and has an absolute min. at (q, -3) a) determine the values for a, b c, and d using these values, write an equation for P(x) b) find all possible values for q. Answered by Harley Weston.
	A four dimensional object		2001-02-14
		From A student: Can you give me some examples of a four dimensional object you can find around your house? Answered by Harley Weston.
	Linear equations		2001-02-13
		From Jamie: I have a question how do you do linear equation? Answered by Penny Nom.
	Rewrite as an addition problem and Simplify		2001-02-13
		From A student: On my homework sheet it says "Rewrite as an addition problem and Simplify" and the gives this problem "16 - 120 =" how do i do that problem? Answered by Penny Nom.
	Books and cars		2001-02-13
		From Aquilya: A pile of books is 96.08cm. If each book is 0.8cm thick. How many books are in th pile? 2. A car travels 9.84km on 0.6 litres of petrol. How far will the car travel on 3.7 litres of petrol? Answered by Penny Nom.
	L - R		2001-02-12
		From A student: If L = (a-b)-c and R=a- ( b-c), then L-R = ??? Answered by Penny Nom.
	An order relation		2001-02-12
		From Amy: What is an order relation? Answered by Claude Tardif.
	Two inequalities		2001-02-12
		From A student: If 3 Answered by Leeanne Boehm.
	Part of a part		2001-02-11
		From Katie: Hello! I was looking at your Fraction questions and since i am pursuing to be an elementry school teacher i feel i don't understand one of your responses. How would you explain this to an elem, midd, and high school student. Even me myself-in college really does not understand. The question was: When you multiply two positive fractions less than 1, how does the answer compare to the size of the fraction? Why? Answered by Penny Nom.
	A merchant from Pisa		2001-02-11
		From A student: A merchand doing business is Lucca doubled his money there and spent 12 denarii. On leaving, he went to Florence, where he also doubled his mone and spent 12 denarii. Returning home to Pisa, he there doubled his money and again spent 12 denarii, nothing remaining. How much did he have in the beginning? Answered by Claude Tardif.
	Chris' cards		2001-02-11
		From A student: Chris gave Jane x cards. He gave Bety one card more than he gave Jane and he gave Paul two cards fewer than he gave Betty. In terms of x, how many cards did Chris give Bety, Jane, and Paul together? Answered by Penny Nom.
	percent		2001-02-11
		From A student: what is 1.5% of 20386.01? Answered by Penny Nom.
	Multiplying one and two digit numbers		2001-02-11
		From Marty: When multiplying do you put the number you are multiplying by on the top or the bottom. Example if you are multiplying by 6's would you write the problem 6 x 2 or 2 x 6 Maybe it just doesn't matter. But when you get to double digits, the double digit always goes on the top? Answered by Penny Nom.
	Lucky dip		2001-02-09
		From Andrew: I buy 8 lucky dip (random number) panels, each panel has 6 numbers chosen at random from 49. I never seem to cover more than 32 different numbers on average, over the total 48 numbers chosen, which seems low? How can I calculate the probability of 32 different numbers or 33 diferent numbers? Answered by Claude Tardif.
	A dog and a rabbit		2001-02-09
		From Josh: 1. A dog and a rabbit are 160 meters a part for every 9 meters that the dog runs , the rabbit jumps 7 meters. How many meters must the dog run in order to vertake the rabbit??? 2. A cars odometer reads 15951 KM. Find the least number of kilomaters to travel until the palindromic number appears??? Answered by Leeanne Boehm.
	What is wrong with these probelms?		2001-02-09
		From Cindy: Hi, I am a planning on becomming a teacher and i am asked to find out what is wrong with these probelms and how i would go about showing a student what is wrong with them!! Error in patterns: 13/35=1/5; 27/73=2/3; 16/64=1/4 4/5+2/3=6/8; 2/5+3/4=5/9; 7/8+1/3=8/11 2/3*3=6/9; 1/4*6=6/24; 4/5*2=8/10 Answered by Leeanne Boehm and Penny Nom.
	The odds of winning		2001-02-09
		From Anna: The odds of winning in a game are 3 out of 10. How many times would one have to play the game in order to be sure they would win? Answered by Leeanne Boehm.
	Kinds of lines		2001-02-09
		From Robyn: What are the different kinds/types of lines? Answered by Leeanne Boehm.
	An irregular polygon		2001-02-09
		From Jason: I have a 5 sided irregular polygon I am trying to figure out the area of. There are no right angles in the polygon as far as I can tell. I do not know any angles. Answered by Chris Fisher.
	Partitioning of an arbitrary line segment		2001-02-08
		From David: Did Euclid's Geometry include a construction for the regular partitioning of an arbitrary line segment? Answered by Chris Fisher.
	Bicycles and phone calls		2001-02-08
		From Sarah: A bicycle has a diameter of 66 centimeters. How many times must the tire rotate to travel 1 kilometer?explain answer. Becky want to make a long distance call to her friend Sarah from a pay telephone.She has $5.00 in change.The call costs $0.90 for the first three minutes and $0.24 for each additional minute.How long can Becky talk to Sarah? Answered by Leeanne Boehm.
	Buckets of golf balls		2001-02-08
		From A student: A bucket containing 40 golf balls weighs 135 ounces. The same bucket with 20 golf balls weighs 75 ounces. What is the weight of the bucket? Answered by Claude Tardif.
	Find an exprression for f(x)		2001-02-07
		From A 12th grade AP Calc student: Let f be the function defined for all x > -5 and having the following properties. Find an expression for f(x). i) f ''(x) = 1/ (x+5)1/3 for all x in the domain of f ii) the line tangent to the graph of f at (4,2) has an angle of inclination of 45 degress. Answered by Harley Weston.
	The "goesinta" box		2001-02-07
		From Bridget: We are looking for the "proper" name of the "box" that is drawn around the dividend on a division problem: ___ 3)12 It has always been a family joke to call it the "goesinta" box, but a search of several reference sources hasn't yielded an answer -- This is a question of curiosity rather than a question for homework. Answered by Claude Tardif.
	(-2b+3)(-b-1)		2001-02-06
		From Melissa: Alright, lets say you are multiplying (-2b+3)(-b-1) and you are using "FOIL" first you would get : 2b2+2b-3b-3 then you add like-terms. when multiplying,if the bases are the same, add the exponents...does the same thing apply when you are adding the results of the multiplication even though it's addition? would the answer be 2b3-3b-3 or would it be 2b2-b-3? Answered by Penny Nom.
	23 + 17 * 2 / 8 + 11 = 13		2001-02-02
		From David: My child is working through basic operations, and gave this problem: 23 + 17 * 2 / 8 + 11 = 13 The teacher wants the parenthesis to be put in the right places to come up with 13. Answered by Claude Tardif.
	Which fraction is greater?		2001-02-01
		From Carol: Hello My name is Carol I am a student teacher! I am asked to aproach these students on their problems. I am unsure of how to explain to them that these are wrong. Can you help? Thanks. Iris claims that if we have two positive rational numbers, the one with the greatest numerator is the greatest. Shirly claim that if we have two positive rational numbers, the one with the greatest denominator is the least. Thanks! Answered by Claude Tardif.
	Gross markup		2001-02-01
		From Chris: Total GM Sell $2650 40% $4,416.67 GM is Gross Margin? do you have any meanings for this like Gross markup etc? Can you show me the working of how you get the 2650 to sell at 4416.67 Answered by Penny Nom.
	Finding roots		2001-02-01
		From A student: My math problem is right now we are working on roots. I don't quite understand how to find the answer to the problems, i was wondering what is the easiest, and fastest way to find the answers to roots? Answered by Penny Nom and Claude Tardif.
	The solutions of a quadratic		2001-01-30
		From A student: Show that the product of the solutions of ax2 + bx + c = 0 is c/a. For each equation under the given condition, (a) find k and (b) find the other solution. kx2 - 2x + k = 0; one solution is -3 Answered by Penny Nom.
	Why is 0! = 1?		2001-01-30
		From Diane: Every math book always claims that 1!=1 and 0!=1 are givens, and that we should just memorize it. i understand the 1! part, but where is the basis for claiming that 0!=1???? Answered by Walter Whiteley.
	Unscramble these words		2001-01-30
		From Myosha: Hi my name is Myosha. I would be part of the secondary(6~9) class. I need you to unscramble these words & define them for me. edicnreeff rtgeare itfrnoca lmicdae sdvioini imrretepe Answered by Claude Tardif.
	Two number theory questions		2001-01-30
		From Richie: i have two questions and they are: the product of three consecutive prime numbers is 7429. Find the product of the smallest and largest of these three integers. the least common multiple of two relatively prime positive integers, a and b, is 144. if a (a>or=2) is as small as possible, compute the value of b. Answered by Penny Nom.
	Subsets of the natural numbers		2001-01-30
		From Christina: How do I explain why the set of natural numbers (N) cannot be equivalent to one of its finite subsets? Answered by Penny Nom.
	Fractions of fractions		2001-01-30
		From Katie: When you multiply two positive fractions less than 1, how does the answer compare to the size of the fraction? Why? Answered by Penny Nom.
	Crossing the dessert		2001-01-29
		From Zach: An Explorer needed to make a 5 day trip across a dessert. Each man with him could carry exactly 3 days food and water. For one man how many men will it take to cross the dessert? Answered by Claude Tardif.
	Geometric and arithmetic sequences		2001-01-26
		From Garry: what are the equations for geometric and arithmetic sequences? also, what are the equations for finding the sums of those series? Answered by Leeanne Boehm and Penny Nom.
	Processing speed		2001-01-26
		From Zac: A COMPUTOR IS ADVERTISED AS HAVING A PROCESSING SPEED OF 11 MILLION INSTRUCTIONS PER SECOND. ON THE AVERAGE, HOW LONG DOSE IT TAKE TO PROCESS ONE INSTRUCTION AT SUCH A SPEED? Answered by Leeanne Boehm.
	Equilateral		2001-01-25
		From A student: I AM 9 YEARS OLD AND I HAVE HOMEWORK. I WOULD LIKE TO KNOW IF THERE IS SUCH A THING AS A EQUILATERAL SQUARE. Answered by Penny Nom.
	Rotation		2001-01-25
		From A student: If I have a rectangle 2inches long and 4 inches wide and I rotate the rectangle 45 degrees will the length still be 2 inches? Answered by Penny Nom.
	Conversions		2001-01-24
		From Tanya: I have 2 questions covert 628 kilometers to miles.(round off your answer to two decimal places.) a new clerk in your office is to earn $200 per week. If she works 30.5 hours each week, what is her hourly rate? (round off your answer to the nearest hundreth, that is, to the nearest cent.) Answered by Penny Nom.
	Building a circular silo		2001-01-24
		From Natasha: We wish to build a circular silo with internal diameter 10 feet. How much concrete will we need to pour the foundation, if we only need a 1 foot wide and 1 foot deep ring on which the silo walls will sit? Assume the 4 inch thick silo wall rests on the middle of the ring. Answered by Penny Nom.
	Factoring		2001-01-24
		From Danielle: 4(x+1)2+y(x+1) Answered by Penny Nom.
	Factoring a trinomial		2001-01-24
		From Kyle: I am an eighth grade student.I can not figure out the following problem. 4x2 + 2x - 20 Answered by Leeanne Boehm.
	14, with 5 ODD numbers		2001-01-23
		From Robyn Ernst: How can you get 14, with 5 ODD numbers? Answered by Claude Tardif.
	Cincinnati to Winston-Salem		2001-01-23
		From Belinda: Joan Bedney travels from Cincinnati to Winston-Salem at an average rate of 40 miles per hour and returns at an average rate of 60 miles per hour. What is her average speed for the trip? Answered by Leeanne Boehm and Claude Tardif.
	1 + 1 = 1		2001-01-23
		From Stephanie: My friend has this as a bonus question the other day and I want to figure it out. I don't know how 1+1 in any form could equal 1. Please let me know how you come about geting that. Answered by Claude Tardif.
	7x6 by doubling		2001-01-23
		From A student: Can you think of a way to use doubling to multiply 6x7? Answered by Allen Herman.
	What number from 1 to 25 has the most factors?		2001-01-23
		From John: What number from 1 to 25 has the most factors? Answered by Penny Nom.
	0,2,3,6,7,1,9,4,5,8		2001-01-23
		From Tami: What is the sequence of the numbers 0,2,3,6,7,1,9,4,5,8 Answered by Claude Tardif.
	Some algebra		2001-01-23
		From Thomas: If a is 4 more than the quotient of b and 3, and if b=2, then what is the value of a? Answered by Penny Nom.
	The sum of the angles in a polygon		2001-01-23
		From A student: What is the sum of the measures (interior angles) in an octagon ... heptagon ... decagon. Answered by Penny Nom.
	The hypotenuse of a right triangle		2001-01-22
		From Phillipe: How do you find the hypotenuse of a right triangle? Answered by Penny Nom.
	Conditional probabiity		2001-01-22
		From Wallace Yang: A pair of six-sided fair dice is thrown. Find the probability that the sum is 10 or greater if it is given that a 5 appears on at least one of the dice. Answered by Penny Nom and Claude Tardif.
	Square feet and cubic feet		2001-01-21
		From Jenny: How do I convert square feet to cubic feet? If I have 2000 square feet then how many cubic feet do I have? Answered by Harley Weston.
	25% mark up		2001-01-20
		From Vivian: If it costs me $100.00 to manufacture an item and I want to sell it at a 25% mark up, why do I get different answers when I perform the operation the following ways? 1. $100.00 x 25% = $25.00 $100.00 + $25.00 - $125.00 2. $100.00 / .75 = $133.334 Should these two not be equal? Answered by Penny Nom and Claude Tardif.
	A prism		2001-01-18
		From Nigel Ayling: What is the mathematical definition of a prism, I am confused by the following definitions as they appear to be contradicto... Answered by Walter Whiteley.
	Proportionality: direct and indirect		2001-01-18
		From Nancy Ellis: What is the difference between directly proportional and indirectly proportional? Answered by Leeanne Boehm.
	More repeating decimals		2001-01-17
		From Alan: I am neither a math teacher nor a student, but I hope you will consider my question anyway. I recently was discussing repeated decimals with a friend, and went on the web to find out more about a pattern was looking for years ago. In doing so I came upon your correspondence on repeating decimals. . . . Answered by Chris Fisher and Penny Nom.
	Greatest common factor		2001-01-17
		From A teacher: I'm a teacher at a local Middle School and I would like the answers for the following questions. What is the greatest common factor for.. 546 and 780 156 and 732 . . . Answered by Leeanne Boehm and Penny Nom.
	Motivators		2001-01-16
		From Michelle Stapley: Do you know of any (or where I can find) student motivators for math at the secondary level? Basically any way I can motivate my students to WANT to learn math. Answered by Penny Nom.
	A problem with distance		2001-01-16
		From A student: For what values of a is the distance between P(a, 3) and Q(5, 2a) greater than the square root of 26. Answered by Penny Nom.
	Some complex problems		2001-01-15
		From Nick: I am having enormous difficulty with one question in my maths homework. The question is shown below. If anybody out there can find the answers and show the workings and help me to understand. Answered by Harley Weston.
	Polynomials and exponents		2001-01-15
		From A student: I am duing a project in math on polynomials and exponents. I need a real life usage of polynomials and exponents for my project. Answered by Penny Nom.
	The path of a cannonball		2001-01-15
		From A student: Artillerymen on a hillside are trying to hit a target behind a mountain on the other side of a river. Their cannon is at (x, y) = (3, 250) where x is in kilometers and y is in meters. The target is at (x, y) = (-2, 50). In order to avoid hitting the mountain on the other side of the river, the projectile from the cannon must go through the point (x, y) = (-1, 410). Write the equation for the problem. Answered by Penny Nom.
	Some terms in a sequence		2001-01-15
		From jamie: Please help as soon as possible! i am stuck with some terms in a sequence. the terms are 1st term=1, 2nd term=10, 3rd term=35, 4th term=84, 5th term=165, 6th term=286. can anyone tell me the formula for the nth term? n is term number Answered by Sukanta Pati.
	Arranging some numbers		2001-01-14
		From Denise: Arrange the following numerals in two groups of four each so that each group will add to give the same sum. 1 2 3 4 5 7 8 9 Answered by Penny Nom anf Claude Tardif.
	Exponents		2001-01-14
		From A student: I am wondering if a number raised to the second power is "squared" and a number raised to the third power is "cubed" is there a name for any number raised to any other power. Answered by Harley Weston.
	Vitamins A and B		2001-01-14
		From Sara: A diet is to include at least 140 mg of Vitamin A and at least 145 mg of vitamin B. these requirements are to be obtained from two types of food. type X contains 10 mg of vitamin A and 20 mg of vitamin B per pound. Type Y contains 30 mg of vitamin A and 15 mg of vitamin B per pound. if type X food costs $12 and Type Y $8 per pound, how many pounds of each type of food should be purchased to satisfy the requirements at the minimum cost? Answered by Claude Tardif and Harley Weston.
	Compression by a factor of ?		2001-01-12
		From Wayne: Given an equation like y = (1/2) (x-3)2 + 6, when describing the distortion from the base curve y = x2 is it correct to say there is a vertical compression by a factor of 2, or by a factor of 1/2 ? Which is more correct? I have seen both versions in different high school texts, and I am now unsure which is more correct. Answered by Harley Weston.
	Completing the square		2001-01-12
		From Jacky Lam: A friend told me that completing square not only can find the vertex but also the roots of a quadratic equation. Is it possible? How? Can you show me how to find the roots of the following equation using completing the square? 8x2 + 8x + 4 Answered by Penny Nom.
	64.5% profit		2001-01-12
		From Ethel: IF I PURCHASE AN ITEM FOR $2.00 AND I WANT TO RESELL IT WITH A MARGIN OF GROSS PROFIT OF 64.5% WHAT FORMULA DO I USE TO ARRIVE AT THAT RESELL FIGURE? Answered by Penny Nom.
	Blood flow and age		2001-01-11
		From Gayle: I don't understand the second part of this problem Here is the first part that was correct. A 35yr old has 100% blood flow. A 65yr old has 64% blood flow. Find the rate of change per yr in the percent of blood flow. (This part is correct) m=(64-100)/(35-65)= -36/30= -1.2 per year of blood flow. Now, here is the second part I DON'T UNDERSTAND! .Let b represent the percent of blood flow and a represent a person's age. Write an equation that you could use to predict the percent of blood flow for a person of any age over 35. Answered by Penny Nom.
	Place value chart		2001-01-11
		From Charles: Can you send me a pictorial example of a place value chart? Answered by Harley Weston.
	8, 4, 2, 18, 1, 9		2001-01-11
		From Neyra: Place each number below in one of the blanks to create the most meaningful and realistic story possible. Answered by Claude Tardif.
	A 1 from 35 lottery		2001-01-11
		From Jamie: A number is randomly drawn from an urn containing 35 balls numbered 00 to 34. How to win Division 1 Match the number drawn Division 2 Match the last digit of the number drawn Calculation of probabilities for this lottery:... Answered by Claude Tardif and Penny Nom.
	x^5 + y^5 + z^5 = w^5		2001-01-11
		From Samuel Brown: x5 + y5 + z5 = w5 I have no idea whether or not this is possible. Answered by Claude Tardif.
	The sum of all ten-digit numbers.		2001-01-10
		From John: Compute the sum of all ten-digit numbers. Can you determine the sum of all n -digit numbers? Answered by Sukanta Pati.
	Is n^2 - 2 a multiple of n - 4?		2001-01-10
		From John: Find all positive integers n so that n2 - 2 is a multiple of n - 4. Answered by Sukanta Pati.
	Four crayons		2001-01-10
		From Neyra Espinoza: You have four crayons (red, blue, yellow, green). If you line them up, how many different combinations can you get? Answered by Patrick Maidorn.
	The Pythagorean Theorem		2001-01-08
		From Megan: Why the Pythagorean Theorem so important in our lives and what is it's history? Answered by Penny Nom.
	Multiplication of fractions		2001-01-08
		From Angela: Questions: 1. represent multiplication of fractions via an area model 2. describe why, not just how, to round decimals Answered by Penny Nom.
	cot(arcsin 3/5)		2001-01-07
		From Jason: Find value. Assume that all angles are in Quadrant 1. cot(arcsin 3/5) Answered by Harley Weston.
	The city transit system		2001-01-07
		From Jacky: The city transit system carries an average of 9450 bus riders a day, for a fare of $1.75 each. The city wants to reduce car pollution by increasing ridership and to maximize the transit system's revenue at the same time. A survey indicates that the number of riders will increase by 150 for every $0.05 decrease in fare. Answered by Harley Weston.
	Women mathematicians		2001-01-07
		From Kisha: Can you please tell me names of at least five female math teachers who changed history back then? Answered by Penny Nom.
	Derfs, Enajs and Sivads		2001-01-07
		From John and Norman: All Derfs are Enajs. One-third of all Enajs are Derfs. Half of all Sivads are Enajs. One Sivad is a Derf. Eight Sivads are Enajs. The number of Enajs is 90. How many Enajs are neither Derf nor Sivad? Answered by Penny Nom.
	A dollar, quarter, dime, nickle and penny		2001-01-07
		From Sarah: Arnold has a dollar coin, one dime, one quarter, one nickel, and a penny. The number of different sums of money that can be formed using three coins is... Answered by Penny Nom.
	The pythagorean theorem in everyday life		2001-01-06
		From Josh: What are some ways that we use the pythagorean theorem in jobs, or even in everyday life? Answered by Claude tardif.
	Two questions		2001-01-04
		From Justine: first: A diagonal of a rectangle is the square root of 13 meters and the area of the rectangle is 6 meters squared. What are the dimensions of the rectangle? last: Find the ordered triple of nonzero digits (A,B,C) for which (AA)squared=BBCC where AA and BBCC are respectively, two-digit and four-digit base-ten numerals. Answered by Penny Nom.
	Three dice		2001-01-03
		From John Read: I have three dice (A, B, C.) Three sides of each dice are blank. Three sides of each dice have a number. When the dice are thrown, it must be possible to result in the numbers 1 to 49 in any combinations without doubling up on any figure. i.e. Different combinations resulting in the same end number. I managed to get from 1 to 47 before getting stuck. Answered by Claude Tardif.
	Why the change from commas between every 3rd digit, to spaces instead?		2001-01-03
		From Clarende Duby: Why the change from commas between every 3rd digit, to spaces instead? For example: Three million three hundred thirty-three thousand three hundred thirty-three written like: 3 333 333 instead of 3,333,333? Does it have something to do with standardizing mathematical notation worldwide? Answered by Harley Weston.
	30% of 80		2001-01-03
		From Denise: Could you please tell me what 30% of 80 is? Answered by Penny Nom.
	The laws of sines and cosines		2001-01-02
		From Faydene: Can the sine /cosine rule be applied to a right -angle triangle to find a particular solution or are these 'rules' applied only when the triangle is not right angled? Answered by Penny Nom.
	Filling a tank		2001-01-02
		From Liting: Water flows into a rectangle tank which measures 4 m by 3 m by 2.8 m through a cylindrical pipe of radius 2.4 cm. If the rate at which the water flows into the tank is 8 km/h, find how long it takes to fill the tank. Answered by Penny Nom.
	Polite numbers		2001-01-02
		From A student: A positive whole number, greater than 1, is said to be a polite number if it can be expressed as a sum of consecutive whole numbers Find all the polite numbers less than 21. Find a pattern in the numbers that are not polite. Explain why every odd number greater than one must be polite. Answered by Penny Nom.
	A quarter-circle and two semi-circles		2000-12-31
		From Christopher: Inside the quarter-circle are two semi-circles with the same radius, (r). Which has a greater area, G or L? Answered by Penny Nom.
	Height of the lamp		2000-12-31
		From Joey: The figure shows a lamp located three units to the right of the y-axis and a shadow created by the elliptical region x2 + 4y2 < 5. If the point (-5,0) is on the edge of the shadow, how far above the x-axis is the lamp located? Answered by Harley Weston.
	Repeating decimal notation		2000-12-31
		From Clarende Duby: I have seen single repeating decimals for ex. 1/3 = 0.3 with the dot above the 3 to represent the repeating decimal. Then, there is the more common form of the bar over the top of the repeating number or group of numbers (called the period?). Which notation is correct? Answered by Penny Nom.
	Bush fractals		2000-12-30
		From Anita Wisecup: My son has a report due on fractals. He needs information on bush fractals, but we cannot seem to find anything out about them. Answered by Penny Nom.
	Solving x - sin(x) = constant		2000-12-29
		From Keith Roble: If x is in radians, how do you solve for x, where: x-sin(x) = constant? Answered by Harley Weston.
	Solving an equation		2000-12-29
		From Bob: Would you be able to help me solve this math equation.. Solve for b, 2 [b - (q + s)] / q = s Answered by Penny Nom.
	A pair of numbers whose GCF is 28		2000-12-27
		From John: Name 2 different pairs of numbers whose GCF is 28. Answered by Penny Nom.
	Some prime conjectures		2000-12-24
		From Tarrasita: I was given some homework to investigate the following conjectures on prime numbers 1) There is at least one prime between consecutive square numbers. 2) Every prime except 2 and 3 is of the form 6n+1 where n is a natural number. 3) Any odd prime which is of the form 4n+1 is equal to the sum of two perfect squares. Answered by Harley Weston.
	A lampost and its shadow		2000-12-24
		From Laura: A lamppost line EC casts a shadow line AC. A 30 cm ruler line DB has been moved from A so that it's shadow falls just within the shadow of the lamppost. Suppose the length of the ruler's shadow is 42 cm. What is the slope of the imaginary line AE? Suppose the lamppost's shadow is 15 m. long. How tall is the lamppost? Answered by Penny Nom.
	Cats and dogs		2000-12-24
		From A student: Brian has fourteen pets. All of his pets are cats and dogs. Brian has four more cats than dogs. How many dogs does he have? Answered by Penny Nom.
	Calculating the tax		2000-12-22
		From A grocer: I have a small grocery store. I have a bag of money containing $325. This represents the mornings receipts and a tax of 5.75% is included in the total. How can I separate the gross take from the tax take so that I'll know how much is mine and how much is the state's? Answered by Penny Nom.
	How do you integrate secant(theta)?		2000-12-22
		From Robert Williamson: How do you integrate secant(theta)? I know the answer is ln [sec(theta) + tan(theta)] but how do you get there? Answered by Claude tardif.
	An infinite series		2000-12-16
		From John: summation(n=1 to infinity)[n sin(1/(2n))]n Answered by Harley Weston.
	A Trapezium problem		2000-12-15
		From Ben: A trapezium has a perimeter of 22cm. The 2 parallel sides are such that the length of one is three times the length of the other. The non-parallel sides are equal. If the distance between the parallel sides is 4cm, find the lengths of the 4 sides. Answered by Claude Tardif.
	Factoring (u-v)3+v-u		2000-12-15
		From A parent: I am a middle school teacher and a parent. I am snowed in and trying to help my 9th grader get ready for 9 weeks exams. I have tried to factor this problem to no avail. (u-v)^3+v-u. I have the answer but I need to know how it is done. Answered by Penny Nom.
	When did the man go out?		2000-12-14
		From Rajesh: A man goes out in time between 5 and 6 and when he comes back he observes that two hands have interchanged position. Find when the man did go out? Answered by Penny Nom.
	Three problems		2000-12-14
		From Sarah: Hi, my name is Sarah, and I'm asking this question on behalf of niece who is in secondary two. Thank you. Q1. What is the angle formed by the hour hand and the minute hand of a 12 hour clock at 5.50pm. . . . Answered by Penny Nom.
	What is the difference between Mean and Average?		2000-12-13
		From Julie: What is the difference between Mean and Average? My thinking is the average, is the equal to the sum of all numbers divided by the number of numbers added together. But the mean, I think should be calculated by adding the largest and smallest numbers in the set and them dividing by 2. (which is the point where 1/2 the numbers are higher and 1/2 the numbers are lower) Answered by Patrick Maidorn and Penny Nom.
	Prime factorization		2000-12-13
		From A student: What is the prime factorization for 250 1296 and 2400 Answered by Penny Nom.
	A limit using l'hopital's rule		2000-12-13
		From Wassim: I need to know how to solve the: limits of (x ( to the power lamda) -1 )/LAMDA when lamda tends to zero ( the answer is that the functional form is ln x) and I still don't know how using hopital rule leads to this answer. Answered by Harley Weston.
	Scientific notation		2000-12-12
		From Guy: How do I express 1.000.000 in scientific notation? Answered by Harley Weston.
	Direct and inverse variation		2000-12-12
		From Ashley: I'm stuck on this unit of direct and inverse variation..please and my problems and show me how to do each PLEASE!!! Assume that y varies directly as x If y= -4 when x = 2, find y when x= -6 Assume that y varies inversely as x If y =-4 when x=2, find y when x =-6 Answered by Penny Nom.
	Divisibility by 16		2000-12-12
		From Shiling: A number can be divided by 16 if and only if its 1st four digits can be divided by 16. How can you prove that? Answered by Penny Nom.
	A chemist had 8 flasks		2000-12-10
		From Jimmy: A chemist had 8 flasks capable of holding 12, 15, 27, 35, 37, 40, 53 and 69 fluid ounces respectively. He filled some with water and then filled all the rest except one with alcohol. He used exactly one and a half times as much alcohol as water. Which flask was left empty and which were left with water and which with alcohol? Answered by Claude Tardif.
	Volume of a trough		2000-12-09
		From Matt: I have been given the information of the length of the trough, and the end pieces are isosceles triangles, and two equal sides of the triangle are given. I cannot seem to find the answer, nor anything in my book relating to the question. Answered by Harley Weston.
	Mixed Fractions		2000-12-09
		From Tim Finch: My son is having problems with mixed decimals and mixed fractions.. I am unable to find any information or examples on this subject so I can show him how to do it.. for example how do you make a mixed decimal or fraction out of 7/16 Answered by Penny Nom.
	Is this a right triangle?		2000-12-08
		From Alicia: How would you set-up and answer a problem like these one? Triangle ABC has vertices A(-2,2), B(1,-2), and C (1,2). Use slopes to determine if the triangle is a right triangle. Answered by Penny Nom.
	Networks of satellites and linear spaces		2000-12-08
		From David: Let us suppose some companies have collaborated to place several satellites in orbit. Let us call the set of all satellites that a given company helped place in orbit a network. Finally let us assume the following 4 rules. There are at least two distinct satellites. For each pair of satellites there is exactly one network containing them. Each network contains at least two distinct satellites. For each network, there is a satellite not in it. What is the least number of satellites. what is the least number of networks? Answered by Penny Nom.
	Fibonacci		2000-12-07
		From A student: Can you give me any info about Fibonacci?? Answered by Penny Nom.
	Kai's bike		2000-12-07
		From Fumiko Muhammad: The wheels on Kai's bike are 27 inches in diameter. His little sister, Masako, has a bike with wheels that are 20 inches in diameter. a. How far will Kai go in one complete turn of his wheels? b. How far will Masacko go in one complete turn of her wheels? c. How far will Kai go in 500 turns of his wheels? d. How far will Masako go in 500 turns of her wheels? Answered by Penny Nom.
	Pizza delivery		2000-12-07
		From Meghan: 3 men give 10 dollars each to a pizza deliver driver and when he gets back to his work the manager says to the pizza driver the bill was actually 25 dollar so he has to returns 5 dollars. on his way to the mens house he the driver decides to kept 2 dollars for himself and he gives 1 dollar back to each of the men. So each one of the men actually paid 9 dollars. but 9 times 3 is 27 plus the other 2 that the driver took equals 29 so where did the other dollar go. Answered by Harley Weston.
	Optical illusions		2000-12-06
		From Jessica: Hi, my name is Jessica, 7th grade, and Im doing a Math Fair project on optical illusions. As one of the required factors, we need a "mathmatical significance" paragraph. Unfortunatley, I can only think of one way that optical illusions have to do with math, and thats time because some optical illusions tell you to look at the picture for a certain amount of time. Answered by Penny Nom.
	< and > Which one is which?		2000-12-06
		From Alice: This grandmother forgot and wants to know the correct for greater and the one for lesser..... the two are < and > Which one is which? Answered by Penny Nom.
	A point that a group of lines pass through		2000-12-05
		From Ross: A point that a group of lines pass through is called a________? Answered by Chris Fisher.
	Scheduling a golf vacation		2000-12-05
		From Michael: I'm having a problem scheduling matches for a golf vacation. We have 12 people playing 7 rounds of golf in 7 days. We play 2 man teams vs. 2 man teams everyday.Is there a formula so that you play WITH a different partner everyday and AGAINST as many different people as possible? Thank You for any help you may be. Answered by Penny Nom.
	Calculating your grade		2000-12-04
		From Jack: I got an 80 on test 1 and a 65 on test 2. The first test is worth 35% of our total grade and the second is worth 40%. What is my grade right now? Answered by Penny Nom.
	The aspect ratio of a rectangle		2000-12-04
		From Ron Delavigne: The aspect ratio of this rectangle is 4:3. That is A to B is 3. And B to C is 4. If I know the lenght of A to C is 19 inches, how can I find the length of A to B, and B to C. Answered by Penny Nom.
	Parabolas in life		2000-12-03
		From Ashley: I am a student and my teacher recently gave us the assignment of writing a portfolio on parabolas in life and finding examples, three to be in fact, only we have to go into detail about only one. We have been instructed to include such terms as: axis of symmetry, completing the square, parabola, quadratic formula, standard form (vertex form) and vertex. We also must include in our detailed example an equation of the parabola and very specific details, PLEASE HELP! Answered by Harley Weston.
	Equivalent fractions		2000-12-03
		From A student: please explain to us how to find the answer to this problem, we need three fractions that name the same amount as 2 Answered by Penny Nom.
	Estimating the time to complete a job		2000-12-03
		From Jack Hook: I'm a contractor and need to estimate how much time it will take me to do a specific job. A previous job I did was 6,480.16 Square Feet and I was able to paint it in 31.5 hours. In estimating my next job, how many hours will it take me to paint 11,000 Sqare Feet. Answered by Penny Nom.
	A non-integrable function		2000-12-03
		From Mark Spilker: I have a proof that I cannot do here it goes. Let F(x)= 1 if x is a rational number 0 if x is an irrational number Prove the function is not intregrable on the interval (0,1). Hint: Show that no matter how small the norm of the partition, the Riemann Sum for the SigmaNotation F(wi) DeltaiX is not unique. Answered by Harley Weston.
	Two more problems		2000-12-01
		From Michael: first question: The mean of three test grades is 74. What must a fourth grade be to increase the mean to 78? final question: The product of two consecutive odd positive integers added to their sum is 119. What are these two integers? Answered by Claude Tardif.
	Triangles and trigonometry		2000-11-30
		From Mose: If I have a right triangle, and I know the lengths of all three sides, is there a formula that will allow me to determine the measurements of the 2 non right angles? Answered by Harley Weston.
	A 16 slice pizza		2000-11-30
		From A student: What is 5/8 of a 16 slice pizza? Answered by Penny Nom.
	An integration problem		2000-11-30
		From A student: If a>0 and the integral from b to 0 of 1/(1+x) equals 1/2 the integral from a to 0 of 1/(1+x), express "b" in terms of "a" Answered by Claude tardif.
	The astronomers' calendar		2000-11-29
		From Show_Li: The calendar that astronomers use began on Jan. 1, 4713 B.C. on that day, the julian calendar, the lunar calendar, and roman tax system calendar all coincided. This won't happen again until 3267 A.D. (a). How many years ago was the astronomer's calendar started? (b). Find the number of years between times that the three calendars coincided. Answered by Penny Nom.
	Trig identity crisis		2000-11-29
		From Rhiannon: I have tried many times to find the answer to these problems but I can't I am in grade 12 tan(x)=csc2(x)-cot2(x) cos(x)/csc(x)-2sin(x)=tan(x)/1-tan(x) cos(x)[ tan2(x)1-1]/cos2(x)+sin2(x)=sec(x) Answered by Harley Weston.
	Vector Problem		2000-11-27
		From Ben: An aircraft can fly 260km/h in still air and the wind is blowing at 70km/h towards the West. In what direction should the aircraft head so that its actual velocity is on a bearing of 030 degrees? Answered by Harley Weston.
	Power series representations		2000-11-27
		From Grace: Is there a systematic way of finding a power series representation of a function? I understand that you have to manipulate the function so that it is of the form 1/(1-x), but beyond that I am lost. Answered by Harley Weston.
	Order of operations		2000-11-26
		From Margaret Pratt: My daughter has a math question and I am afraid I am of no help. Can you help? 2x5/2+1-5= She arrives at 8 as the answer and has been told this is incorrect. Any help you can give would be appreciated. Answered by Penny Nom.
	A complex calculation		2000-11-24
		From Angie: Multiply (3-2i)2=32-2(3)(2i)+(2i)2 Answered by Penny Nom.
	A piecewise linear equation		2000-11-24
		From Jacky: There is a light bulb and it is given that the light bulb cost $0.75 and the cost of operating it is $0.0081 per hour. From the information give, I came up with the linear equation: Let c be total cost and Let h be hours used. Therefore: c = 0.0081h + 0.75 represents the total cost of the light bulb and the electricity. However, the second part of the question added the fact that the light bulb will only last for 800 hours. If the light bulb is replaced as soon as it burns out exactly after every 800 hours, how can I write an equation that represents that? Is it possible? What would it look like on the graph. Answered by Harley Weston.
	What are adjacent angles that equal 360 called?		2000-11-22
		From David: I know that supplementary angles add to 180 degrees and that commplementary angles add up to be 90 degrees, but what are adjacent angles that equal 360 degrees called? Answered by Chris Fisher.
	Comparing an integral and a sum		2000-11-21
		From Douglas Norberg: A fellow teacher asked me about a problem she wanted to give to her students. It involved whether to take a million dollars or a penny doubled a number of times. I was able to determine the number must have been .01 * 230 which is about $10 million and a lot more than $1 million. To check that I was right I used a spreadsheet and did a Riemann sum. When I finished I reasoned that I had done the task in several steps and I could have done it in 1 step. Thus I integrated .01 * 2x from 0 through 30 but the number I got was $15,490,820.0324. Why the difference? Answered by Harley Weston.
	5 spades		2000-11-21
		From Matt: In a standard deck of 52 card how many would you have to draw (without looking at them) to be absolutely certain that you had 5 spades? Answered by Claude Tardif.
	Range of a function		2000-11-21
		From David Bell: Given a rational function such as f(x) = (8x-3)/(4x-1). How can the range be found. Answered by Penny Nom.
	Net, gross and vat		2000-11-20
		From Chris: I have my gross but want to find out the net so I know how much the VAT is? Answered by Penny Nom.
	Integral solutions		2000-11-20
		From David: determine all pairs of integers (x,y) which satisfy the equation 6x2 - 3xy - 13x + 5y = -11 I got y= (6x2-13x+11)/(3x-5) and i don't konw how to continue Answered by Claude Tardif.
	Permutations vs. combinations		2000-11-20
		From Ashleigh: How do you tell whether the problem is a permutation or a combination? Answered by Walter Whiteley.
	Bridges and parabolas		2000-11-18
		From Lauren: My name is Lauren, and Im a secondary school student in Ontario. For my gr11 advanced math class I have to find out how and why parabolics are used in arch bridges and write 3 paragraphs on it. People who cohse satelites and whatnot are lucky - I've found a ton of info, but for arch bridges there seems to be nothing. Answered by Harley Weston.
	Find the 3D angle		2000-11-18
		From Jacky: Included is the diagram. I am trying to find out the angle of ABC. Is it possible? How? Answered by Penny Nom.
	Inscribing a circle in a rhombus		2000-11-16
		From Jacky: A rhombus ABCD is drawn in which the diagonals are 12 and 20 units long. A circle is inscribed in the quadrilateral with the centre of the circle right on the intersection point of the 2 diagonals. The circumference of the circle touches all 4 sides of the rhombus. Is it possible to find the radius of the inscribed circle? If so, how and what is it? Answered by Chris Fisher.
	Expanding a garden		2000-11-16
		From Janeth Rojas: Mr Jones's garden has an area of 21 squares meters. He wants to increase its size by 1/2. Draw a picture to show what his new garden might look like. Be sure to give the new area and demensions, and show your reasoning. Answered by Penny Nom.
	Volume of a box		2000-11-15
		From A student: A box 3" wide and 2" deep is to have a volume of 2 cubic feet. How long must the box be? How many pieces of lumber are stacked in a pile 2" high if each board is 3/8" thick? Answered by Penny Nom.
	Dividing with decimals		2000-11-15
		From Alex: I teach math and my class and I were discussing the dividing of decimals. I explained that if there is a decimal in the divisor, it needs to be moved and so does the decimal in the dividend. My question is why is it necessary to move the decimal point in the divisor before dividing? Answered by Penny Nom.
	Domain of a function		2000-11-15
		From Mickey: state any restrictions on the domain of the function. y = 5x - 12 over 27x + 6 x does not equal what________? Answered by Penny Nom.
	Henri Leon Lebesgue		2000-11-14
		From Mandy: I have a report that I have to do on Henri Leon Lebesgue for my Foundations of College Math class. I have searched for him on erols, google, yahoo and a few other search sites and I have only come up with one page that offered some information. I was wondering if anyone knew anything about him, or a web page that I could get some info. Answered by Harley Weston.
	Solving an equation		2000-11-14
		From Heather: 4x-3 = 3x+4 these kinds of problems i dont get but everything else in my math class i have got. i just dont understand it. Answered by Penny Nom.
	Five digit palindromes		2000-11-12
		From Jacky: Positive integers such as 1287821 and 4554, in which the number is unchanged when the digits are reversed, are called palindromes. The number of five-digit integers larger than or equal to 10,000 which are not palindromes is... a. 10 000 b. 81 000 c. 89100 d. 90 000 e. 99 100 Answered by Penny Mom.
	Static electricity on an airplane		2000-11-12
		From John: What discharges an airplane of static electricity in a electric storm when it is flying. I assume the charge is on the out side of the plane but when does it get discharged, or does it occur at landing? Answered by Ted Mathie.
	Euler's Formula		2000-11-11
		From Denise Roberts: I'm trying to design a unit (possibly involving a Webquest) on Polyhedra and I cannot find a formula I once used. The formula involved the number of vertices (V), edges (E), and faces (F) of the polyhedra. Answered by Walter Whiteley.
	The magnitude of a complex number		2000-11-11
		From Jeremy: Recently, we started studying how to graph complex numbers. Our math teacher said to use what would normally be the x-axis as the real-axis and to use the y-axis as the imaginary-axis. However, when he started talking about how to calculate magnitude, that's when I became confused. For instance... Answered by Walter Whiteley.
	Infinite Geometric Series		2000-11-10
		From Sam Carter: I ran into a problem when studying how to find the sum of an infinite geometric series. My math book attempts to explain the concept by giving formulas involving sigma and |r|, but it does not really explain how to go about finding the sum of an infinite geometric series. If you could either help me with this or point me in the direction of an informative website that could help me, I'd appreciate it. Answered by Harley Weston.
	Rhombuses		2000-11-07
		From Melissa: What in real life is the shape of a rhombus? Answered by Chris Fisher and Walter Whiteley.
	How big is a trillion?		2000-11-07
		From A teacher: How can you explain how much a trillion is to a 5th grade class? Answered by Penny Nom.
	Parking spaces		2000-11-07
		From Lydia: A parking lot has 4 aisles. Each aisle is about 40 yards long and has parking places on both sides. If a parking place is 3 yards wide, how many cars can the parking lot hold? Answered by Penny Nom.
	How many tens are in 400?		2000-11-07
		From A student: How many tens are in 400? Answered by Penny Nom.
	Crown molding mitre cuts		2000-11-06
		From Jim Tomfohrde: My question has to do with making mitre cuts when installing crown molding. Crown molding is the trim that is put up at the top of walls with one edge on the wall and the other edge on the ceiling. To make a mitre cut on your mitre saw for a 90-degree corner you can lay the molding flat on the saw base, set the bevel of the blade to 34 degrees and the mitre to 31.5 degrees (these may be slightly appoximate). Of course depending on which piece of molding you're cutting you will cut one end or the other, or use the left or right end. These angles allow the cuts to line up and form a seamless corner when they're put in place on the wall/ceiling at 90 degrees. My question is this - is there some mathematical formula from which the 34 degrees and 31.5 degrees are derived. I want to know this because in many cases the corner is not 90 degrees but can be more or less, and in these instances I would like to know if I can calculate the bevel and mitre to use based on the angle of the corner. Answered by Harley Weston.
	Graphing F(x) = 3x		2000-11-06
		From Jose: graph the exponential problem F(x)=3x Answered by Harley Weston.
	Banana yogurt		2000-11-03
		From James: A grocery store has 100 cartons of banana yogurt in stock.Each carton contains 12 cup of banana yogurts.The probability that a cup has fewer than 20 banana chunks in it is 10 %. So,What is the probability that between 15 and 25 (inclusive) cartons out of the 100 cartons have exactly 3 cups with fewer than 20 banana chunks? Answered by Harley Weston.
	Expected number		2000-11-02
		From James: 1)There are 40,25,50 students in the traditional,reformed,and reformed traditional Calculas sections taught by three teachers. On one fine day the three sections congregate together to watch the NOVA video tape on Fermat's Last Theorem. a) A student is randomly selected from he crowed of students.What is the expected number of students in the same section of this student? ****this question which i did not have any idea to do as follow for the part b b) If one of the three teachers is selected at random, what is the expected number of students taught by is teacher? Answered by Harley Weston.
	Two problems		2000-11-02
		From Michael: Question: I mistakenly divided a number by 5 when I should have multiplied by 5. FInd my percent of error. Next Question: How many odd numbers are between 10 and 9,999 from the digits 0-9 if each digit is used once per number. Answered by Penny Nom.
	Length of a shadow		2000-11-01
		From Jessy: A man who is six feet tall is walking away from a street light that is fifteen feet tall. How long is the man's shadow when he is ten feet away from the light? Answered by Penny Nom.
	Symmetry		2000-11-01
		From A student: I am a 6th grader look for material on mathametical symmetry . Most of the material I have found is science related . I have to write a paper on this . Any resource info you could lead me to would be helpful. Thank you for your time. Answered by Chris Fisher.
	Perfect numbers		2000-10-31
		From A student: I was wondering if you could help me answer a question my pre-algebra teacher asked in class the other day. He asked if we knew what the perfect numbers where. He told us the first number is 6 the second number is 28 but the third he did not tell us. Do you know what the third perfect number is? Answered by Paul Betts and Chris Fisher.
	Factoring a cubic		2000-10-31
		From A student: Factor Completely 18p3 - 51p2 - 135p Answered by Paul Betts and Penny Nom.
	Lobbing a tennis ball		2000-10-31
		From Alex: If a tennis ball is lobbed into the air with an initial upward velocity of 12 meters per second, its velocity and height will be functions of time in flight described by the following rules: V=12-9.8T and H=1+12T-4.9T 2 Find the maximum height of the tennis ball and the time it takes to reach that height. Answered by Penny Nom.
	False Positives		2000-10-29
		From James: A rare disease infected 1 in 1000 people in the population. A test for the disease is accurate 99% of the time when given to an infected person and also when given to a heathy person. Fill out a two-tier tree diagram and find the probability of the false positive(i.e the conditional probabily of being healty even when tested postive by the test) Comment on the result? ... Answered by Penny Nom.
	Square roots		2000-10-29
		From Pamela: HERE GOES(I WILL USE Q AS THE SYMBOL FOR SQUARE ROOT): 8(Q2) - 5(Q2) + Q2 SECOND PROBELM IS (1 + Q2)2 LAST ONE 3/(2-Q5) Answered by Claude Tardif.
	Overlapping a circle and a square		2000-10-28
		From Jacky: A square with a dimension 20 by 20cm. and a quarter of the circle with the radius of 25cm (A quater of a circle is created by 2 cuts that are perpendicular bisectors of each other where the intersecting point is at the centre of the circle). With these 2 pieces, the 2 pieces are placed over each other in which the 90o angle of the quarter circle matches with one of the right angles on the square. Now, calculate the overlapping area of the 2 figures. Answered by Chris Fisher and Harley Weston.
	Find the rule		2000-10-27
		From Kelsa and Linda: Find the rule: It had 13 in a circle then 2 blank circles then 31 in a circle then two more blank circles. Could you please help us. Answered by Penny Nom.
	Developing a community garden		2000-10-26
		From adam: Robin's class is developing a community garden. There are 15 students in Robin's class. They volunteer to work in a community garden at various times during the school week. Robin's teacher says it will take about 3 weeks to complete the project if 3 students work 1 hour each day. Some students can work on more than one day. The following table lists the number of students who can work on various days. . . . Answered by Penny Nom.
	Cutting the lawn		2000-10-26
		From Kacie: Ellen can mow a lawn in 2 hours. Mary can mow the same lawn in 1.5 hours. How long would it take them to mow the lawn together? Answered by Penny Nom.
	A zip code problem		2000-10-26
		From Rob Mathis: Find the zip code of a place in a county so that the product of it and the zip code of another place in another county of the same name, but in a different state, is an exact multiple of the number 123456789 Answered by Claude Tardif.
	The ages of three daughters		2000-10-25
		From Andrea: An encyclopedia saleman call at a home. The woman who answers the door says she will buy something from him if he can give the ages of her three children. The first clue, she says, is the three ages multiplied together equal 36. he responds that he needs more infomration, so she says that the threee ages add up to the number of the bus that passed by (the prof did not give us this number) He thinks for a while and says he needs one more clue. So she says, my youngest child has red hair, and he is able to answer and make the sale. what are the ages of the three children? (hint: the salesman needed all three clues to get the answer). Answered by Penny Nom.
	Assessment and portfolios relating to math		2000-10-24
		From Jackie: I will be assisting in a presentation for grades 4-6 on assessment and portfolios relating to math. If anyone has some ideas will love to hear them. I have checked out a few sites on the net Answered by Diane Hanson.
	Divisibility by 9		2000-10-24
		From Kelera: If the sum of the digits of a number is divisible by 9, then the number itself it divisible by 9. Why is that? How do you explain this? Answered by Penny Nom.
	A sequence question		2000-10-23
		From Chell: I have the following sequence: 4 16 37 58 89 145 42 20 I have no clue how to arrive at an answer. I've checked to see if it can be defined as an arithmetic or geometric series, and it can't. I've looked for primes and noticed that 37 and 89 are the only primes ... but from there I've lost. Nothing I've tried seems to work, so please help! Thanks a million!!!! Answered by Chris Fisher.
	Working together on a job		2000-10-23
		From Nicole: WORKING TOGETHER ON A JOB: Patrice, by himself can paint 4 rooms in 10 hours. If he hires April to help they can do the same job together in 6 hours. If he lets April work alone , how long will it take her to paint 4 rooms? Answered by Claude Tardif.
	Concavity		2000-10-22
		From Alex: the question is: on what interval is f(x)=(x2)(ex)? ive found the 2nd derivative which is ex(x2+4x+2) and i did the quadratic to get -2-20.5 and -2+20.5, but i dont know what the interval is. Answered by Harley Weston.
	Tapes and CD's		2000-10-22
		From Arnold: Nicole has 25 CDs and tapes altogether. When she tries to pair them up, she has 4 CDs left over. How many tapes does Nicole have? Answered by Penny Nom.
	The scale on a map		2000-10-21
		From Caroline: On a map scale of 1:15000 the distance between two buildings is 31.4cm what is the actual distance in km. Answered by Penny Nom.
	Connecting to a water line		2000-10-20
		From Vanja: My question is...A house is to be connected to a new water main that runs along the line y=2/3x-1. The connection point at the house has coordinates (2,9), where the units represent metres. What lenght of plastic pipe is needed to connect to the water main at the closest point? Answered by Penny Nom.
	The perimeter of a football field		2000-10-18
		From Paige: The width of a football field is 67ft greater than the length. The perimeter is 480ft What is the width and length? Answered by Penny Nom.
	Dividing fractions		2000-10-18
		From Paula: Why do you have to change the division sign to a multiplication sign and invert the fraction that follows the division sign in order to get the answer to a division problem when you're working with fractions? Answered by Penny Nom.
	Transporting bananas		2000-10-18
		From Krystie: A farm has 45 bananas, a man has to take a truck and transport 15 bananas to a market that is 15 miles away. Every mile he travels, he must eat a banana. I have to get at least one banana to the market Answered by Penny Nom.
	A chord length		2000-10-17
		From Al Paas: How to determine the length of a chord given the diameter of the circle and the maximum distance from the chord to The circle? Answered by Chris Fisher.
	Multiplying decimals		2000-10-16
		From Lily: I need help with mutiplying decimals (example) 2.28*0.48( * = times). Answered by Harley Weston.
	Area of shapes		2000-10-14
		From Melanie: What is the formula to calculate the area of different shapes? Answered by Harley Weston.
	2-step equations		2000-10-11
		From Jen: i don't get how you find the answer to these equations 140= -4 -12e x/-2 + 6 = 4 Answered by Penny Nom.
	Where will we use this in the real world?		2000-10-11
		From Jane Ann Musgrove: As a teacher of mathematics, I am always asked "Where will we use this in the real world?". I am seeking ideas/sites via the internet where students can find answers to this type of question. Can you help me? To be more specific, right now I am interested in finding careers where the employees would use the concepts of "Radicals", "Matrices", and "Logarithms". This information will be used by students to make presentations to the class on their findings from internet searches. Answered by Harley Weston.
	Larger and smaller		2000-10-10
		From Nicole: which one of these arrows < , > points to the greater number? which arrows points to the smaller number. Answered by Penny Nom.
	The sum of the cubes is the square of the sum		2000-10-10
		From Otoniel: Without using mathematical induction, or any other method discovered after 1010 a.d. , prove that the sum of i3, (where i, is the index of summation) from one to, n, is equal to ((n*(n+1))/2)2 Answered by Penny Nom.
	Hendecagon		2000-10-09
		From Jillian: I need an example of a object that is in the shape of a hendecagon. I know what the shape is but I cannot come up with a real life example of an object that is this shape. Answered by Chris Fisher.
	Sunflower seeds		2000-10-09
		From A parent: Find the number of 3/4 pound of sunflower seeds that can be filled with 225 pounds of sunflower seeds Answered by Penny Nom.
	Independent tests		2000-10-07
		From A student: If the false-positive rate of each test in a battery of tests is 0.05, how many independent tests can be included in the battery if we want the probability of obtaining at least one false-positive result to be at most 0.2? Answered by Harley Weston.
	Repeating decimals		2000-10-06
		From Mary O'Sullivan: I understand that with repeating decimals (those with a pattern), the number of digits repeated is put into fraction form with the same number of 9's ex. 0.4444 = 4/9 0.145145145 = 145/999 How can I explain why this is so? Some inquisitive 8th graders are anxious to find out! Answered by Penny Nom and Walter Whiteley.
	Cutting the cake		2000-10-05
		From Cherie: How can you divide a cake (circle) into 14 pieces by using only 4 straight lines? Answered by Penny Nom.
	Pillows and Cushions		2000-09-27
		From Fiona: The following problem was given to grade eleven algebra students as a homework assignment. To manufacture cushions and pillows, a firm uses two machines A and B. The time required on each machine is shown. Machine A is available for one full shift of 9.6 hours. Machine B is available for parts of two shifts for a total of 10.5 hours each day. Answered by Harley Weston.
	Isolating an exponent		2000-09-24
		From C. Scott: Suppose you invest $500.00 in an account that pays 10% interest compounded annually. How long will it take for this value to triple? A=p(1 + i)a A=1500 i=0.1 1500=500(1.1)a p=500 a=unknown How do you solve this problem algebraicly? How do you isolate the variable (a) when it is an exponent? Answered by Harley Weston.
	Maclaurin series again		2000-09-23
		From Jason Rasmussen: I suppose my confusion comes into play when I am trying to figure out where the xn term comes from. I know that the Power Series notation is directly related to the Geometric Series of the form sigma [ brn ] where the limit is b/(1-r) for convergence at | r | <1. Therefore, the function f(x) needs to somehow take the form of b/(1-(x-a)), which may take some manipulation, and by setting r = (x-a) and b = Cn, we get the Geometric Series converted to the Power Series. Taking the nth order derivative of the Power Series gives Cn = fn(a)/n!. There must be a gap in my knowledge somewhere because I cannot seem to make f(x) = ex take the form of f(x) = b/(1-(x-a)). Maybe I should have labelled my question as "middle" because it may be more of a personal problem with algebra and logarithms. Or, am I to assume that all functions can be represented by sigma [fn(a) * (x-a)n / n!]? Answered by Harley Weston.
	BEDMAS		2000-09-22
		From Monica Zimmer: In the Math rule BEDMAS does it matter if you do the division or the multiplication first? Answered by Penny Nom.
	Mode		2000-09-22
		From James Barton: I have always been told that a mode is the "one" number that appears most in the set of numbers: ex.{1,3,4,6,3,2} the mode is 3. What if you have {1,1,3,4,5,5}is there a mode. I was taught long ago that there is no mode, Not i am having to teach there is two modes. 1 and 5. If this is the case if we have {1,1,2,2,3,3,4,4,5,5} that every number is the mode. True or false. This is being ambigiuous if we say all are the mode. Because no one number is used more than the others. Answered by Claue Tardif and Harley Weston.
	Permutations and Multiplication Principle		2000-09-22
		From Candice: A forester selects 4 pink and 4 white dogwoods. The trees are to be planted in row. If a tree is distinguished by color only, in how many ways can the eight dogwoods be planted? How many of these arrangements have at least two trees of the same color side by side? Answered by Denis Hanson and Claude Tardif.
	Dividing a region in half		2000-09-21
		From Kerry: There is a line through the origin that divides the region bounded by the parabola y=x-x2 and the x-axis into two regions with equal area. What is the slope of the line? Answered by Penny Nom.
	A Maclaurin series		2000-09-21
		From Jason Rasmussen: I have a question regarding power series notation for certain functions within the interval of convergence. Answered by Harley Weston.
	Leap Year		2000-09-20
		From Jennifer: The earth revolves around the sun in 365.24 days. How does our calendar deals with the extra 0.24 day? Answered by Penny Nom.
	A cycloid in Cartesian form		2000-09-20
		From Billy: The parametric equation of cycloid is given: x=r(t-sint) y=r(1-cost) How to eliminate t? Answered by Harley Weston.
	Arithmetic in base 5		2000-09-20
		From Lesley Emerson: my daughter is 9 and has been aske to solve the following in base 5 3+2 4+10 . . . Answered by Penny Nom.
	A proof that 1=2		2000-09-19
		From sporky: Why does the proof for 1=2 not work? x = 1 x2 = 1 x = x2 1 = 2x (derivitive) 1 = 2(1) 1 = 2 ??? please tell me where the false logic is. Answered by Walter Whiteley.
	Order of operations		2000-09-19
		From Nicole: the problem is, 4x8-18 divided by 6= do you solve this by doing 4x8=32 then by dividing 18by 6= 3, then subtracting 3 from 32 = 29? If not what is the order of operation? Answered by Penny Nom.
	Circular Permutations		2000-09-18
		From J. Stuart: I am able to understand the simple theory behind circular permutations (that is, there are (n-1)! ways to arrange n people in a circle. One question, however, is giving me some difficulty. It reads: In how many ways can four married couples be arranged around a circular table if each man must sit beside his wife? Any suggestions you have would be greatly appreaciated. Answered by Penny Nom.
	Buying art supplies		2000-09-18
		From Travis: An art teacher buys exactly 100 items at this sale, and the total cost before tax is $100. She buys at least one of each item. How many of each item does she buy? Markers $0.50 Sketch Pads $3.00 Paint Sets $10.00 Answered by Denis Hanson.
	Probability of a square		2000-09-18
		From Nick: What is the probability that four different points chosen at random from the fifteen equally-spaced points shown are the vertices of a square? I need to have my answer expressed as a common fraction. Help! I don't know how to write it. . . . . . . . . . . . . . . . Answered by Penny Nom.
	Review problems		2000-09-18
		From Dee: A card is selected from an ordinary deck of cards. What is the probability of. . . selecting 2 aces in a row? If you toss two dice, what would be your probability of the following? . . . Answered by Penny Nom.
	Mr. Edgecomb's math exam		2000-09-17
		From Rachel: In Mr. Edgecomb's math class, 30 students took an exam on statistics. If the average passing grade was 84, the average failing grade was 60, and the overall average was 80, how many students passed the test? Answered by Penny Nom.
	Tessellations		2000-09-17
		From Lindsay: What is the word that means a shape repeated over and over again to make something like a quilt pattern? Note: I'm pretty sure it is either a fractal or tesselation. Could it be that the pattern itself is a fractal but the entire quilt would be a tesselation? Answered by Chris Fisher.
	1234567890		2000-09-14
		From Bradley Kloetzly: Can you find two whole numbers, with the smallest possible difference between them, which when multipled together equal: 1234567890? Answered by Harley Weston.
	6-49		2000-09-14
		From Steve: In our state lottery you must choose 6 numbers (1-49). How many different combinations are there? They can be in any order. Answered by Harley Weston.
	Rounding		2000-09-14
		From MaryAnn: How many whole numbers rounded to the hundreds place, round to 400? Can you also explain why? Answered by Penny Nom.
	Two linear equations		2000-09-14
		From David Dean: 2a + 1b = 3.39 3a + 3b = 6.59 What formula do I use to find what a = ? Answered by Harley Weston.
	The smaller of a and b		2000-09-14
		From Jenna: For any two real numbers, a and b, give a mathematical expression in terms of a and b that will yield the smaller of the two numbers. Your expression should work regardless of whether a>b, a Answered by Penny Nom.
	Rational Numbers		2000-09-14
		From Josh Kuhar: How can you tell a number is rational? Answered by Harley Weston.
	1 + 2 + 3 + ... + 50		2000-09-14
		From Vicki Charron: How can you calculate the total of the numbers one through fifty, without adding up the individual numbers? Answered by Penny Nom.
	7 - - - - 77		2000-09-13
		From Peter: Does anyone know how to solve the following: 7 _ _ _ _ 77 ? I have to find the missing values. Answered by Chris Fisher and Walter Whiteley.
	4-digit numbers using 7, 8, 9 and 0		2000-09-13
		From Ryan: Could you please help me with the following problem, How many different 4-digit numbers are there that use each of the digits 7,8,9,and 0? Please list them. Answered by Penny Nom.
	Manipulating powers		2000-09-13
		From Phil: 21/5 x 42/5 = ? Answered by Penny Nom.
	Flim		2000-09-12
		From Jodi and Ari: Can you tell us the definition of the word FLIM? My daughter is in 4th grade, and this came up. Could not find it in the Websters Dictionary. Answered by Chris Fisher.
	Selling chickens		2000-09-12
		From Rick: A man raised chickens. He sold all but 8 of them. The first buyer bought 1/3 of all the chickens + 2/3 of a single chicken. The second buyer bought 1/3 of the remaining chickens + 1/3 of a single chicken. The third buyer bought 1/3 of the remainder + 2/3 of a chicken. How many chickens did the seller own before selling any? All chickens were alive and whole when the buyers received them. Answered by Penny Nom.
	Logs and trig functions		2000-09-12
		From Becky: How do they get these answers? log 8 + log 2 = ? Answer is: log 16 For 0 degree < x < 90 degree, how many solutions are there for the equation 2sin x = cos x? Answer: 1 Answered by Penny Nom.
	Factoring		2000-09-12
		From Melissa: I would like you to help me factor (x 6-y 6) & (a+b)2+3(a+b)-4 Answered by Penny Nom.
	Two geometry problems		2000-09-09
		From Becky: What are all the real values of x that are solutions for the inequality [x-2] < 6? ( it's less than or equal to) What is the distance between the points with (x,y) coordinates (3,-2) and (-3,-1)? Answered by Peny Nom.
	Induction		2000-09-07
		From Joe Peterson: How do I prove by the principal of mathematical induction? 1.n+2.(n-1)+3.(n-2)+.....+(n-2).3+(n-1).2+n.1=(n(n+1)(n+2))/6 Answered by Paul Betts.
	How many 17's and 19's total 1000?		2000-09-07
		From Jonathan: My question is: what 2 numbers would multiply 17 and 19 for a total of 1000. The numbers should not contain any decimal. Answered by Penny Nom.
	Roots of x^2 + 22 x + 112		2000-09-07
		From Brian R.: I need to find the root of the quadratic equation of a square. The problem is x2 + 22x + 112 = 0. Answered by Penny Nom.
	Trinomial		2000-09-06
		From Lea: I need to find the trinomial value of k which makes a perfect square. The problem is x2 - 6x + k Answered by Penny Nom.
	Derivatives, there must be an easier way		2000-09-06
		From Brad Goorman: The direction read: Take the derivative of each expression. y = {1+[x+(x2 +x3)4]5}6 Answered by Harley Weston.
	Euclidean distance		2000-09-06
		From Velma Zahirovic-Herbert: If d(x,y) is euclidean distance between x and y Prove that d(x,y)>=0 if d(x,y)=0 than x=y and d(x,y)=d(y,x) Answered by Paul Betts.
	Gravity		2000-09-06
		From Robert Broomfield: If they dropped a 1lb object from 40,000 feet in the air, at what speed would it it the ground? Answered by Harley Weston.
	n3 + 2n2 is a square		2000-09-04
		From David Xiao: determine the smallest positive integers, n , which satisfies the equation n3 + 2n2 = b where b is the square of an odd integer Answered by Harley Weston.
	Making milkshakes		2000-09-04
		From Linda: To make a chocolate milkshake, 3 parts chocolate syrup are mixed with 2 parts malt. To make a vanilla milkshake, 2 parts vanilla syrup are mixed with 1 part malt. If equal parts chocolate and vanilla milkshakes are mixed, what is the proportion of malt to milkshake? Answered by Penny Nom.
	A equation with a square root		2000-09-03
		From Lea: Please help with 2 plus the square root ( and under it has x plus 1) = 6 Thank you Answered by Penny Nom.
	Inequalities		2000-09-02
		From Jennifer: I would like some help with equations and inequalities. My first inequality is 3p-6>21 and 3q+11+8q>99. Answered by Paul Betts.
	A number problem		2000-09-02
		From Lalita Balu: Can you arrange 1234567890 to add up to 100? Answered by Penny Nom.
	Trigonometry		2000-09-02
		From david: determine the sum of the angles A,B where 0 <= A , B <= 180 (degrees) sinA + sinB = sqr(3/2) , cosA + cosB = sqr(1/2) Answered by Chris Fisher.
	How many planes contain a line and a point?		2000-08-30
		From Harold: How many planes contain each line and point? Answered by Harley Weston.
	Adriana's earnings		2000-08-28
		From Adriana: On Friday Adriana earns half as much as she did on Thursday. On Saturday she earns twice as much as she did on Thursday, if her total for 3 days is $63.00 how much did she earn each day? Answered by Penny Nom.
	Velocity of a pendulum		2000-08-28
		From Mekca: A pendulum hangs from the ceiling. as the pendulum swings, its distance,d cm, form one wall of the room depends on the number of seconds,t, since it was set in motion. assume that the equation for d as a function of t is: d=80+30cos3.14/3t, t>0. estimate the instantaneous rate of change of d at t=5 by finding the average rates for t=5 to 5.1, t=5 to 5.01, and t=5 to 5.001. Answered by Harley Weston.
	Solving an equation		2000-08-26
		From Patrick: My question is how would u do a problem like this.......... [2x-37] =15?....u have to solve it for absolute value equations....???? Answered by Harley Weston.
	Cubic yards and cubic feet		2000-08-26
		From Rhonda: have 2.47 cubic yards. what could the dimensions, in feet, be to equal this? Answered by Penny Nom.
	Subtracting fractions		2000-08-26
		From Sarah Stanczyk: how is this problem solved?? 3/ x+1 - 5/x ( 3 divided by x +1 subtracted by 5 divided by x) Answered by Penny Nom.
	The sum of the squares of 13 consecutive positive integers		2000-08-25
		From Wallace: Prove that it is not possible to have the sum of the squares of 13 consecutive positive integers be a square. Answered by Harley Weston.
	Three points on a line		2000-08-25
		From Casey: I am trying to find the slope and y-intercept of an equation. I have THREE x values and THREE y values. How do you do it? Help! Answered by Penny Nom.
	Three pattern questions		2000-08-22
		From Michael Rodriguez: I have 3 pattern questions that I need help answering, please. 6 and 7 = 42 2 and 5 = 10 4 and 8 = 8 5 and 9 = ? 7 and 5 = 1 9 and 12 = 3 10 and 15 = 5 12 and 16 = ? 1st = 1 3rd = DEF 10th = * 6th = ? Answered by Claude Tardif.
	Covering 1, 1/2, 1/3,...		2000-08-22
		From Wallace: Consider the points 1, 1/2, 1/3, ... on the real number line. You are given five small bars, all of length p, which are to be placed on the number line such that all points will be covered. What is the minimum value of p that will allow you to do this? Answered by Penny Nom.
	Slope		2000-08-19
		From John K. DePonte: My question is to why the variable "m" was chosen to represent the slope of a linear equation. I always told my class to think of "m" for "m"ountain slope. But what is the real reason for this? Answered by Penny Nom.
	Six typists		2000-08-19
		From Paula Duncan: If it takes a typist 4.5 hours to type 860 words, how many hours would it take 6 typist to do 16800 words? Answered by Penny Nom.
	Three consecutive odd integers		2000-08-18
		From Wallace: A six-digit integer XYXYXY, where X and Y are digits is equal to five times the product of three consecutive odd integers. Determine these three odd integers. Answered by Paul Betts.
	Two word problems		2000-08-16
		From Bridget: A whale's head is 72 inches long... its tail is as long as its head plus half the length of its body, and its body is half the entire length. How long is the whale? Also, An author published a book every two years. When the seventh one was published, the sum of the years of publication was 13,804. In what year was the author forst published? Answered by Penny Nom.
	Find the next term		2000-08-12
		From Ashley: 8,27,64 I need the next three numbers & I can't figure it out. I have worked on this all day. Answered by Penny Nom.
	Some trigonometry		2000-08-11
		From Angela: I have some PreCal questions. I am a student at the secondary level. I would be very grateful for your help. Solve the equation for theta (0 <= theta < 2pi). tan2(theta) = 3 I know sec2(theta) -1 = tan2(theta) . . . Answered by Harley Weston.
	A problem with a quadratic		2000-08-09
		From David Xiao: Find the value of a such that 4x2 + 4(a-2)x - 8a2 + 14a + 31 = 0 has real roots whose sum of squares is minimum. Answered by Harley Weston.
	PreCalculus		2000-08-09
		From Angela: Use absolute values to define the interval or pair of intervals on the real line. <--|--- |--- ]--- |--- |--- |--- [---| ---|--> 18 19 20 21 22 23 24 25 26 A car is moving at the rate of 50 miles per hour, and the diameter of its wheels is 2.5 feet. a) Find the number of revolutions per minute that the wheels are rotating. b) Find the angular speed of the wheels in radians per minute. Answered by Harley Weston.
	The angle of rotation		2000-08-03
		From Jay: I have the following information Given. (X1, Y1) Origional Point (X2, Y2) Origional Point After a Rotation (Xa, Xb) Center of Rotation What formula would I use to figure out the angle the point was rotated? Answered by Chris Fisher and Harley Weston.
	Area of a circle		2000-08-03
		From Larry: I know the formula is-- pi r squared--. For a circle 4 inches in diameter, do I multiply pi (3.1416) by the radius (2") then square the answer to that ie: 3.1416 X 2 squared or do I square the radius (2 X 2") then multiply by pi (3.1416) ?? Answered by Penny Nom.
	Graphing an inequality		2000-08-02
		From Lori: How do I find x and y and graph this problem 3x + y < 5 Answered by Penny Nom.
	Two linear systems		2000-08-01
		From A student: please help me with this homework question. 5/x + 6/y= 19/6 3/x + 4/y =2 hint: let a = 1/x and b = 1/y substitute these expressions into the system to find a and b. Then find x and y. This is a question I answered wrong on a test: solve the given system for x, y, and z. Express your solutions in terms of a, b, and c. Answered by Penny Nom.
	Making a paper cone		2000-07-30
		From John: The question of how to lay out & cut out of paper, cones came up. I would like the cone have : A base of 4 inches and height of 4 inches, 6 inches, 8 inches. Answered by Harley Weston.
	The circumference of a circle		2000-07-30
		From Not a student: An equalateral triangle is enclosed in a circle. The three corners touch the edges of the circle. One side of the triangle is 12. What is the circumference of the circle? Answered by Penny Nom.
	A semi-circle and a triangle		2000-07-28
		From Ben: A semi-circle and an isosceles triangle ABC have the same base AB and the same area. The equal angles in the triangle are BAC and CAB. I have to find the value of each of these angles. Answered by Harley Weston.
	LOG(LN(x)) = 1		2000-07-28
		From An algebra student: LET F(x)=LOG X AND G(x)= LN X. SOLVE (f *G)(x)= 1 SHOW COMPOSITION AND USE DEFINITION OF LOGS. Answered by Harley Weston.
	(mn + m + n)/(m^2 + n^2) = 1		2000-07-24
		From William: Find all pair of positive integers m and n such that mn + m + n divides m2 + n2 = 1. Answered by Peny Nom.
	An equation involving x to the x		2000-07-22
		From Joy Peter: I am joy, a teacher teaching Maths at the secondary level and while solving a sum came to this stage when i got xx (1 + log x) = 0, by which we can conclude that xx = 0 or 1 + log x = 0. If xx = 0, than what should be the value of x? I feel that the value of x should then be 0 (zero) but then how do I explain this to the students as we also know that anything to the power of 0 is 1 but here 0 raised to 0 is 1. If this is not defined then how do I explain this? Answered by Penny Nom.
	n! = 42(n-2)!		2000-07-21
		From Damon Bailey: Solve n! = 42(n-2)! Answered by Paul Betts.
	10,000!		2000-07-21
		From Lauren: Hi I was just wondering if you could tell me how many zeros are in 100,000! (factorial.) Answered by Denis Hanson.
	L'Hospital's Rule		2000-07-19
		From Dan Krymkowski: The limit of the following as x goes to infinity is 2*y. Y is a constant. lim 2*x*log(x/(x-y)) = 2*y Answered by Harley Weston.
	Completing a square		2000-07-10
		From Lexa Michaels: How do you complete a square? the textbook question is: x 4 + 64 Answered by Penny Nom.
	Patterning and Sequencing		2000-07-05
		From Michael Jellis: What would be the next two terms? 1.0,0.5,0.6,0.75,0.8,___,____ please explain!!! I am completely baffled and need all the help I can get! Answered by Claude Tardif.
	Five times a cube equals three times a fifth power		2000-07-05
		From Harman Chaudhry: Which is the smallest 10-digit number to be five times the cube of one number and also three times the fifth power of another? Answered by Penny Nom.
	Word addition		2000-07-05
		From Harman Chaudhry: What is the value of DISHES if SEE + THE + WAITER + WASHES = DISHES. In addition, I know there is a name for these types of problems--what are they actually called? Answered by Chris Fisher.
	Simplify 21+2[3z+5(3z+8)]		2000-07-02
		From Dennis Dyer: My daughter has a math problem that I can't help her with. The problem is 21+2[3z+5(3z+8)] I can get the answer 101 +36z but I can't show her the correct way to write it out. Would you please show the correct way to show her work... Answered by Penny Nom.
	A trig question		2000-07-01
		From Will: An open rectangular tank a units deep and b units wide holds water and is tilted so that the base BC makes an angle theta with the horizontal. When BC is returned to the horizontal, who that the depth of the water is (a squared) * cot theta div 2b units Answered by Harley Weston.
	Parallel tangents		2000-06-30
		From Ebony Indalecio: I need to prove the theroem: Tangents to a circle at the end points of a diameter are parallel. Answered by Walter Whiteley.
	Tiling a floor		2000-06-27
		From Carolyn Clarkston: A square tile measures 6 inches by 6 inches. What is the least number of tiles needed to cover a rectangular floor area of 9 feet by 12 feet? Answered by Walter Whiteley.
	Calculator and telephones keypads phones		2000-06-27
		From Thomas Smith and Veronica Yates-Riley: On a keyboard, why is the number "7" on the top of the keypad as opposed to the number "1" at the top a telephone keypad? Answered by Penny Nom.
	An Area		2000-06-26
		From Frank: Can you tell me what the sq. ft. are of and area measuring: __________58____________ | | | | | | | | | | 76 | 70 | | | | | |_____21________ | Answered by Harley Weston.
	Central Limit Theorem and Law of Large Numbers		2000-06-26
		From Jonathan Yam: The Central limit Theorem states that when sample size tends to infinity, the sample mean will be normally distributed. The Law of Large Number states that when sample size tends to infinity, the sample mean equals to population mean. Is the two statements contradictory? Answered by Paul Betts and Harley Weston.
	Cascade		2000-06-22
		From Peter Bengtsson: Can you help me find an equation for this correlation? 2*1+1 3*2+0 4*2+2 5*3+0 6*3+3 7*4+0 8*4+4 9*5+0 10*5+5 This is the way scores are calculated when you play the game Cascade. The more number of balls you manage to "click away", the better score you get. So, I wrote down lots of results for different amount of balls I clicked away. Clicking away one pair (two adjacent) of balls means 3 points. Clicking away three adjacent balls means 6 points. etc. You can see this from the list above. What I now want to do is to find an equation with only ONE unknown! Y= kn*X+c or something. Whereby I only know X, I can find Y. Answered by Penny Nom.
	A bar over a Roman numeral		2000-06-21
		From Charles Fontaine: Is there any significance to the bar placed over some Roman numerals? Answered by Penny Nom.
	Cairo tesselation and Archimedean duals		2000-06-21
		From Joyce DuVall: I am looking for a picture of the Cairo tesselation, and pictures of the Archimedean duals. Do you know of any good web sites or books? Answered by Penny Nom.
	Lines on an oscilloscope screen		2000-06-20
		From Janis Watson: What are the proper names for the vertical and horizontal lines on a graph? I am trying to explain an oscilloscope screen, and I don't know what to call these, except "vertical lines" and "horizontal lines." Answered by Penny Nom.
	The speed of light		2000-06-19
		From Benny Lau: I have a personal questions. In physics,if a person is running on a train, his relative speed on the ground will be the addition of the speed of train and the person. If u have a train inside another train and inside another train, so on...... can u reach the speed of light? It would need a very long distance. But if we make all the train travel in circles. Then we don't need that much distance. So can we achieve the speed of Light? Answered by Robert Coleman and Harley Weston.
	Numerator and denominator		2000-06-18
		From Maureen Beard: What is the origin of the terms numerator and denominater? Answered by Penny Nom.
	Names for large numbers		2000-06-16
		From Mireille Carthier: I am trying to find the common names (in English and French) for the big numbers as follows: English French 106 million million 109 billion milliard? 1012 trillion billion? 1015 ?? trillion? Thank you very much Answered by Claude Tardif and Harley Weston.
	A sequence		2000-06-16
		From Claire Hall: Can you find the formula for the pattern 4,12,24,40,60 Answered by AClaude Tardif.
	Simplifing		2000-06-15
		From Angie Herbert: My daughter is having problems with her algebra homework. She is a year 7 pupil at high school in the UK. She has been given homework on simplifying formulae and she doesn't understand how to do them. Here is an example of one of the questions : 9s+7t+5c+5s-3t can you help her to understand how to do these and perhaps me too. Answered by Penny Nom and Claude Tardif.
	A percentage question		2000-06-15
		From Michael Smith: I need a percentage for a business plan. How much is one-percent of two-hundred and thirty-nine million? Answered by Penny Nom.
	Rectangles and algebra		2000-06-13
		From Kirstin: A rectangle's length is 4 more than twice its width. The area of the rectangle is 336m squared. What is its length? Answered by Paul Betts and Penny Nom.
	Two problems		2000-06-12
		From Sharon: If f(4)=0 and f(6)=6, which of the following could represent f (x)? A. 2/3x-4 B. x+2 C. x-4 D. 3/2x+6 E. 3x-12 these are problems to study for a test so I need to know the answer and how it was solved! I have one more question If 180o < theta < 270o and tan theta = 4/3, then sin theta =? A. 5/4 B. -4/5 C. 3/5 D. 12/5 E. -3/5 Answered by Harley Weston.
	Projecting a line segment onto a plane		2000-06-08
		From Monica: What is the measure of the angle determined by a 14 inch segment and its projection into a plane if the length,in inches, of the projection into the plane is 7 inches? Answered by Penny Nom.
	Surface area of a contact lens		2000-06-06
		From Evie Contreras: I would like to know how to calculate the surface area of a contact lens with a radius of 7mm? I know that the area of a circle is pi R squared, but a contact lens has a dome. Answered by Harley Weston.
	8 Queens on a Chess Board		2000-06-06
		From Patrick McGarrity: In the classic puzzle where you put 8 Queens on a chess board and no queen can take any other queen, I was wondering if there was multiple solutions. Obviously there's the mirror and opposite images of the way I solved it, but I was wondering how many solutions there were, and if these solutions all followed a similar pattern? Answered by Claude Tardif.
	Divisors of 2000		2000-06-06
		From Amanda Semi: find the product of all the divisors of 2000 dog trainer time has 100m of fencing to enclose a rectangular exercise yard. One side of the yard can include all or part of one side of his building. iff the side of his building is 30 m, determine the maximum area he can enclose Answered by Claude Tardif.
	Problems		2000-06-06
		From Debbie Cummins: I am a Mum of a 12 yr.boy needing help with some math problems. I need not only the answers but how it is worked out. Both the leftmost digit & the rightmost digit of a 4 digit number N are equal to 1. When these digits are removed, the 2 digit number thus obtained is N div by 21 Find N. Find all 3 digit even numbers N such that 693xN is a perfect square, that is, 693x N = k x k where k is an integer. . . . Answered by Paul Betts and Claude Tardif.
	Writing in Math		2000-06-05
		From Laurel: How can I incorporate writing into my math curriculum? Answered by Penny Nom.
	A derivative problem		2000-06-04
		From Jeff Ellis: If F(x)=(4+x)(3+2x2)2(2+3x3)3, find F'(0) Answered by Harley Weston.
	Percents with mixed numbers		2000-06-04
		From Julie: How would you find the percent of 33 1/3 out of 90 by using fraction settup!I can do whole numbers but not mixed. This is how to do whole numbers say it was 33 of 90 33 x 90 = 2970 100 x 1 = 100 2970 divided by 100 the answer is 29.7 so how do you do it with a mixed number Answered by Penny Nom.
	Pi to 5 decimal places		2000-06-03
		From Emily: The question is find the value for pi to 5 decimal places???? Answered by Penny Nom.
	A centroid problem		2000-06-02
		From Kerstin: An isoceles triangle has sides measuring 13 cm, 13 cm, and 10 cm. Find the distance from the centroid to the vertex of a base angle. Answered by Harley Weston.
	4 Color map Theorem		2000-06-02
		From Rick Slen: I am challenging my students to find a map that can not be coloured using only 4 colours. I know that it is not possible, but one boy drew a map with a "country" totally surrounding all the others so of course it touched all other colours. How do I explain that this type of map is not permissable? Answered by Denis Hanson.
	1+4+9+16+...n^2 = n(n+1)(2n+1)/6		2000-06-01
		From Shamus O'Toole: How do you derive that for the series 1+4+9+16+25.. that S(n)=(n(n+1)(2n+1))/6 Answered by Penny Nom.
	Using the inverse sine function		2000-05-31
		From Nelson Rothermel: This has me completely baffled. I have to use the laws of sine or cosine to find the angles of a triangle when I have 3 sides, so I can't go 180-x-y when I have 2 angles. Now, I have a triangle with values of 3, 7, and 9. Here are the steps I used (A,B,C are angles; a,b,c are opposite sides): angle A (16.1951 degrees): cos-1*((b2+c2-a2)/(2*b*c)) angle B (40.6011 degrees): sin-1*(b*sin(A)/a) angle C (56.7962 degrees): sin-1*(c*sin(A)/a) If you notice, A+B+C does not equal 180. According to the book, A and B are correct, but C is supposed to be 123.2038 degrees. Why doesn't it work??? Answered by Harley Weston.
	Powers of i		2000-05-24
		From Paul Fieldhouse: What is the result of raising i to the googol power? is there a rule or pattern to raising i by increasing powers of 10? Answered by Penny Nom.
	Why does division start from the left?		2000-05-24
		From Salil Dave: Addition, subtraction and multiplications start with right most digit and proceed left, but division starts from left-most digits and goes right ... why? Answered by Harley Weston.
	A 100-gon		2000-05-24
		From Chris Mohr: What is a 100-gon called? Answered by Harley Weston.
	Angular velocity		2000-05-24
		From Ashley Milliman: The crankshaft of a particular automobile engine has an angular velocity of 1,500 rpm at 30 mph. The crankshaft pulley has a diameter of 10 cm, and it's attached to an air conditioner compressor pulley with a 7 cm diameter and an alternator pulley with a 5 cm diamter At what angular velocities do the compressor and alternator turn? . . . Answered by Harley Weston.
	The equation of a parabola		2000-05-22
		From Ian Forsyth: Given the points A(0,0) B(60,10) C(24,d) find the equation of the parabola. leave the equation in terms of x, y and d if the general form of a quadratic is y = ax2 + bx + c. Answered by Penny Nom.
	Calculus Research Questions		2000-05-22
		From William Wright: I am a Calculus Teacher, and me and my class ran into these two problems without solutions in my manual, we got answers, but are unable to check them. If anyone gets this email and can respond to this with the solutions it be greatly appreciated. . . . Answered by Harley Weston.
	Adjacent Angles		2000-05-21
		From Katherine Keys: Can a straight angle be an adjacent angle to another angle? Answered by Chris Fisher.
	Volume of a sphere		2000-05-21
		From Kevin Partridge: Does anyone have a way to physically demonstrate how to explain the volume formula for a sphere? Or perhaps how to derive the formula without calculus? Answered by Harley Weston.
	The pythagorean theorem		2000-05-19
		From Lauren Fitzgerald: how do you find the length of th hipotnuse( or however you spell that word). i understand you have to add the two sides. but when i do add i always end up with this way off answer. i donot understand at all. Answered by Paul Betts.
	The square root of -1		2000-05-19
		From Gary: i am not a student i am just some one that heard something and i can't be sure on the answer...my ? is what is the square root of -1? i think it is -1 but not sure can you let me know please thank you Answered by Harley Weston.
	A conic in standard form		2000-05-18
		From Tara McConkey: Im havign trouble converting the following conic to standard form, i know that the conic is a hyperbola but that is all 16x2-9y2-160x-18y+247=0 Answered by Harley Weston.
	Radioactive decay		2000-05-18
		From Catherine Sullivan: Please help me with the following: The radioactive isotope carbon-14 is present in small quantities in all life forms, and it is constantly replenished until the organism dies, after which it decays to carbon-12 at a rate proportional to the amount of C-14 present, with a half life of 5730 years. Suppose C(t) is the amount of C-14 at time t. Find the value of the constant k in the differential equation: C'=-kC In 1988 3 teams of scientists found that the Shroud of Turin, which was reputed to be the burial cloth of Jesus, contained 91% of the amount of C-14 contained in freshly made cloth of the same material. How old is the Shroud according to the data? Answered by Harley Weston.
	Graphing a linear function		2000-05-17
		From Chelsea: I need help with grahing linear functions.If you could e-mail me back the basics and how tos I would be much appriciative. Answered by Penny Nom.
	The number of seats in an auditorium		2000-05-16
		From David Evaska: There are 10 students in the first row of seats in an auditorium 12 in the second 14 in the third and 2 additional in each seat. The total number of rows is 40. I know the answer is 1960 can you please show me the formula step by step. Answered by Penny Nom.
	Six letter words		2000-05-15
		From Karl Freitag: An anthroplogist discovers an isolated tribe whose written alphabet contains only six letters (call the letters A,B,C,D,E, and F). The tribe has a taboo against using the same letter twice in the same word. It is never done. If each different sequence of letters constitutes a different word in the language, what is the maximum number of six-letter words that the language can employ? Answered by Penny Nom.
	A trigonmetric identity		2000-05-15
		From Caitlin: My name is Caitlin and my question is from 11th grade math and I'm a student my question is I need to solve this identity : cos x csc x - sin x sec x = 2 cot 2x Answered by Paul Betts.
	Multiplying fractions		2000-05-14
		From A student: 75/2 x 1/100 = 3/8 Please show how to came up with the answer? Answered by Penny Nom.
	A matrix equation		2000-05-14
		From A student: Right now, we are dealing with matrices and we are supposed to solve the following problem on our graphing-calculators: 2a+3b-4c+d=20 a-2b+3c-5d=-14 3a+4b-2c+3d=19 5a-b+6c+4d=-5 Answered by Penny Nom.
	Subtracting polynomials		2000-05-13
		From Teresa: I am suppose to subtract the lower polynomial from the one above it. -3a+11b+2f -3a- 6b+8f ________________ Answered by Penny Nom.
	4x - [2x -(3x - 2)] = 13		2000-05-13
		From Teresa: I need to find the following equation. 4x - [2x -(3x - 2)] = 13 Answered by Penny Nom.
	Reflection off a sphere		2000-05-12
		From Mark Adami: Given two points P,E and a sphere. Find a point on the sphere, T, so that a line from P that bounces off the sphere at T goes through point E. Answered by Chris Fisher and Harley Weston.
	Solve 2sin 3x-1=0		2000-05-11
		From Cynthia: How would you solve 2sin 3x-1=0? I don't know what to do with the 3. Answered by Penny Nom.
	The units digit of 3 to the 58th power		2000-05-10
		From Kylie Mcalpine: the questions we have been asked are what is the units digit of the following: a) 358 b) 2358 c) 1731 and the harder question of: what is the units digit of the following sum: 13841 + 17508 + 24617 = ??????? Answered by Paul Betts and Penny Nom.
	Odds and combinations		2000-05-10
		From Lucy: If the odds are 1/15 of winning, what is the probability? if c 5! 3! How does it equal 10? Answered by Harley Weston.
	The Village of Truth		2000-05-10
		From Sean Pearson: Our teacher gave us a logic problem involving two villages: the village of truth, and the village of lies. The problem is in asking two guards the right question to gain entrance to the fenced compound the villages are in without being shot. Have you heard of this problem ? Answered by Harley Weston.
	Trig functions		2000-05-09
		From Melissa: Find all solutions in the interval (0,2pi) 2cos2x-3cosx-4=0 Answered by Paul Betts and Harley Weston.
	Supplementary angles		2000-05-09
		From Suzanne: We know that: Supplementary angles are two angles whose sum equals 180 degrees and complementary angles are two angles whose sum equals 90 degrees. Are supplementary and complementary angles necessarily adjacent? or can they be non-adjacent? Answered by Chris Fisher.
	Looking for a pattern		2000-05-08
		From Laura: Yesterday, me teacher stumped me with a question. He talked to us about square units. He told us an area of 1 square unit produces 1 shape, an area of 2 sq.units produces 1 shape, an area of 3 sq.units produces 2 different shapes, an area of four square units produces 5 different shapes, and an area od five sq.units produces 12 different shapes. He left us there. He said we had to find how many different shapes an area of 1 sq. unit produces through how many different shapes an area of 15 sq.units produces. He said we could complete this "chart" by finding an equation. But, I can't find the equation. I think it may be a quadratic of some sort. My teacher told us to use the area(in sq.units) as X and the # of different shapes produced as Y. Now, what really is stumping me is I would have to have an equation so when X is Y, Y is 1 and when X is 2, Y is 1. I have also tried to see if I can complete a patter or something. The pattern I saw was 1,1,2,5,12. I can't make much sense of that pattern. Answered by Penny Nom.
	Parallel and perpendicular lines		2000-05-08
		From Jimmy Lumpkins: Need a method for solving the following problem: Find the equation of a line through point P that is parallel or perpendicular to another line. Answered by Paul Betts.
	Related Rates		2000-05-07
		From Derek: How can you show that if the volume of a balloon is decreasing at a rate proportional to its surface area, the radius of the balloon is shrinking at a constant rate. Answered by Harley Weston.
	Probability and odds		2000-05-05
		From Leah: The chances of rain on friday, saturday, and sunday are 20%, 30%, and 50% respectively. what are the odds it will rain all three days? Answered by Harley Weston.
	Finding a formula		2000-05-05
		From Erica Hildebrandt: If a farmer has a field and his plots are laid out in the following grid where each # represents a plot: 4 5 12 13 20 3 6 11 14 19 2 7 10 15 18 1 8 9 16 17 Of course the plot numbers aren't meaningful as I have described above. In fact they may not be numbers at all. The only constants I have are the total number of rows and columns. Using the total number of rows and columns and my current position row and column, how can I write a formula that tells me column 3 row 3 = 10, column 4 row 2 = 14, etc. I can see the pattern but can't quite get the formula. I believe I will need 2 different formulas one for even and one for odd rows. Answered by Paul Betts and Penny Nom.
	An improper integral		2000-05-04
		From A high school senior: Hi, I am a high school senior and I need help stugying for a final. I am stuck on one of the questions on my review sheet. Does the improper integral from 5 to infinity of (38/97)x converge or diverge? If it converges I also need to know how to find the approximate value accurate to .01 of its actual value. Answered by Harley Weston.
	sin(7pi/12)		2000-05-04
		From Kristel: What is the exact value of sin 7pi/12? Answered by Chris Fisher and Paul Betts.
	Thearcius Functionius		2000-05-03
		From Kevin Palmer: With the Olympics fast approaching the networks are focusing in ona new and exciting runner from Greece. Thearcius Functionius has astounded the world with his speed. He has already established new world records in the 100 meter dash and looks to improve on those times at the 2000 Summer Olympics. Thearcius Functionius stands a full 2 meters tall and the networks plan on placing a camera on the ground at some location after the finish line(in his lane) to film the history making run. The camera is set to film him from his knees(0.5 meters up from the ground) to 0.5 meters above his head at the instant he finishes the race. This is a total distance of two meters(the distance shown by the camera's lens). Answered by Harley Weston.
	An indefinite integral		2000-05-03
		From Bonnie Null: I am to find the indefinite integral of: (ex - e-x)2 dx Answered by Claude Tardif.
	Mary Fairfax Greig Somerville		2000-05-03
		From Joshua Garrett: I'm giving a report in class on her life. Could i recieve some sort of information about her. thank you Answered by Claude Tardif.
	Why is 1/4 larger than 1/5?		2000-05-02
		From Sherry: I have to do a math project for my teacher education class. The question that I am working on is why is 1/4 bigger than 1/5. Answered by Paul Betts, Claude Tardif and Penny Nom.
	Minimizing the metal in a can		2000-05-02
		From May Thin Zar Han: A can is to be made to hold 1 L of oil. Find the dimensions that will minimize the cost of the metal to manufacture the can. Answered by Harley Weston.
	Matrices Information		2000-05-02
		From William Avery: I am an OAC student at Governor Simcoe Secondary School in St. Catharines Ontario. Today at school we were handed an independent study project by our Finite teacher. This assignment is based on Matrices, it involves performing some simple matrix calculations, but also involves a written section. This written section asks for the following: . . . Answered by Marley Weston.
	Area of an ellipse		2000-05-02
		From Kaushal Shah: How do I Calculate the area of a ellipse known the length of any related thing. Example, suppose if I know the length of latus rectum, major&minor axis etc. Answered by Walter Whiteley.
	Two calculus problems		2000-05-01
		From Kaushal Shah: How Do WE Integrate the following Functions, Integral xtanx dx How was natural base "e" discovered and why e=2.7....... Answered by Claude Tardif.
	Fractals		2000-04-29
		From Rachel Maginn: What are Fractals? I am doing a research project. Any information would be great. I need to know the history behind fractals, and how they are used. I would like some examples like the snowflake and a fractal tree. Any other examples would be appriciated greatly. Answered by Harley Weston.
	What percent is one fraction of another fraction?		2000-04-29
		From A student in grade 4: What is the method for finding out what percent one fraction is of another fraction. For instance 4/5 is what percent of 1/9? Answered by Penny Nom.
	Monica's geometry problem		2000-04-27
		From Monica: Given: ABCD is a square; AX is perpendicular to BY Prove: Angle 1 is congruent to Angle 3 Answered by Chris Fisher.
	Graphing cube roots		2000-04-27
		From Heather Jones: What do the graphs of cube roots look like? Answered by Walter Whiteley.
	Searching for socks		2000-04-26
		From Luther Jackson: There are 10 red socks and 10 blue socks in a drawer. Aside from their color the are identical. All of the socks in the drawer are mixed up. If the room was pitch black, How many socks would you need to pull out of the drawer to be certain that you have a pair that matches? Why? Answered by Penny Nom.
	Paying with silver		2000-04-26
		From Luther Jackson: A silver prospector is unable to pay his March rent in advance. He owned a bar of pure silver, 31 inches long, so he made the following arrangement with his landlady. He would cut the bar, he said into smaller pieces. On the first day of March he would give her and inch of the bar, and on each succeeding day he would add another inch to her amount of silver. She would keep this silver as security. At the end of the month, when the prospector expected to be able to pay his rent in full, she would return the pieces to him. . . . Answered by Claude Tardif and Penny Nom.
	The weight of a watermelon		2000-04-25
		From Lori Speir: If I have a 100 pound watermelon and it is 99% water. If it sits out in the sun all day and is now only 98% water what does it weigh now? Answered by Penny Nom.
	An expected value		2000-04-24
		From Carl Pride: Suppose that in a statistics class of size 23, each student has a probability of passing of 73 percent. sample: What is the expected number of students who will pass?? Answered by Harley Weston.
	Conversions		2000-04-23
		From Tara: 750 lbs = ___ tons How do I figure this out!? I know that 1 ton is 2000 lbs, how do I figure out this answer? Answered by Penny Nom.
	Adding fractions		2000-04-23
		From A grade 6 student: In adding fractions, how do I rewrite the fractions so that the denominators are equal? The problem is 3/4 + 1/6 = The other problem is 11/18 + 4/9 = Answered by Penny Nom.
	A colony of bacteria		2000-04-22
		From Nicci Demmin: Suppose that the bacteria in a colony can grow unchecked, by the law of exponential change. The colony starts with one bacterium and doubles every half hour. How many bacteria will the colony contain at the end of 50 hours? Answered by Penny Nom.
	Side length of an octagon		2000-04-22
		From Unknown: If I have an octagon that is 12 feet across (side to opposite side) how can I find the length of the sides? Answered by Harley Weston.
	Two gross minus two score		2000-04-20
		From Georgie: What is two gross minus two score? Answered by Chris Fisher.
	Circumference = Area		2000-04-19
		From Scot George: The area and circumference of a circle has the same measurement. Find the radius. Answered by Chris Fisher.
	Chisanbop		2000-04-19
		From Steven D. Edmonds: I once heard about a manual counting method which when learned at an early age allowed one to be able to perform large calculations manually. I believe that name of the method (phonetically) was "chisenbok". Answered by Harley Weston.
	Question regarding Combinations and permutations		2000-04-19
		From Paul Stoner: I am a programmer and I have a quick question. I have 5 criteria which will either be true or false. If a criterion is true it returns its ordinal representation, if false it returns 0. I then combine these results to determine where to go in my program. My question is: How can I figure out the number of combinations I will need? Answered by Patrick Maidorn.
	Math in various careers		2000-04-18
		From Jennifer Jones: I am a Fifth grade student researching how math is used in various careers. What kind of math is used in your career? How do you use math? Answered by Harley Weston.
	Borrowing		2000-04-17
		From A college student: How would you explain borrowing to an elementary school student? Answered by Penny Nom.
	Factoring trinomials that are squared		2000-04-17
		From A student: I have a question that I really need an answer to. I need help with factoring trinomials that are squared. Answered by Penny Nom.
	Uniting algebra and geometry		2000-04-16
		From Beth: Who is the mathmatician that united algebra and geometry??? Answered by Claude Tardif.
	Finding a Quadratic Equation given the roots		2000-04-16
		From A secondary student: How do I find the equation for the quadratic with roots at 2-i and its complex conjugate? Answered by Harley Weston.
	Sample variance		2000-04-16
		From Jonathan Freeman: I was just reading your article entitled "A Note on Standard Deviation" I'm now teaching a unit on s.d. and my students were wondering why one uses a denominator of n for a population and n-1 for a sample. I saw in your article that this is because "[the quantity] tends to underestimate sigma... and other technical reasons." To which my students again asked... "Why?" Could you please elaborate a bit on the "other technical reasons" perhaps in terms a high school senior (or their teacher...) could understand? Answered by Harley Weston.
	All the roots of x^6 - 64		2000-04-15
		From Dakota: Find ALL zeros of P(x) = x 6 - 64 Answered by Walter Whiteley.
	The area of a triangle using calculus		2000-04-15
		From Todd Bowie: Hi, I am not a student but am reviewing calculus for an upcoming interview. I would like to know how to derive the area of a triangle using calculus. Thanks! Answered by Patrick Maidorn.
	Rounding		2000-04-15
		From Tawana Brown: I was uncertain as to whether a number such as 85.25 rounding to the nearest tenth would be 85.3 or 85.2. I thought I had heard somewhere that if 5 is the last number that you don't round up. But I have also heard that anything 5 and above you do round up. It's been awhile since I've done rounding, so I need a refresher course. Answered by Walter Whiteley and Harley Weston.
	Job outlook		2000-04-12
		From Shelby Faust: what is the future demand, in numbers, of a secondary mathematics teacher? what are the projected costs for this career? what technology skills will be needed for this career? Answered by Walter Whiteley.
	Logs		2000-04-12
		From Jessica: Write as a single log 3ln x - 2ln(y+e) + 5ln(x-12) - 4ln y Answered by Harley Weston.
	Infinite sets		2000-04-12
		From Brian Provost: Here's the deal: There are an infinite amount of integers (1,2,3...). Agreed? There are an infinite amount of even integers, too (2,4,6...). Agreed? By convention, infinity equals infinity. Yet common sense tells us there are obviously more integers than there are even integers. Prove this to be true mathematically. Answered by Harley Weston.
	Natural numbers		2000-04-12
		From Sara: What is a natural number??? Answered by Penny Nom.
	Estimates		2000-04-11
		From Sue Jordan: I am looking for examples of estimates for underestimating and overestimating. When would you do each one. For my child age 11 6th grade. Answered by Penny Nom.
	Geometric sequences		2000-04-11
		From Jodie: I am in a grade ten principles class and was taught how to do geometric sequences and series but no one in my class understood what we were taught. Our teacher is one of few to use the new curriculum which used to be the grade twelve curriculum. Could you please explain to me how to do geometric sequences and how to find the different terms and sums. Thank you very much! Answered by Harley Weston.
	Magic triangles		2000-04-11
		From Sandy: My tutoring student brought math homework today in the form of a "magic triangle". There are three spaces along each side for missing numbers. The sums of the numbers along each of the 3 sides should be the same. Use the numbers 4 through 9. Don't use any number more than once. The sum of the numbers on each side should be 20. What is the logic behind solving a problem of this kind? Answered by Claude Tardif and Harley Weston.
	White and blue paint		2000-04-09
		From Lauren Emerson: A truck full of cans of blue and white paint flips over on the road. There are dots of blue and white paint everywhere. Prove that two dots of the same color paint are exactly pi feet apart. Answered by Penny Nom.
	How many zeros?		2000-04-09
		From Greg Potts: The natural numbers 1 to 25 are multiplied together (1 x 2 x 3x..24 x 25). How many zeros are there in the product of this multiplication? a)6 b)7 c)5 d)10 or e)4? Answered by Harley Weston.
	2^32 + 1		2000-04-08
		From Un Etudiant: 232 +1 can be divided by 641 , why? Answered by Claude Tradif.
	Star-multiplication		2000-04-07
		From Greg Potts: I have this question to answer and I don't know where to start. 1*9=0, 9*8=72 and 2*8=9, then 9*9 =? Answered by Penny Nom.
	42% of 70		2000-04-07
		From Nikkie: What is 42% of 70? Answered by Penny Nom.
	Surface area of a cylinder		2000-04-07
		From Jim Campbell: I am going to cover the outside of a shaft with some material. How do I figure the square inches of the outside surface of the shaft? Shaft is 6" in diameter and 24" long Answered by Harley Weston.
	History of a meter		2000-04-07
		From Jarod Fischer: The length of a meter has been determined in three different ways. The first and original way was determined in 1798. The second way was determined in 1960. The third and current way was determined in 1983. What were the three ways and why were the first two abandoned? Answered by Harley Weston.
	Lining a cone		2000-04-06
		From Jim Campbell: I am not a student, I am trying to solve a business problem. The question. If I want to put a lining in a chute that is cone shaped, how do I calculate the size steel plate I need to do that. The cone is 10' in diameter at the top and has a 20" hole at the bottom. The total height of the chute is 8'. Answered by Harley Weston.
	Why are equivalent fractions equal?		2000-04-05
		From An elementary student: What is the mathematical reason equivalent fractions are equal? Answered by Penny Nom.
	y = x^x^x^x...		2000-04-05
		From Michael Hackman: Find the derivative of: y = x^x^x^x... on to infinity. Answered by Claude Tardif.
	How many grams are in 1 ounce?		2000-04-04
		From Kathy G: How many grams are in 1 ounce? Answered by Penny Nom.
	Manipulatives		2000-04-04
		From Jodi Stuker: I am a student looking for a good lesson plan using manipulatives to teach multiplication to LD students. They are currently functioning on approximately 3rd grade level in math but are age 12-14. Answered by Penny Nom.
	Nim		2000-04-04
		From Sandy Daniel: Could you please give me any information on this Math Fair topic? Answered by Claude Tardif.
	The square root of 3		2000-04-04
		From Mr. William: Prove that root 3 is irrational Answered by Harley Weston.
	The side length ratios of some triangles		2000-04-04
		From Alexis Lockwood: I am doing a project for my Math 30B class regarding the side length ratios of 45-45-90 degree and 30-60-90 degree triangles. I would really appreciate any assistance in answering the following questions, or even direction to an appropriate web site or resource on the matter. Answered by Harley Weston.
	Interest compounded daily		2000-04-03
		From Debbie Bracken: How do I figure interest that is compounded daily? 8% compounded daily. Answered by Penny nom.
	Why a Right angle?		2000-04-03
		From Joseph Mizerek: I was wondering why a 90 degree angle is called a Right angle. I mean why isn't called a left angle. Answered by Haragauri Gupta.
	Wholesale price		2000-04-02
		From Lynda Bintz: If a product is priced at $4.99 and is marked up 40% how do I calculate the wholesale price? Answered by Penny Nom.
	Running Through a Train Tunnel		2000-04-01
		From Eugene Chan: A man is running through a train tunnel. When he is 2/3 of the way through, he hears a train that is approaching the tunnel from behind him at a speed of 60 mph. Whether he runs ahead or back, he will reach an end of the tunnel at the same time the train reaches that end. At what rate, in miles per hour, is he running? (Assume he runs at a constant rate.) I think the answer (12 mph) is wrong. Also, I believe it should read 1/3 of the way through, but don't know how to prove it. Could you come up with some way to prove it, please? I would really appreciate it. Answered by Penny Nom.
	Filling a hole		2000-04-01
		From John McNeill: I have an area 20 feet long and 12 feet wide It starts out at a depth of 4 inches and ends up at 0 inches. How much sand do I need to fill the excavation. Answered by Penny Nom.
	Symmetric Primes		2000-04-01
		From Marlene Moore: Hi...Im in 9th grade and am having a hard time figuring out symmetric primes. Heres the problem: Find two pairs of symmetric primes of 20. Symmetric primes of 15? Answered by Claude Tardif.
	Careers after a math degree		2000-03-31
		From Jeanne Hyer: What type of careers can a person have with a math degree, and what is the closest thing that you have to an undergraduate degree in financial mathematics? (Administration, math, actuarial science, etc.) Answered by Harley Weston.
	Word problems		2000-03-31
		From Amy: Question: a north bound train left at noon. four hours later a south bound train left the same station. at 5 o'clook they were 160 miles apart. what was the rate of both if the north bound train was going 20 miles faster than the other one. clark's final exam was given 5 times the weight of the weight of a weekly test. the avgerage of 15 weekly test was 91. the overall weighted average was 85. what did he make on the final. Answered by Penny Nom.
	Hats, jackets and gloves		2000-03-30
		From Max: Find the one that does not belong 66 333 99 111 88 also if you have 3 hats and 3 jackets and 3 gloves, how many different combinations of a hat and a jacket and gloves can you wear? Answered by Claude Tardif and Penny Nom.
	Riemann sums		2000-03-30
		From Joshua D. Parham: If n is a positive integer, then lim (1/n)[1/(1+1/n) + 1/(1+(2/n) + ... + 1/(1+n/n)] n->infinity can be expressed as the integral from 1 to 2 of 1/x dx Answered by Penny Nom.
	Making fruit salad		2000-03-29
		From A grade 5 student: Miss.Muffet males a fruit salad by adding 31/2 pounds of grapes and 4 1/4 pounds of apples to every 2 1/4 pounds of melon. How many pounds of grapes does she use in 50 pounds of fruit salad? Answered by Claude Tardif.
	The world of percentage. Price tags everywhere		2000-03-27
		From Lydia: I know there is a formula to be utilized for finding the percentage of a number, like most math. You just simply need to remember the formula for finding the number. Please put me on the path. How does one figure out 10% or 15% of a total number asked? Say... 120 Reverse: 15 is what percent of 120, I know the answer should be the same but how is the formula applied? Answered by Harley Weston.
	Taxis in Chicago		2000-03-27
		From A high school studenthigh school student: Suppose that taxis pick up and deliver passengers in Chicago, which is divided into three zones. Records kept by the drivers show that of the passengers picked up in Zone 1, 50% are taken to a destination in Zone 1, 40% to Zone 2, and 10% to Zone 3. OF the passengers picked up in Zone 2, 40% go to Zone 1, 30% to Zone 2, and 30% to Zone 3. Of the passengers picked up in Zone 3, 20% go to Zone 1, 60% to Zone 2 and 20% to Zone 3. Suppose that at the beginning of the day, 600 of the taxis are in Zone 1, 100 in Zone 2, and 300 in Zone 3. What is the distribution of taxis in the various zones after all have had two riders? Answered by Harley Weston.
	Division		2000-03-26
		From Kelly Allen: My 8 year old daughter had 12 bracelets which she arranged into 4 piles of 3. Did she divide 12 by 3 or by 4? Most people I've asked can only offer an opinion. What I'm looking for is a definitive answer, if there is one. My husband says the number of sets is the answer: 12 divided by 3 = 4 Most others I've asked said that the amount in each set is the answer: 12 divided by 4 = 3 Answered by Harley Weston.
	Divisibility by 3		2000-03-24
		From Pat Walsh: W hy does it work when you add the digits of a number then divid by three to see if the number is divisible by three Answered by Penny Nom.
	Increasing the weight		2000-03-23
		From Lee Millard: A weight of dimension a, b is to have its weight increased by w% by bolting plates of the same material along the top and one side (but not at both ends). The top plate and side plate have the thickness, x. Find the thickness of the plates for a given weight increase of w%. Answered by Penny Nom.
	Sylvester's Problem		2000-03-23
		From Sheryl Webb: I am trying to find a proof of the theorem: Given n points in a plane, there is a line that contains exactly two points. Answered by Chris Fisher.
	A parabola problem		2000-03-23
		From Morin: I need to prove that if parabola x2=4py has a chord (not necessarily a focal chord) intersecting it at points A and B, with tangents to the parabola at points A and B that intersect at C, then a line drawn through C and the midpoint of the chord M is parallel to the y-axis. Further, prove that the point D where this line intersects the parabola is the midpoint of line CM. Answered by Penny Nom.
	Reflex angles		2000-03-22
		From D. Reed: What is the name of an angle that exceeds 180 degrees? Answered by Penny Nom.
	Rule of 78		2000-03-22
		From Dan Baumgarten: Can you explain the rule of 78 and the reverse rule of 78? Thanks. Answered by Claude Tardif.
	Surface area of a sphere		2000-03-22
		From Gina Wilkie: How can I demonstrate to my middle school students the reason for the formula for the surface area of a sphere? Answered by Walter Whiteley and Chris Fisher.
	I am in lowest terms.		2000-03-21
		From Travis Fox: I am in lowest terms. When you double my numerator and my denominator the result is 10/15. Answered by Penny Nom.
	Compounding continuously		2000-03-21
		From Gina: You deposit $1500 in an account that pays 6.5% annual interest, compounded continuously. Find the balance after 10 years. I'm not sure what to do with the "compounded continuously" part. Answered by Penny Nom.
	Binomial coefficients		2000-03-21
		From Howard Lutz: How do you find each successive numerical term in this equation y+dy=(x+dx)5 =x5+5*x4dx+10*x3(dx)2+10*x^2(dx)3+5*x(dx)4+(dx)5 I would appreciate an explanation of the method to find the numeric coefficient in a binomial expansion Answered by Penny Nom.
	A system of equations in five unknowns		2000-03-20
		From Will: I have been having some problem with the following question for some time. I would appreciate any help on solving the problem or a solution. Q: Assume that a system of equations in the unknowns x1, x2, x3, x4 and x5 when converted to row echelon form gives . . . Answered by Penny Nom.
	root(-1)* root(-1)		2000-03-20
		From Michael Moran: i squared = -1 but i squared = root(-1)* root(-1) = root( -1*-1) = root(1) = 1 -1 doesn't = 1 can you help me with my question Answered by Claude Tardif.
	Travelling from A to B		2000-03-20
		From Matt: A car is traveling from point A to point B. Point A and point B are 30 miles apart. A car travels 30 miles an hour from point A to point B and then goes back to point A. How fast does the car have to go back to average 60 miles an hour? Answered by Claude Tardif.
	Six digit numbers using 1,2,5,6,7, and 9		2000-03-20
		From Rachel: How many different six-digit numbers can you make using the digits 1,2,5,6,7, and 9? How many of these six digit numbers are divisible by six? Answered by Claude Tardif and Denis Hanson.
	A quantitative methods course		2000-03-19
		From Mark Haberman: Question: Last semester, the grade distribution in a quantitative methods course had the following distribution: 10% A, 25% B, 35% C, 10% D, and 15% W (withdrew). If this grade distribution does not change this semester, what is the probability that a randomly selected student will make at least a D? If this grade distribution does not change this semester, what is the probability that a randomly selected student will fail the course? If this grade distribution does not change this semester, what is the probability that a randomly selected student who finished that course (did not withdraw) made a grade of D or better? Answered by Harley Weston.
	The Terror Run		2000-03-18
		From Danny Mclean: A fairground's most popular attraction is a roller coaster ride known as the Terror Run. One stretch of track is called the Missile Path and is in the form of a parabolic curve. B is 180m horizontally from A and the highest point of the curve is 100m above A and B. A.. The owner works out a quadratic expression to describe the Missile Path. What is the expression He found? B.. A safety Engineer examined the structure and observed that points A and B were likely to be damaged due to the steepness of the Missile path near these points. The owner can see no way to make the Missile path less steep near A and B and to keep the height of the ride the same. HOW CAN IT BE DONE? Answered by Harley Weston.
	Four questions		2000-03-17
		From Ibrahim Bin kasmin: What is a hexahedron?(please show a picture of a hexahedron). How do we make a cube out of three pyramids?(show me the picture). How do we find the approximate perimeter and area of a hibiscus leaf? What is a Pascal triangle? Answered by Penny Nom.
	The Kennedy Pep Club		2000-03-17
		From David Grimmer: The Kennedy Pep Club rented a bus to take all of its members to a baseball game. The cost per person was to be $18.00. However, those making the trip had to pay $24.00 each because 10 members cancelled at the last minute. How many pep club members took the bus to the game? Answered by Penny Nom.
	Completing a sequence		2000-03-17
		From David Grimmer: Complete the following sequence so that, after the first two terms, each successive term is the average of all the preceding terms. 20__ __ 28 __ __ Answered by Penny Nom.
	1000 percent		2000-03-17
		From Matt Stevenson: If one invests $4000.00 and makes 1000% on the investment would he/she have $40,000.00? Could one figure this by: $4000.00 * 10.0 = $40,000.00? So is 10 times a number the same as 1000%? Would 100 times a number be the same as 10,000%? Answered by Penny Nom.
	Division		2000-03-16
		From Charday: What is the easiest way to calculate the least number that can be divided evenly by all the numbers from 1 to 10. Answered by Penny Nom.
	Induction		2000-03-16
		From William Tsang: I am trying to prove a induction question Sigam r=1 n (2r -1)cube = n square (2 n square - 1) Answered by Harley Weston.
	Functions that satisfy f' = f		2000-03-16
		From Kevin Palmer: Recently my calculus teacher asked his students to try and find any functions whose derivatives where the exact same as the original function. The only function then I have determined that statement to be accurate in is all the natural exponential functions. Ex. f(x) = ex, f'(x) = ex If possible could you please email me all the functions that you can find in which the original function and its derivative is identical. Answered by Claude Tardif.
	Putting in a pool		2000-03-16
		From Katie: If your digging a hole for a pool and the pool is: Length= 11m Width= 6m Sallow Depth= 1.1m graduating to 'Deep' Depth= 1.8m What is the volume of soil that will be taken out? And if a bobcat can excavate and remove 10m3 (qubed) of soil an hour how long will it take him to excavate the soil. Answered by Penny Nom.
	Geometrical solids		2000-03-15
		From Sarah: What geometrical solid has 8 edges and 5 vertices? What geometrical solid has 12 edges that are all the same length? Answered by Walter Whiteley.
	Rationals, irrationals and integers		2000-03-14
		From Erin McKeon: Why does the letter J represent the set of integers, the letter Q represent a set of rational numbers and the letter P represent a set of irrational numbers? What do each of these letters stand for? Answered by Harley Weston.
	Eligibility in a contest		2000-03-14
		From Ken Rabley: Hi, hoping you can help. Dispute among co-workers. Tell me, what is the correct answer to the following question: -1936 + (2406/4812) x (4756 - 3256) + 1250 Seems this is the question for eligibility in a contest...We have come up with various solutions, all which may be correct. Answered by Penny Nom.
	Characteristic of a logarithm		2000-03-14
		From Andrew Strauss: What is the characteristic of log base 18 of 1980 ? Answered by Harley Weston.
	Two problems		2000-03-14
		From Teresa Bostic : A man's age at death was 1/29 of the year of his birth. How old was he in 1949? At a contest, 2 persons were asked their ages. Then to test their ability mathematically, they were asked to give the ages together. One gave 44 and the other gave 1280. The first had subtracted one age from another, and the second had multiplied the two together. What were their ages? Answered by Penny Nom.
	An integer max-min problem		2000-03-13
		From Paul Servic: Maximize Q = xy 2 where x and y are positive integers such that x + y 2 = 4 Answered by Penny Nom.
	A trogonometry problem		2000-03-12
		From A student: Find all values of X in the interval 0 degrees <= x < 360 degrees that satisfy the equation 2sin x - cos 2x = 0. Answered by Harley Weston.
	Maximize		2000-03-12
		From Tara Doucet: My question is Maximize Q=xy^2 (y is to the exponent 2) where x and y are positive integers such that x + y^2 ( y is to the exponent 2)=4 Answered by Harley Weston.
	An equilateral triangle in a circle		2000-03-11
		From Michael Setlik: An equilateral triangle is drawn within a circle such that all three points of the triangle just touch the inside of the circle. Given the diameter of the cicle as six inches what is the length of the sides of the triangle? Answered by Harley Weston.
	Simultaneous equations		2000-03-11
		From Laura Molck: My name is Laura Molck and I am in Year 11 in Australia. Please help me with the following. I know that they are all simultaneous equations which I can do but I have trouble with the formulae to work the equations. Can you please help!! 1. A tent manufacturer produces 2 models, Outback and Bushwalker. From earlier sales records it is known that 20% more of the Outback model is sold than the Bushwalker. A profit of $200 is made on each Outback sold, but $350 is made on each Bushwalker. If during the next year a profit of $177,000 is planned how many of each model must be sold? Answered by Penny Nom.
	Completing the square		2000-03-11
		From Sandra: How do i complete the square and leave in simple radical form? x squared + 18x - 17=0 Answered by Penny Nom.
	Congruent parts of congruent figures		2000-03-10
		From Erica: Yesterday, I recieved a test problem asking to prove two line segments equal. Here is the problem as I was given it: Given: paralleogram ABCD AE is perpendicular to DB CF is perpendicular to DB Prove: AE is equal to CF I answered the problem as follows: . . . Answered by Walter Whiteley.
	A goat problem		2000-03-10
		From Nancy: A farmer has a fenced-in, circular field with an area of about one acre. A goat in the field is tethered to one of the fence posts with a rope which gives the goat approximately one-half acre of grazing area. To the nearest foot, how long is the rope? Answered by Chris Fisher.
	Systems of linear equations		2000-03-10
		From Ann Marie Devereux: hi there!!, I guess I have a problem!!! 3x+4y=10 (over) 4x+y=9 2x=5y+3 (over) x=3y+1 Answered by Penny Nom.
	Grazing area for a goat		2000-03-10
		From Amy: A goat is tied in the middle of a side of a square building whose sides are 2 yards long. The rope is 4 yards long. What is the grazing area for the goat? Answered by Harley Weston.
	Box and whisker plots		2000-03-09
		From Brett Blake: Do you have any information on Box and whisker graphs? Answered by Harley Weston.
	Some equations		2000-03-08
		From Maria: Hi, could you help me with these questions: Find x & solve 7-2x/3=9 4x+3/5=-2 6-2x=14 -1/7x=-4/3+1/6 Answered by Penny Nom.
	Mathematical deduction and mathematical induction		2000-03-07
		From Espera Pax: What are mathematical deduction and mathematical induction, and what is the difference between them? Answered by Harley Weston.
	Making dolls		2000-03-07
		From A 6th grader: How many small dolls can be made from 3 lbs. of dough if each doll uses 7/8 lbs same question if each doll takes 3/8 lbs. Answered by Penny Nom.
	A mixture problem		2000-03-06
		From Rebecca Edwards: A tank in which cholocate milk is being mixed contains a mixture of 460 liters of milk and 40 liters of chocolate syrup initially. Syrup and milk are then added to the tank at the rate of 2 liters per minute of syrup and 8 liters of milk per minute. Simultaneously the mixture is withdrawn at the rate of 10 liters per minute. Find the function giving the amount of syrup in the tank at time t. Answered by Harley Weston.
	Is a sheet of paper 2-dimensional?		2000-03-06
		From Jaclyn Evans: One day, we were discussing 3-dimensional items. Is a sheet of paper considered a 3-dimensional shape? Or is it 2-dimensional as described by 8.5 by 11 size? Also, could you give me an example of a 4-dimensional item or scenario? Answered by Harley Weston.
	10 000 000 = a x b		2000-03-06
		From Spencer Jaffe: What two numbers that don't end in zero, multiplied equal 10,000,000. Answered by Claude tardif.
	Two calculus problems		2000-03-03
		From Tara Doucet: The height of a cylinder with a radius of 4 cm is increasing at rate of 2 cm per minute. Find the rate of change of the volume of the cylinder with respect to time when the height is 10 cm. A 24 cm piece of string is cut in two pieces. One piece is used to form a circle and the other to form a square. How should the string be cut so the sum of the areas is a maximum? Answered by Harley Weston.
	Angle of Intersection of Two Lines		2000-03-02
		From Veronica Patterson: I am having a real hard time trying to figure out this problem. Could you please help me! The homework question says to find the acute angle of intersection between the two lines y=3x+1 and y=(1/2)x-1. (It also says to use the results of a problem I had already figured out.) That problem was to use information from a picture shown that tan(theta sub1-theta sub2)= ((m sub2- m sub1)/(1+(m sub1 * m sub2))). I used the difference identity of tangent to figure out the answer. Any help on this problem would be greatly appreciated. Answered by Harley Weston.
	Triangular numbers and square numbers		2000-03-02
		From Emily McCallum: Would someone find me some math activities using triangular numbers and square number. Especially acitivities that actually form the shapes. They need to be at the 5th grade or 6th grade level. But you can not find anything that can be tauht at these level, that fine. I just need to be able to teach this new subject or kind of math to my kids. Answered by Rick Seaman and Penny Nom.
	The positive effects of mathematics on human's thought		2000-03-02
		From Yucel Tucker: I am a student of secondary school. I have to prepare a homework about " the positive effects of mathematics on human's thought". If you help me I'll be pleased. thank you... Answered by Walter Whiteley.
	Pythagorean triples		2000-03-01
		From Bob Ross: Could you please tell me what pythagoria triad is.I am a year 10 student. Answered by Chris Fisher.
	Proportionality in a triangle		2000-03-01
		From Courtney Smith: I would appreciate assistance with the following problem In triangle ABC,segment MN divides sides(segment)AC and (segment)AB proportionally. If the coordinates are A(3,7),M(0,10) and N(8,22) and if AM:MC = 3:1, find the coordinates of B and C. Answered by Penny Nom.
	Saving for college		2000-03-01
		From Andrew Kunz: SAVING FOR COLLEGE In this project, you will forecast a friend's finances. Jane has received $75 from her grandparents on every birthday since she was one year old. She has been saving the money in an account that pays 5% interest. She is saving her money to help you pay for her college education, which she will start this fall after her 18th birthday. She also has been receiving birthday checks from her other relatives, but these didn't start until she was 12 years old. The amounts of these checks from her 12th birthday until her 18th birthday are $45, $45, $55, $50, $55, $60, $65. How much money will she have saved just from her birthdays by the time she starts college? IS this a reasonable amount to pay for a used car during her junior year in college? If she had invested her money in a different accoutn that had earned 7% interest, how much more money would she have saved? Answered by Penny Nom.
	Folding a page		2000-03-01
		From Krista Bischoff: One corner of a page of width a is folded over and just reaches the opposite side. Express L, the length of the crease, in terms of x and a. I can't get the picture to copy to this form so I guess I will have to try and describe the picture the best that I can. The top right hand corner is folded to the left side, almost half way down. The width of the paper is a ( the width of the bottom part which is not folded.) The creased side is L and the part shorter part of the folded area is x (the part that would have been the top right of the original piece.) Answered by Chris Fisher.
	What's the next term?		2000-02-29
		From Meredith O'Neill: At this point, the whole family wants to know the answer. if possible an explanation. thanks a sequence ? 16,37,58,89,145 ?? Answered by Chris Fisher.
	Area of a circle		2000-02-29
		From Michelle Buboltz: My name is michelle and I just need to convert 25 ft across a circle into how many square feet. Answered by Penny Nom.
	A negative times a negative		2000-02-29
		From Michael J. Butler: I have reviewed the answer in relation to the question of why (-3)x(-2)=6; however, I am still not able to properly explain the reasoning to my son, Jonathan, who is in grade 7. I want him to understand the reason for the rule that the multiplication or division of two negative numbers equals a positive number. Can you help? Answered by Chris Fisher.
	Order of operations		2000-02-27
		From Mildred Saulsbery: Find the value of the expression. 6(5+1) - 9(1+1) _____________ 5(8 - 6) -23 Answered by Harley Weston.
	Fractions in algebra		2000-02-27
		From Leslie: Question: add (4x+1)/(x-8) + (3x+2)/(x+4) + (49x+4)/(x^2-4x-32) and solve x - 6/(x-3) = 2x(x-3) Answered by Penny Nom.
	Factoring, primes, GCF and LCM		2000-02-27
		From Ruth Kroek: My son is in grade seven, he has to do a Factoring Booklet the areas covered are: Prime #'s Composite #'s Rainbow Factoring Finding Multiples (consecutive multiples) Finding GCF of 2-3 numbers uning Rainbow factoring Finding LCM of 2 numbers using consecutive multiples prime factor trees prime factor ladders finding GCF of 2 numbers using Prime number Method Although his text 'Math Power' gives some information, we are at a loss .. Answered by Penny Nom.
	Building a pyramid		2000-02-26
		From Francis X. Hines Jr.: I am presently trying to build a pyramid. I can understand that the base has 90 degree angles on the first plane which is the outline of the square that makes up the floor. As close as I can figure the slope of each wall face is 35 degrees or 35.7 to be exact if I am correct by using 360 as the total of the three interior angles.Now , I run into a compound angle where the corners meet what would be the angle created by the two 35 degree angles that would allow for the 90 degree edge to continue. Because I'm working in three dimensions I also need to be sure that my math would be correct when I substract 35 from 90 to aquire the angle of the narrow edge as to allow for a 90 degree surface to be present ..to allow for another level to be added with only the base line being shortened. I hope you can understand what it is that I'm asking assistance with.I would greatly appericate your help. Answered by Chris Fisher.
	Polar coordinates		2000-02-24
		From Tran Trung: How do I convert r = 2/(2sin(theta) - 3cos(theta)) to rectangular and x2 + y2 -2y = 0 to polar form? Answered by Harley Weston.
	Slant height of a cone		2000-02-24
		From Jocelyn Wozney: I need help with this problem for my high school calculus class. Any help you can give me will be greatly appreciated-I am pretty stumped. "Express the volume of a cone in terms of the slant height 'e' and the semi-vertical angle 'x' and find the value of 'x' for which the volume is a maximum if 'e' is constant. Answered by Harley Weston.
	The isoperimetric theorem		2000-02-24
		From Raj Bobal: How can you prove Mathematically that the maximum area enclosed by a given length is a circle? Answered by Chris Fisher.
	Hexagons		2000-02-23
		From Mohd. Amjad: I want to know about hexagons. What is the area and the perimeter of an hexagon? Answered by Penny Nom.
	More on googols		2000-02-23
		From Kevin Brennan: Could you please give me a couple of examples of when you MATH guys would use a google. Do youu measure, like, galaxies with it ? Or was it created to keep track of Mr Gate's bank account. Answered by Penny Nom.
	Triple angle formula		2000-02-23
		From Sara: Can one derive a triple angle formula for sine and cosine? If so, how? Answered by Chris Fisher.
	A triangle and a circle		2000-02-23
		From wendy: If a triangle of base 6 has the same area as a circle of radius 6, what is the altitude of the triangle? I am having trouble with altitude. Answered by Penny Nom.
	Some integration problems		2000-02-23
		From Tim Valentine: I am having a great deal of difficulty with the following integrals, can you help? I think they need the use of trig substitution or integration by parts but I cannot figure out how to begin. Thanks! The integral of 1/(2+3x2) dx. and The integral of x * square root of (4x+5) dx. Answered by Harley Weston.
	A trig identiry		2000-02-23
		From Ashlee: I am having problems doing this problem. Can you help? Verify the identity: (1+cot2X)(1-cos2X)=2 Answered by Harley Weston.
	Party favors		2000-02-22
		From Krystina Fernandez: Luanne was making party favors for her little sister's birthday party. Each party favor was in the shape of a cube. Luanne had pink and purple paint to paint the cubes and she could paint each face only solid pink or solid purple (no dots,stripes,ect.).For example, one cube may be all purple, another may have two purple faces and four pink faces. Her little sister wanted to have a different cube for each guest.(A cube is not considered different if it can be turned so that all it's sides match the corresponding sides of another cube.)How many different cubes was it possible for Luanne to make? Answered by Claude Tardif.
	A moving point on the graph of y=sinx		2000-02-22
		From Veronica Patterson: Find the rate of change of the distance between the origin and a moving point on the graph of y=sinx if dx/dt=2 centimeters per second. Answered by Harley Weston.
	Pi		2000-02-22
		From Shelley Collier: Numbers that can be written in the form p/q where p and q are integers, (q not 0), are known as rational numbers. What you are missing is that p and q must be integers. The fact that Pi is irrational means that you can't have a circle with both the circumference and diameter being integers. In fact you can't even have the circumference and diameter both rational since the quotient of two rationals is again a rational. Answered by Claude Tardif and Penny Nom.
	A valentines project		2000-02-21
		From Courtney Dohoney: I was assigned a valentines project. Our job is to make a valentines card that has a math theme. On my valentines card I would like to include the set of equations that when graphed look like a heart. If you can figure out a set of equations and get it back to me I would be very happy. Answered by Harley Weston.
	The quotient rule		2000-02-21
		From Charlene Anderson: Question: I came across a question in our book that states: Let Q(x) = N(x) / D(x) Then re-write Q(x) in a form that can utilize the Power and Product Rules. Use this rearranged form to derive the Quotient Rule. The Quotient Rule can be derived from the Power Rule and the Product Rule. One must also use the chain rule too, right? Answered by Harley Weston.
	Mass of the earth		2000-02-21
		From Terry Broughton: My name is terry i am 15 my question is how much does our planet earth weigh ? Answered by Chris Fisher and Harley Weston.
	Why counterclockwise?		2000-02-21
		From Drew: Why do the numbers of quadrants in a graph increase in a counter clockwise pattern? Why aren't they numbered increasingly in a clockwise pattern? Answered by Chris Fisher.
	Irrational algebraic functions		2000-02-21
		From Bucky Cadena: Here is the multipart problem: Given f(x) = x-3* squareroot of x + 4 What does the f(x) intercept equal Find the two values for which f(x) = -5 Find the one value for which f(x) = -3 Answered by Harley Weston.
	Three factors		2000-02-21
		From A parent: Question from a parent helping a child, grade 4, with homework. Can a number have three factors? Name three numbers that have three factors. Answered by Penny Nom.
	Perimeter of an ellipse		2000-02-21
		From Kurtis Proffit: What is the formula for the perimeter or circumference of an ellipse? Answered by Chris Fisher.
	Number sense		2000-02-17
		From A college student: I am a college student and I am to answer the following question: Describe ways of telling by simple inspection when a fraction has a value close to 0; close to 1/2; and close to 1. I am to imagine that I am a 3rd grader answering this question. Any thoughts please? Answered by Penny Nom.
	Jogging up a hill		2000-02-17
		From Aaron Williams: A man jogs down the hill at 6 miles per hour and back up at 4 miles per hour. The total time that he travels is 5/4 hours. What is the total distance that he jogged. The solution is supposedely 3 miles, but i believe that it is 6. Can you help me? Please. Answered by Claude Tardif.
	A trig identity		2000-02-17
		From Eric: Question: How do I solve this problem? sin3x cos3x _____ - _____ = 2 sinx cosx Answered by Chris Fisher.
	The length of a cylinder		2000-02-17
		From Kelly Wichmann: What is the formula to figure the volume of a cylinder? We have a cylinder that is 2 3/4" in inside diameter and a gallon of oil that needs to fill it. We are trying to figure out how long the cylinder should be. Can you help us? Answered by Chris Fisher.
	Cross multiplication		2000-02-16
		From J E Swinton: Why does cross multiplication work? How come canceling work? Answered by Penny Nom.
	Least Common Multiple		2000-02-16
		From Kathy Heath: The way I understand it is for 2,3,9 the least common multiple is 18. Am I right? If so, I guess the least common multiple for 3,4,7 is 105. Please let me know if I'm right so I can tell my daughter. Answered by Denis Hanson.
	Change for a dollar		2000-02-16
		From Rachelle: What is the least positive number of coins that is impossible to give out change for a dollar? It is higher than 50 i know and you can us dimes, nickels, pennies, quarters, 50 cent pieaces and silver dollars. Answered by Claude Tardif.
	2 = 1		2000-02-16
		From Chuck Kennedy: Question: Assume a=b Multiply both sides by a, a2=ab Subtract b2, a2-b2=ab-b2 Factor (a-b)(a+b)=b(a-b) Cancel like factors a+b=b Substitue b for a b+b=b Then 2b=b Therefore 2=1 Question; Were is the mistake? Answered by Claude Tardif.
	Midpoints and endpoints		2000-02-15
		From Jessica Sipes: I need to know how to find and endpoint using the midpoint and the other endpoint. Answered by Penny Nom.
	Weighing bales		2000-02-15
		From Thinh Than: You have 5 bales of hay. and they were weighed but they didn't weigh them individually, they were weighed in pairs. The pairs were 1&2, 1&3, 1&4, 1&5, 2&3, 2&4, 2&5, and so on. The weights of the pairs were 80,82,83,84,85,86,87,88,90, and 91. Can you tell me how much the bales weigh individually. Answered by Claude Tardif.
	Factors		2000-02-15
		From Guy Rayfield: Please can you tell me the factors of 6 I think the answer is 2 and 3 - am I right? Answered by Penny Nom.
	Is a square a rectangle?		2000-02-15
		From Jaireh: This is something that aroused a debate in class: A rectangle was defined as a parallelogram with 4 right angles. A square was defined as a parallelogram with 4 congruent sides and 4 right angles. I need written and conclusive proof that some rectangles can or cannot be squares. I tried insisting that some of them can.. but without proof nobody will listen. Answered by Walter Whiteley.
	The sum of repeating decimals		2000-02-15
		From Caitlin Harris: Express 0.111... + 0.121212... + 0.123123123... as a repeating decimal and its equivalent fraction. Show work. Also, are there any extensions to this problem? In other words, are there any questions that we could ask that may be related to this problem? Answered by Penny Nom.
	Counting to a trillion		2000-02-06
		From Art Keck: If I counted one dollar every second, would it take 31,000 years to count to a trillion? If not, could you please explain how long it yould take? Answered by Penny Nom.
	Ten stools		2000-02-06
		From Haim: In a cafe with ten stools, three customers want to be seated, so that no two are next to each other. How many ways can this be done? Do not consider it to be a separate seating if two customers switch seats. Answered by Denis Hanson and Walter Whiteley.
	A 4-by-4 magic square		2000-02-06
		From Maureen Fitzsimons: I need to create a 4x4 grid using numbers .1, .2, .3, .4, ....1.1, 1.2, 1.3,1.4,1.5,1.6 the sum of the number diagonally, horizontally and across all equal 3.4 Answered by Penny Nom.
	Is zero an even or odd number?		2000-02-06
		From Christian Hansen: On a list I run, someone posted that 02-02-2000 was the first date since 28-08-888 where all the digits were even. Of course, this provoked a discussion of whether zero was odd, or even, or neither. I remember reading that, for symmetry's sake, it is considered by mathematicians to be even. Any thoughts? Answered by Patrick Maidorn.
	Percentages with decimals		2000-02-06
		From Andrew Connell: I need help with these math questions: How does one convert a percent to a fraction when the percent has a decimal (example-86.5%)? Answered by Penny Nom.
	Tennis doubles		2000-02-04
		From Brittany Allinson: Cheri, Beth and Jacinta are daughters of Mr. Sullivan, Mr. Marchand, and Mr. Benoit. Four of these people are playing tennis doubles. Mr. Benoit's daughter and Mr. Sullivan are partners. Cheri's father and Mr. Marchand's daughter are also partners. There aren't any father/daughter combinations. Who is Cheri's father? Answered by Penny Nom.
	Filbert Family Circus		2000-02-04
		From Sarah: As Clyde moves his broom around the circus ring, he thinks that he has finally found a job where he can make a clean sweep of things. Clyde is sweeping the ring where the lions perform in the Filbert Family Circus. The ring is 76 feet across and Clyde is using a broom 3 feet wide. He starts at the outside edge and works his way to the middle, making circles around the ring. After sweeping 3/4 of the ring, Clyde sees the lions coming with their trainer and scurries out of the ring. How many trips around the ring did he make? Answered by Penny Nom.
	A 16th century mathematician		2000-02-04
		From Danielle Dombrowski: My name is Danielle Dombrowski, I am in the 7th grade and my teacher gave us a riddle to figure out which mathemtician we would have to do a report on. The only problem is that I don't know what the answer is. Can you help? The riddle is "This 16th century mathematician, having predicted the day of his death, took poison to make sure it came true. Who is it?" Answered by Penny Nom.
	Play ball		2000-02-03
		From Jessie: Here's a calc question that is probably a lot easier than I am making it. If you have a legendary "baseball problem" for the related rates section of Calc I, and you are given that the runner is running from 2nd to 3rd base at a given rate, and the umpire is standing at home plate, and you are given the distance between the bases on the field, how do you find the rate of change of the angle between the third base line (from the point of the umpire) and the runner? Here is a sample prob: Runner is moving from 2nd to 3rd base at a rate of 24 feet per second. Distance between the bases is 90 feet. What is the rate of change for the angle (theta, as described previously) when the runner is 30 feet from 3rd base? Answered by Harley Weston.
	A problem with a radius.		2000-02-01
		From Howard B Davis: We start a Line that goes up 1 unit, then it goes to the Right for 5 units long, and then goes down 1 unit which is the end point. If we draw a circle that is tangent to both ends as well as the mid-point of the horizontal line: How do we find the radius of the arc; in Mathematics, with only this information? Answered by Chris Fisher.
	100% on two tests		2000-02-01
		From Craig and Chelsea Bruzzone: A class of 35 students took a math test and a science test. 12 students got 100% on the math test. 9 students got 100% on the science test. There were 19 students who made less than 100% on both tests. How many students made 100% on both tests? Answered by Penny Nom.
	Mark's life		2000-01-30
		From Jean and Larry Brandemuehl: Mark passed 1/6 of his life in childhood, 1/12 in youth, and 1/7 more as a bachelor. Five years after his marriage, there was born a son who died four years before his father, at half his father's (final) age. How old was Mark when he died? Answered by Penny Nom.
	Percent of improvement		2000-01-30
		From Steve Quigg: In a 1998 survey, 21% polled responded favorably to a question. In 1999, 31% responded favorably. What is the percent of improvement? Answered by Harley Weston.
	Can't make an equation!		2000-01-30
		From Maggie Clarke: An estate is to be distributed among the wife, 3 children and 2 grandchildren. The children will each receive 2x as much as each grandchild, and the wife will receive 4x as much as each child. If the estate amounted to $115,000, how much will each person receive? Answered by Penny Nom.
	Names of the polygons		2000-01-29
		From Janemath: I have been doing research on the names of polygons with 11 to 20 sides. I have found conflicting names for some of them . for example 18 sided-octadecagon and octokaidecagon. 11sided-undecagon and hendecagon. Why is this? Is one more correct than another? Or are they equally acceptable? Answered by Harley Weston.
	Two problems		2000-01-29
		From D. J. Anthony: Hi, I am taking a course "math for elementary teachers" and I have two problems. How thick is a sheet of paper in your textbook. A little island has a population of 1,000 people. It doubles every 30 years. What will the population be in 30 years?, in 60 years?, when will it be over one million? Answered by Peny Nom and Claude Tardif.
	Compatible numbers		2000-01-27
		From Angie: Use compatible numbers to estimate each product and quotient. 23*1/2 1/3*11 Answered by Penny Nom.
	Factors		2000-01-27
		From Pam: My son [age 9, 4th grade] has a math problem with factors. I need to know how to do the problem that involves the factor 24. I'm not even sure where to start. Answered by Harley Weston.
	Probability, graph theory and VLSI testing		2000-01-27
		From Valentin Muresan: I am postgraduate student of Dublin City University, Ireland, in the field of VLSI Testing. I am currently working on some heuristics and I need a probability formula. I want to get an expert's point of view in my matter. Say there is an initial list of so called tests: T1, T2, T3, ..., Tn Every test element Ti of the above list has a list of compatibility (incompatibility), which includes all the elements (tests) from the initial list, the Ti test is compatible (incompatible) with. For example, say the initial list is: {T1, T2, T3, T4, T5, T6, T7, T8, T9, T10} and the compatibility lists of these elements (tests) are: . . . Answered by Denis Hanson.
	Quadratics		2000-01-27
		From Lori: Hi my name is Lori. I'm a student, in the 11th grade.I have a problem in quadratic functions. I don't know how to get the numbers into the problem and then how to do the problem. here is one problem the rest are sort of similar to it... y=2x squared. If I were to find out how to get the (x,y) answers then I could graph it but as I said I can't find the numbers to go into the problem. Also in the equation g: x arrow to y = -x + 4..... how would you know weather it is or isn't a quadratic equation???? Answered by Penny Nom.
	Counting guppies		2000-01-26
		From Sarah Albaugh: Out of 200 fish, 99% are guppies. How many guppies must be removed to have 98% of the remaining fish to be guppies? Answered by Penny Nom.
	Quadratic		2000-01-26
		From Karen Johnson: What is the reasoning behind the title quadratic equation? Answered by Penny Nom.
	Mixing oil and gas		2000-01-25
		From Karen: My hubby is ready to use his snow blower and is supposed to use 50:1 measurement....50 parts gas to 1 part oil......how does he do this if he has 1 gallon of gas? How much oil do we use...need info asap.....hopefully you are there! Answered by Harley Weston.
	Complex Roots		2000-01-24
		From Jess Rutherford: How do I find the value of k when 5x2 + k = 3x and has complex roots ? Answered by Penny Nom.
	Euclidean Math puzzle		2000-01-24
		From Margaret Matthews: (Check out this web-site: Simeon's Triangle Puzzle ) I have tried to figure out how this could be, because everything I know about it tells me it can't be. However, I can't seem to make it NOT work. Two right angle triangles. They are each cut up into four identical pieces. In the first, all the pieces fit together so that there are NO empty spaces; in the second, presumed to be identical in size to the first, the pieces are slightly rearranged, and now, there IS a space in the triangle. Answered by Patrick Maidorn and Claude Tardif.
	Word problem		2000-01-24
		From April: Ok, my algerbra teacher gave me this problem and by just looking at it I can tell what the answer is but he wants me to show how I got the answer in an equation form. The tempature at 7am on a cold day was -4 degrees Celcius. At 3pm the tempature was 1 degree Celcius. Write and solve an equation to find out how many degrees the tempature rose between 7am and and 3pm. Answered by Penny Nom.
	Functions		2000-01-23
		From Tara: Hi my name is Tara, I have two math problems that I need help with in my calculus math class. If f(x)= x - 2 show that (x+3)f(x)-(x+2)f(x+1)+4=0 Graph this function and use the graph to determine the range y=2x2 - 8x - 3 Answered by Harley Weston.
	Frogs and lily pads		2000-01-23
		From Nick: There are 5 lily pads and 4 frogs, 2 Red and 2 Green, how many moves does it take for them to swap sides? Answer: 8 I have a formula which will tell you how many moves it will take with different total numbers of frogs, it is [(F*F)/4]+F Where F is the number of red frogs add the number of Green frogs. This formula only works with numbers of frogs that are the same on each side. What I would like to know is why this formula works and why you have to divide it by 4? Answered by Penny Nom.
	The limit of f(x)/x		2000-01-22
		From Laurent Jullien: I would appreciate help to prove that a twice continuously differentiable convex function from R+ to R has the property that f(x)/x has a limit when x tends to infinity. Answered by Claude Tardif.
	Domain of a function		2000-01-19
		From Stacey Hutchison: What is the domain of: f(x) = -1/(x + 4) Answered by Patrick Maidorn.
	Arclength of a circle		2000-01-19
		From Holly: What is the formoula for finding the arc length of a central angle of a circle?? Answered by Harley Weston.
	Logarithms		2000-01-18
		From Jennifer: Hi I have a test tomorrow and I was wondering if you could help me with these two problems. Explain how to express y in terms of x if log3y=4log3(2X) The LN key on your scientific calculator is not working, but the ex and LOG keys are. Write directions for calculating a natural logarithm using the ex and LOG keys. Explain why these directions will get you the right answer. Answered by Harley Weston.
	Pyramids and prisms		2000-01-18
		From Tyler: What's the definition of a Triangular Prism and a Triangular pyramid. Answered by Penny Nom.
	Algebra		2000-01-18
		From Candis: I want to know what exactly is Algebra? Not how to do it, or methods. Just what is it? Answered by Allen Herman.
	Ax + By = C		2000-01-18
		From Fatiha Khanboubi: I was wondering if you could please explain to me how I would write the equation of line through the given points [(4,1), (6,3)] in Ax+By=C form. Answered by Harley Weston.
	Solving an equation		2000-01-17
		From Shelley's Mom: My daughter has an assignment in math that includes this equation: -6b+5= -10 I've tried to help her with a scale. We've figured that you subtract 5 from each equation so its not -6b = -15. Is this correct and can you help us figure out the next step? Answered by Penny Nom.
	An unbelievable story		2000-01-17
		From Melissa: good morning-i am taking a course "math for elementary teachers" and i have a take home problem that i really need help on. here is the question -the million dollar problem a recent item in the newspaper described a robbery in which the robber had held up a local bank for 1 million dollars in small bills, had the tellers put the money in a briefcase which he gave them, and fled the scene on foot. is this story believable? explain your answer! Answered by Harley Weston.
	Taxicab geometry		2000-01-16
		From Jack: Im doing an investigation entitled 'taxicab geometry', ive attempted it and have done most of the practical part of it. But i cant seem to see the equation behind it all. please guide me in the right direction. They provide a regular grid with regular horizontal and vertical lines. The lines are roads and the actual squares are blocks of hoouses/ buildings. In taxicab geometry the distance between place A & B is worked out by adding together the horizontal and vertical distances. each square is counted as i unit. Part 1 (I've done this) A taxix cab firm is based at A. the posistion B is 7 units away from A. investigate all the posistions of B at 7 units. investigate for different distances. . . . Answered by Penny Nom.
	Order of operations		2000-01-16
		From Dorothy: I was wondering if you could tell me where I can get some info. on how to solve the following problem. I was given the answer but I don't know how it is solved. 4+2x(6x2)-5=23 Answered by Penny Nom.
	A roll of paper		2000-01-15
		From Richard: I have a roll of paper, wrapped around a corrugate core, whos diameter is 10.750 in. The outer diameter of the roll is approx. 60 in. The thickness of the paper is .014 in. I am trying to find out how much linear feet of paper is left on the roll, given only the diameter of paper remaining on the core. Answered by Chris Fisher and Harley Weston.
	A three digit number		2000-01-13
		From Manali Shah: My son is in 5th grade, he has a math problem. There is three digit number, which is greater than 500, can be divided by 7,9 and 11, but cannot be divided by 2,4,6, and 5. Answered by Harley Weston.
	Algebra		2000-01-13
		From Tim Merrill: "please help me out with these four algebra questions" Rewrite the following using positive exponents only. xy -3 ------- x -2 Find the following quotients. 9a3+3a2+6a -------------- 3a . . . Answered by Penny Nom.
	Parallel lines		2000-01-12
		From Lori: Find an equation of the line parallel to the given line containing the given point. x + y = 2; (1,2) We know parallel line have the same slope and we know the answer y = -x + 3. Answered by Penny Nom.
	Addition		2000-01-11
		From Deanna: what is the answer for 20+5+32-3+98 Answered by Penny Nom.
	Three dimensional rectangle		2000-01-11
		From Dennis Murphy: I would like to find out the name of a Three dimensional rectangle. Answered by Harley Weston.
	Bar graphs and histograms		2000-01-11
		From Raeluck: What is the difference between a bar graph and a histogram? Answered by Harley Weston.
	Factoring by graphing		2000-01-11
		From Dylan Kirkwood: How can you factor a quadratic equation by graphing it? Answered by Penny Nom.
	Ratios		2000-01-11
		From Cyndi: My name is Cyndi and i am in middle school in the 8th grade. The questions i am about to ask come from my book. My return address is PR_Angel1@yahoo.com The directions on a can of lemonade mix say to use 8 tablespoons of mix to make 2 quarts of lemonade. Heathcliff wants to make 7 quarts of lemonade. How many tablespoons of mix should he use? and In a recent year, the ratio of men to women in the United States armed forces were about 9 to 1 if there are 90 men in a random group of military personnel, how many women would you expect to find in the group? in a group of 90 military personnel, how many of them would you expect to be women? what percent of armed forces personnel were women in that year? Answered by Penny Nom.
	Parallel planes		2000-01-10
		From Hugo Alvarez: When two parallel planes are cut by a third plane, the lines of the intersection are? Answered by Claude Tardif.
	Phone Number Possibilities		2000-01-09
		From Hamilton Weston: How do phone companies arrive at the possible number of phone numbers that can be generated for customers? Answered by Harley Weston.
	Capacitor discharge rate		2000-01-09
		From Bill Phillips: I need to be solve for t in the following rate problem for an electrical capacitor. Vr = E(e^-t/RC), e=nat. log 2.718 raised to the -t/RC power. Answered by Harley Weston.
	Percentages		2000-01-09
		From Nancy: What is the best way for a parent to explain how one calculates percentages? ie. Commission is $54268. Total Sales $403114.00 from that number how do you calculate the percentage of sales of various expenses. Answered by Penny Nom.
	How many coins is one calculator?		2000-01-09
		From Mandy Brockmann: Tom weighed 1 pen and his calculator with 4 coins. Then he weighed his calculator and 3 pens with 12 coins. How many coins is one calculator? Answered by Claude Tardif.
	Functions		2000-01-06
		From Tori Morris: Consider the function f(x)=x2-3. Which of the following are true? f(1)>f(0) f(2)>f(-3) f(2)=f(-2) f(-1)=f(3). More than one answer can be true. Answered by Penny Nom.
	Angles		2000-01-06
		From Rayna: I am doing a presentation report on angles which has to be fun and entertaining as well as educational. I am having problems locating resources on angles that give me ideas of fun entertaining projects. My lecture is to be about 20 minutes long infront of a class of 11th and 12th graders. Please Help if you can. Answered by Claude Tardif and Walter Whiteley.
	Ordering fractions		2000-01-05
		From A seventh grader: I am a middle school student (7th grade) and I was wondering if you could help me with ordering fractions from least to greatest the fractions are 31/12, 2 5/6 and 2 3/4. Answered by Walter Whiteley.
	A probability experiment		2000-01-05
		From Vanessa: Duels in the town of Discretion are rarely fatal. There, each contestant comes at a random moment between 5 a.m. and 6 a.m. on the appointed day and leaves exactly 5 minutes later, honor served, unless his opponent arrives within the time interval and then they fight. What fraction of duels lead to violence? There must be a minimum number of 100 trials and things like graphing calculator, dice, spinners, and whatever are allowed. Answered by Harley Weston.
	Why study calculus?		2000-01-05
		From Trlpal: I am a high school senior enrolled in a pre-calculus class. Could you tell me what the benefits of taking calculus are and why it would be important to take the class. Answered by Walter Whiteley and Harley Weston.
	Factoring ^6		2000-01-03
		From Athena: my name is Athena and I have a question on factoring: how would you figure this out: (x6-y6) and (x6+y6) Answered by Penny Nom.
	Y-intercept		2000-01-03
		From Kayla Boylan: How do you use and find the y-intercept? Answered by Penny Nom.
	zero		2000-01-01
		From Jason: What civilization first used zero? Answered by Penny Nom.
	Derive the quadratic equation		2000-01-01
		From Thuy: My teacher asked us this question in which i can't understand when she asked to derive the quadratic equation. What does this mean? Answered by Penny Nom.
	Solving a cubic equation		1999-12-30
		From Natalia: How can I solve: 2 x3 - x2 + x - 2 = 0 ??? Answered by Penny Nom.
	Absolute value		1999-12-29
		From Alex Waller: What are some practical applications for absolute value? Answered by Harley Weston.
	Period		1999-12-28
		From Mahdawi: I have attached a diagram of the graph, and I need to find out its period. I really don't understand how to do so, please help! Answered by Harley Weston.
	Parachute Problem		1999-12-28
		From Stephanie Zinsli: A parachutist jumps from an airplane and lands in a square field that is 2 kilometers on each side. In each corner of the field there is a large tree. The parachutist's ropes will get tangled in the tree if she lands within 1/11 kilometer of its trunk. What is the probability that she will land in the field without getting caught in a tree? Answered by Penny Nom.
	Three algebra problems		1999-12-28
		From Stephanie Branton: If P represents the product of all prime numbers less than 1000, what is the value of the unit's digit of P? Do any real numbers a and b exist such that: ln(a+b)=ln a + ln b? if so, what are they? Define a function by: f(x)=1/1-x where x is not equal to 0,1. what is f(f(f(a)))? Answered by Harley Weston.
	Graph of a sine function		1999-12-23
		From Pierre: Given; amplitute:1 period: 540 Phase shift: 60 degree,right I am ask to right the equation: sin 2/3 (value -60degree) When I am asked to graph the equation, the period is mixing me up. Answered by Harley Weston.
	Climbing stairs		1999-12-22
		From Harman Chaudhry: Paul, Michelle and Michael all climb up 54 steps. Paul climbs the steps one at a time i.e. 1, 2, 3, etc. Michelle Climbs the stairs 2 at a time i.e. 2, 4, 6, etc. Michael climbs the stairs 3 at a time i.e. 3, 6, 9, etc. How many steps are used by exactly two people? Answered by Penny Nom.
	Specific heat		1999-12-22
		From Irena: In transferring 1260J of heat to water, the temperature of 0.20 kg of mercury falls 50 K. Calculate the specific heat capacity of mercury using the equation C= Q/(m)(delta t) i know that Q= -1260J because it's loosing heat and m= 0.2kg and since i have to use 'C i have to convert Kelvins into Celsius (i also know that 'C has to be negative since it looses heat) . . . Answered by Harley Weston.
	Approximations		1999-12-20
		From Adrian Valc: Long-time ago I red an article about surprizing (and in a way frustrating) results in math, for example the limit of a nicely defined infinite series which was believed to be a simple rational number, but later was determined to be a transcendent number that missed the rational value by an incredibly small amount (so for example the limit proved to be 2.75000...00137.. with a lot of 0's in between). I cannot find that article anymore, so i was wondering if you have any such examples, or you can point to any relevant information source? Answered by Chris Fisher.
	Comma as decimal separator		1999-12-18
		From Franck Menuge: Could somebody tell me the origin of the use of a 'comma' as a decimal separator and of a 'dot' for thousands in the French numeric system, ex.1.234,56 Is it only used in France or in other european coutries? Why is it different in the UK? Answered by Patrick Maidorn and Penny Nom.
	The area of a garden		1999-12-17
		From Jessica Wells: Hi My name is Jessica Wells and I am 10 years old. I was hoping you could help me out wityh a question my dad gave me. It is if aq graden is 32cm in diameter and I want to know the area of it what process do I use? He's a math wiz so I need o show him that I'm smart too Answered by Penny Nom.
	Two algebra problems		1999-12-17
		From Michael Standfest: If x+4 is a factor of 2x4+kx3-3kx2+6x-40, find k and Prove that n2-n is even for all n, using the proof of contradiction Answered by Penny Nom.
	Proving a trigonometric identitiy		1999-12-17
		From Ryan: I need to figure out how to prove that sec2x + csc2x = sec2x csc2x. I am not sure where to start out with it and whether I should use reciprocal, quotient, or pythagorean. Answered by Penny Nom.
	Logarithms		1999-12-16
		From Pierre: Can you please answer those three question inverse or the exponential function. logx 81 = 4, x expo4 = 81, x = +or- 4square root 81, x = +or- 3 s.s = {3} Why is -3 not acceptable. . . . Answered by Harley Weston.
	Rectangular hyperbola		1999-12-15
		From Aarti Chand: Why do they call a rectangular hyperbola, rectangular and where the normal hyperbola looks like a rectangle and the rectangular hyperbola looks like a sqaure? Answered by Chris Fisher.
	A decreasing ellipsoid		1999-12-15
		From A student instructor: The volume of an ellipsoid whose semiaxes are of the lengths a,b,and c is 4/3 *pi*abc. Suppose semiaxes a is changing at a rate of A cm/s , the semiaxes b is changing at B cm/s and the semiaxes c is changing at C cm/s . If the volume of the ellipsoid is decreasing when a=b=c what can you say about A,B,C? Justify. Answered by Harley Weston.
	A model area		1999-12-15
		From John Ost: Hello, I am a college student taking an elementary math course I need if possible assistance to developing an area model 36 x 25 that shows each of the four separate partial products. I must know how to do the computation 36x25 showing each of the four partial products separately, and indicate how each corresponds to the drawing that is required of the area model. Answered by Penny Nom.
	Cutting a carpet		1999-12-15
		From Heather: A rectanglular piece of carpeting is 90 inches long and 90 inches wide. How can the carpet be cut into two pieces of equal sides and shape to cover an area of 100inches? There can only be one cut and no scraps. Please show me how. Answered by Penny Nom.
	.400 in Baseball		1999-12-15
		From Nieve Nielson: I have several questions to ask about the probability of getting a .400 in baseball: What is the probability of a baseball player hitting a .400 in one game, considering that the hitter is up to bat four times? What is the probability of a baseball player hitting a .400 in a season, considering that there are 100 games in a season? With the first two questions in mind: Considering that baseball has been around for about 100 years, about how many people should hit .400 inthat time? Answered by Chris Fisher.
	Fibonacci Numbers		1999-12-15
		From Gary Nelb: I'm doing a project on fibonacci numbers and I'm using different starting values and finding out if different starting values to see whether or not the ratios still get closer to phi. I was wondering, what numbers should I use. Should I use two of the same # like 2 and 2, or numbers like 1 and 2, or even something totally different. Answered by Denis Hanson.
	Two calculus problems		1999-12-13
		From Alan: I have 2 questions that are very new to me, they were included on a quiz and the material was never covered. Our teacher never explained the purpose and detailed explanation of how to solve the problem. Could you help? Thanks. Question 1: A ball is falling 30 feet from a light that is 50 feet high. After 1 sec. How fast is the shadow of the ball moving towards the light post. Note that a ball moves according to the formula S=16t^2 Question 2: How many trapezoids must one use in order for the error to be less than 10^-8 if we want to find the area under the curve Y=1/X from 1 to 2. Find the exact area, Graph the function and use the trap rule for the "N" that you found. Answered by Harley Weston.
	Passing trains		1999-12-10
		From Nancy: Two trains, each of 80 cars, must pass on a single track which has a deadend siding. How can they pass if the siding can only hold a locomotive and 40 cars? I do not understand this...help. It will be due monday. I thought it would be simple if the siding could hold 80 cars. Answered by Penny Nom.
	Sines & cosine laws		1999-12-10
		From Pierre Boivin: Triangle LMN, angle L=71 degree , LM= 7.2 , MN=8.3 , ln= 5.9 The questiion was to find angle M. Using the cosine law I found the answer to be 44 degree. It is also the book answer. Using the sines law I found the answer to be 42.2 degree. why can't I use the sines law. Answered by Chris Fisher.
	Cubic meters to gallons		1999-12-09
		From Chris Compton: I am trying to convert cubic meters to gallons. Do you have the conversion formula? The problem I am trying to solve is: 59.62 cubic meters to gallons. Answered by Harley Weston.
	Solve for v		1999-12-09
		From Beth: 1-3/4(v+2)=-5 Answered by Penny Nom.
	A calculus problem		1999-12-08
		From JT Wilkins: These are the questions: Show that there exists a unique function that meets the following requirements: a) f is differentiable everywhere b) f(0)= f'(0)= 0 c) f(x+y)= f(x)+ f(y), for all real values of x,y Consider the function F: R-->R (All Reals) F(x) = 0, for x irrational & 1/q, x=p/q gcd(p,q)=1 q > 0 a)determine the values x where f is continuous, respectively discontinuous. b)determine the values x when f is differentiable and for each of these values compute f'(x). Answered by Penny Nom.
	Percentage change		1999-12-08
		From Michael Weinberg: I am the Laboratory information system supervisor in a hospital. Our computer system calculates the change of specific results to monitor a patient's status. But there is a problem with the calculation in the base code of the program. If one day the patient has a Blood count of 100 (P for Previous) then the next day the Blood count is 75 (C for current), the computer should calculate the change as -25% using the calculation |P-C|/P= D (D for Delta) and then check for positive or negative by the equation If P>C then D*-1 or If P The program is calculating using the equation: ((P/C)-1)*100 in the above situation this would calculate the Delta as 33.33333% Referenced in a Laboratory manual published before computers were used to calculate the delta changes. . . . Answered by Penny Nom.
	Advanced Calculus		1999-12-07
		From Kay: Hi, my name is Kay. Please help---these problems are driving me crazzzzy!!!! Your help would be greatly appreciated! Let a,b be contained in R, a . . . Answered by Claude Tardif.
	Inequalities and absolute values		1999-12-07
		From Austin Cline: Solve for x: The absolute value of x-1 is less than or equal to the absolute value of x-2 Answered by Harley Weston.
	Mean, median and mode		1999-12-07
		From J William Morning: Using the data values 2,2,10,6,5, determine the median, mode and mean. Answered by Penny Nom.
	Two conics		1999-12-07
		From Quinn: I know the formula to find the axis of symmetry of a conic section (I'm not sure what shape - circle for the first one??) is (-D/2A,-E/2C) but I obviously don't get how to calculate it, because when I check the answer it's wrong, but I'm so close!! For the following equations my teacher suggested to "divide the x term coefficient, D, by the x squared term coefficient before...do the same for y." 2x2+2y2-8x+12y+16=0 . . . Answered by Penny Nom.
	Bases other than 10		1999-12-06
		From Garret Magin: We are doing a lesson on numbers of other bases than 10. We are working with binary, octal, and Hexadecimal. I was wondering what is used to represent number of different bases other then 16? Does it just continue on with the alphabet and if so what happens when you get to Z. It would be a help if you could answer this because it is really bugging me. And none of the math teachers at my school could let me know. Answered by Claude Tardif and Patrick Maidorn.
	Systems of equations		1999-12-06
		From Roger Hornbaker: I am having problem figuring out x and y solutions. 5x + y = 4 3x - y = 4 3x + 2y = 6 - 3x + y = 0 Answered by Penny Nom.
	order 4+ determinants		1999-12-06
		From Joe Kron: Why is it never shown how to calculate the value of 4x4 (or larger size) deteminants by the diagonal multiply methods that are generally shown for 2x2 and 3x3 determinants? The method I'm talking about is called Cramer's Rule??? Is this method not extensible to order 4+ and if not why not? Anyway the method always shown for order 4+ is called "reduction by minors" which is not the answer to this question. Answered by Walter Whiteley.
	How many 3/5 are in 3/4?		1999-12-06
		From Whiteny: How many 3/5 are in 3/4? Answered by Penny Nom.
	Volume of an ellipsoid		1999-12-06
		From Michael Nowicki: I am a physician at the University of Mississippi. I am trying to compare the size of polyps (abnormal growth of tissue in the colon) between 2 groups of individuals. The department of pathology gives the size as length X width X depth - how do I calculate the volume? Polyps are nearly ovoid in shape. Answered by Walter Whiteley.
	Multinomial coefficients		1999-12-03
		From Suraj Das: Is there a formula for the expansion of (a+b+c) to the nth power? Does it have to do with Pascal's triangle? Answered by Penny Nom.
	The chain rule		1999-12-03
		From Jennifer Stanley: This problem is making me dizzy. I would greatly appreciate a little help! Express the derivative dy/dx in terms of x. y=u^2(u-u^4)^3 and u=1/x^2 Answered by Harley Weston.
	Log Cancel		1999-12-03
		From Justin Murray: Ok I feel like a goof because I know this and I cant think of an answer But I want to isolate the x in the function y=2^x how do I do this? Answered by Harley Weston.
	Whole numbers		1999-12-02
		From Patty: I'm in a 5th grade class, please explaine what whole numbers are..... Answered by Penny Nom.
	The elimination method		1999-12-02
		From Jennifer: Could I get an answer to this one: 2x+5y=36 3x+2y=32 I have to use the Elimination method, as I already know how to do Substitution. How do I begin and show my work? I'm attempting to eliminate the values for y. Answered by Penny Nom.
	Zero to the zero		1999-12-02
		From A middle school teacher: I am a middle school teacher who is looking for a precise explanation of why zero raised to the zero power is undefined. I am hoping to get an explanation using something other than the fact that diividing by zero is undefined. Answered by Penny Nom.
	Camels and bananas		1999-12-02
		From Marie Rich: Corey Camel's harvest, worth its weight in gold, consists of 3000 bananas. The market place where the stash can be cashed in is 1000 miles away. However, Corey must walk to the market, and can only carry up to 1000 bananas at a time. Furthermore, being a camel, Corey eats one banana during each and every mile she walks (so Corey can never walk anywhere without bananas). How many bananas can Corey get to the market? Answered by Claude Tardif.
	Get rich quick		1999-12-02
		From Holly Hutson: If one cent were placed in an investment that doubles in value every day, what would be the value of the investment at the end of 30 days? Answered by Penny Nom.
	Two calculus problems		1999-12-01
		From O'Sullivan: Question #1 Assume that a snowball melts so that its volume decreases at a rate proportional to its surface area. If it takes three hours for the snowball to decrease to half its original volume, how much longer will it take for the snowball to melt completely? It's under the chain rule section of differentiation if that any help. I've set up a ratio and tried to find the constant but am stuck. Question #2 The figure shows a lamp located three units to the right of the y-axis and a shadow created by the elliptical region x^2 + 4y^2 < or= 5. If the point (-5,0) is on the edge of the shadow, how far above the x axis is the lamp located? The picture shows an x and y axis with only the points -5 and 3 written on the x axis. the lamp is on the upper right quadrant shining down diagonally to the left. There's an ellipse around the origin creating the shadow. It's formula is given as x^2 + 4y^2=5. Answered by Harley Weston.
	Cos x = -1/2		1999-12-01
		From Pierre Boivin: When I factor[ 2cos (square) - 5cos -3], I get (2cos + 1)(cos - 3). 2cos + 1 = 0, 2cos = -1, cos = -0.5,. Using inv cos on calculator, I get 120 degree related angle. When I graph I get two values, between 90 and 180 degree and between 180 and 270 degrees. How do I find those two values. How do use 120 degree in relation with the x axis. Answered by Penny Nom.
	An area problem		1999-11-29
		From Vicky Birch: The length of a rectangle is three times it's breadth. If the length were 6 meters less, and the breadth were 6 meters more, the rectangle would be a square. Make a mathematical model and solve the resulting equation to find the breadth of the original rectangle. What is the area of the square? Answered by Penny Nom.
	Two candles		1999-11-24
		From Skip Simpson: You have two candles the same length. They are lit at the same time. One burns down in 4 hours; the other in 5 hours. How long does it take before one candle is three times the length of the other candle? Answered by Walter Whiteley.
	The number of city blocks in a country mile		1999-11-24
		From Gloria Hearst: For years my family has had an on going debate on the number of city blocks in a country mile. We vary from a minmum 8 blocks per mile to a maximum of 12 blocks per mile. Answered by Nadine Griffiths and Penny Nom.
	How wide is the well?		1999-11-24
		From Chris Baranski: There is a well and in the well there are 2 sticks one is 2 meters long the other is 3 meters long and they are opposite to each other. They are leaning against the wall of the well. The place where they touch is 1 meter of the bottom of the well. How wide is the well? Answered by Chris Fisher.
	Repeating decimals		1999-11-22
		From Andrew: Is 1.9 repeating the same as 2? Answered by Walter Whiteley.
	Age in minutes		1999-11-21
		From Mesha Jackson: How old would I be in minutes if I were 12 Answered by Penny Nom.
	A goofy clock		1999-11-20
		From Kate: While repairing a watch, a jeweler removed the hands and inadvertently replaced the hour hand on the min. spindle and vice versa. he set the hands to read 2:00pm, which was the correct local time when I picked up the watch. A few minutes later, I noticed that the hands were taking goofy positions. What was the first time thereafter that the watch would show the correct local time? Answered by Chris Fisher.
	A matching quiz		1999-11-20
		From William J. Ricciardi: I gave a matching quiz the other day and one of my students got all 9 incorrect. That got me thinking......What is the probability that someone could get all 9 questions incorrect? Answered by Peny Nom.
	Selecting some players		1999-11-20
		From Korbin Brown: Roger Craig, during his term as team manager of the San Francisco Giants, received a strange communication from the team general manager, Al Rosen. Mr. Rosen told him to select 25 players according to this formula: 1/2 of the team had to be outfielders and infielders 1/4 of the team had to be starting pitchers 1/6 of the team had to be relief pitchers 1/8 of the team had to be catchers Roger was a bit confused by Al's request, yet complied anyway. How did he do it? Answered by Claude Tardif.
	Ratios and proportions		1999-11-19
		From Rebecca: I'm not that good of a student and I was woundering if there is a shortcut to ratios and proportion. My 6th grade teach tought all we needed to know. I was just wounder if there was an easier way. Answered by Claude Tardif and Harley Weston.
	Area of a quadrilateral		1999-11-19
		From Zane Cram: I need the formula to calculate the area of an irregular sided rectangle. Each side has a different measurement or length. Answered by Walter Whiteley.
	polynomial functions		1999-11-19
		From Quinn: Without fully factoring the following show that they all have the same zeros: I: x4-x2+2x+6 II: -x4+x2-2x-6 III: -4x4+4x2-8x-24 IV: 10x4-10x2+20x+60 When P(x)=x3-3x2+5x+1 and G(x)=x3-2x2-x+10 are each divided by(x-a) the remainders are equal. At what coordinate point does the graph of P(x) intersect G(x)? Answered by Walter Whiteley.
	Critical numbers		1999-11-17
		From Sarah: My question is this: If f(x)=2x3+4x2-9x+8 and the derivative is f'(x)=6x2+8x-9, how do I find the critical points if f'(x) is not factorable?? Answered by Penny Nom.
	Percent		1999-11-16
		From Elaine Edwards: Can you please tell me what is 75% of $495.00? Answered by Penny Nom.
	Two derivatives		1999-11-16
		From Gina Renicker: The derivative of: y=e(xlnx) and y=x2arctan(x1/2) Answered by Harley Weston.
	The sixth game		1999-11-16
		From Stephanie Sprunger: Janice scored 18,21,27,16,and 19 points in five basketball games. How many points must she score in the next game to raise her average to 22 points per game? Answered by Penny Nom.
	Domain and Range of a Function		1999-11-14
		From Michelle Mellott: How do you find the range of the following function: 2y2/(y2+5y+6)?? I know the domain is x not equalled to -2, -3. How can one easily find the range? Answered by Harley Weston.
	Estimating the population mean		1999-11-13
		From John Barekman: Statitistics: Estimating the population mean when the standard deviation is known: I am not sure which n to use in the formula for the confidence interval equation: x +/- z*(standard deviation/sqrt(n)) If we have data of ten people, and if we have the data of ten sets of ten people each, what is the difference in the n that we use? What is the difference between the standard deviation and the standard error? Are we using the number of sampling means or just the number of samples? Answered by Harley Weston.
	Number sequences		1999-11-11
		From Justin Schessler: I CAN NOT figure out this sequence or how we continue this sequence... 3,2,6,5,15,14,___,___,___ Answered by Chris Fisher and Harley Weston.
	Body part measurements		1999-11-10
		From V Bailey: I am a kindergarten teacher and mother of a 6th grader who wants to do a science project on the correlations of body part measurements. We heard this on the radio and it sparked our interest, but now I cannot find any information about it. Examples are: your height is supposed to equal the distance from fingertip to fingertip when your arms are outstretched. Your foot size is supposed to equal the distance from your wrist to your elbow. Please help me find more information on this topic. Answered by Penny Nom.
	Linear models		1999-11-09
		From Helen Moreno: What is a linear model? Answered by Harley Weston.
	Multiple step problems		1999-11-09
		From Maria Rainsdon: I don't understand how to solve these multiple step problems. I wasn't there when my teacher explained it and I am really lost. Here is one of the probs I don't understand: 3m+6=-m-6. Answered by Penny Nom.
	Parabolic mirrors		1999-11-07
		From Andy White: I am working on a project concerning parabolic mirrors. I need to create a mirror to focus sunlight on a focal point, but I don't know how to do it. Is there some equation that tells where a focal point will be in relation to a parabola? What is a directrix? Answered by Penny Nom.
	Mean, median and mode		1999-11-06
		From Rick: I have five number places and the mean and median are both "0". The mode is greater than the mean. The sum of the absolute values of all of the numbers is 20. The smallest number is 4 less than the next smallest number. What are the five numbers. (negative integers can be used) All of the numbers are integers. Answered by Penny Nom.
	Crossing number		1999-11-06
		From Christian: The crossing number of a graph G, denoted cr(G) is defined to be the minimum number of (pairwise) crossings of edges among all drawings of the graph in the plane. For example, cr(K5)=1 and cr(K3,3)=1. What is cr(K7,7)? I figured out that the answer is 81. Now I am trying to figure out if K7,7 can be drawn in the plane with less than 81 crossings? I'm not sure how to approach this one. Other than actually drawing it out and checking by trial and error, I am not sure how to approach this problem. Please help! Answered by Denis Hanson.
	Division/Fractions		1999-11-06
		From Azmat Hussain: Is there a way to explain division by fractions using patterns? For example 3 divided by one half. Answered by Chris Fisher and Penny Nom.
	Nines and ones		1999-11-05
		From Greg Miller: Using the numbers 1, 1, 9, 9, only once each, how can I create an expression that equals 10 using only the basic functions of addition, subtraction, multiplication, division, and/or parentheses? Answered by Claude Tardif.
	Three numbers		1999-11-03
		From Walter: Three whole numbers , when added two at a time,yield the sums 75, 111, and 128. Find the smallest of these three whole #'s. Answered by Penny Nom.
	Transforming a triangle		1999-11-02
		From Wilder Maldonado: The height, H, of a triangle is increased by a lenth M, How much must be subtracted from the corresponding base,b, so that the area of the new triangle is one-half that of the original triangle. Answered by Penny Nom.
	Trolls and Gargoyles		1999-11-02
		From TexGrimm: How can you seat 6 monsters - 3 Trolls and 3 Gargoyles- at a circular table if the trolls look alike and the gargoyles look alike? Does your formula work for 9 monsters - 4 trolls and 5 gargoyles? Answered by Penny Nom.
	Inverses of functions		1999-11-01
		From Leanne Hickey: Let f(x) = 2x2 -3x + 2. Find f-1(4) given the fact that f(2) = 4. So the question is finding the inverse of 4, he said it's easier than it looks. Answered by Penny Nom.
	Powers of zero		1999-10-31
		From Salina Young: Hello! I have two questions to ask about the power of "0". First, what is the value of "0' to the power of "0"? And why? Second, what is the value of "0" to the power of "2" or '3" etc? And why? Thank you for your help. Answered by Walter Whiteley and Harley Weston.
	Area of a circle and an inequality		1999-10-30
		From Adam Anderson: I have two problems. The first: prove that the area of a cirlce is pi times radius squared without using calculus. The second: show that ln(x) < x - 1 for all x > 0. Answered by Harley Weston.
	A pictograph		1999-10-28
		From Ali: Please tell me how to make a pictograph.I am 2 grade student. Answered by Penny Nom.
	Ben's observation		1999-10-28
		From Emily Nghiem and Ben Rose: As a teacher at a school called Educere in Houston, I have a ninth-grade student who discovered the following shortcut last year as an eight-grader. What he noticed is that given any two consecutive integers (or n and n+1 for any rational number greater than or equal to 2), the difference between their squares was equal to the sum of the two numbers. . . Answered by Chris Fisher and Penny Nom.
	Calculating a square root		1999-10-28
		From Jonathan: What is the formula for calculating a square root? Answered by Penny Nom.
	Clockwise or Counterclockwise?		1999-10-27
		From Tim: A particle moves around the circle x2 + y2 = 1 with an x-velocity component dx/dt = y Find dy/dt Does the particle travel clockwise or counterclockwise around the circle? Why? Answered by Harley Weston.
	Derivatives with logs		1999-10-26
		From Kate: What is the derivative of 5 to the 5x-2 at x equals 0.8? Answered by Harley Weston.
	Order of operations		1999-10-25
		From Garrett: 99*(57+76)*9-1085/9 Answered by Penny Nom.
	-log(a)		1999-10-22
		From Brenda Miskimmin: I need to know the mercury concentration in mg/L or ng/L for the following: -log M (Hg) = 8.5 where mw of Hg=200.59 (it's the negative sign in front of log that confuses me). Answered by Harley Weston.
	An odd number of factors		1999-10-22
		From Melissa: What is the common name used for numbers that have an odd number of factors? What is the least positive integer that has exactly 13 factors? Answered by Penny Nom.
	Cutting a board into 8 equal pieces		1999-10-21
		From Brittany: Jamie wanted a board cut into 8 equal pieces. The Lucas Lumber Co. charges 60 cents for cutting a board into 4 equal pieces. How much will it charge for cutting Jamie's board? Answered by Claude Tardif.
	0! + 1! + 2! + 3! + ... + 2000!		1999-10-21
		From Melissa: My name is melissa. I am a 9th grade student I am having trouble finding out how to do this: What is the tens digit of 0! + 1! + 2! + 3! + ... + 2000! I know how to find these, but my calculator cant go any higher than 69! Is there any way i can do this problem? Answered by Penny Nom.
	Going to the movies		1999-10-21
		From Gayla Werry: You have $1.00 to take 100 people to the movies. It costs: 1 cent for 10 children, 3 cents for each woman, 5 cents for each man. You have to take at least one of each category of people. Your answer has to add up to exactly 100 people and exactly $1.00. How many men, women, and children can you take? Answered by Penny Nom.
	|6-2x|<4		1999-10-20
		From Tchilco: Solve |6-2x|<4 Answered by Harley Weston.
	Piecewise functions.		1999-10-20
		From Jenny: How do you figure out a piecewise function by hand? e.x. ( 2x (if x is not equal to 0) f(x)=< ( 0 (if x is not equal to 0) Answered by Harley Weston.
	How many squares are on a chessboard?		1999-10-20
		From Tchilco: How many squares are on a chessboard? Answered by Penny Nom and Claude Tardif.
	Broken line graphs		1999-10-19
		From Lori Samara, Kristi Cameron and the 4th grade students: Students in Ms. Cameron's grade 4 class were wondering if a broken line can be used anywhere in the range on the y - axis when creating a broken line graph? They understand that the broken line can be used at the 0 on the broken line but what if there is a large gap in the data from 100 - 200? What do we do? The text book and mathematics dictionary do not answer these questions. Answered by Penny Nom.
	l'Hospital's Rule		1999-10-18
		From Yannick Gigandet: How can I solve these two limits : lim when n approches 1 of n[a1/n -1] lim when x approches 0 of (eax - ebx) / x Thanks for the answer! Answered by Harley Weston.
	Working Backwards		1999-10-16
		From Linda: I am having problems finding examples of problems that require "Working Backwards" used as a strategy for solving. We are required to give a presentation on Monday, October 25, 1999 in our school districts math class. We are trying to become better problem solvers and how to teach problem solving in the elementary classroom. Help! I can't find anything in my web searches. Answered by Penny Nom.
	An equivalent decimal		1999-10-14
		From Cheryl Wendlandt: I have a question in my book that is one and five sixths and you are to put them in an equivalent decimal. I'm sick at home or I would be able to ask my instructor. I would appreciate any help. Answered by Penny Nom.
	(-5)^2, -5^2 and -(5)^2		1999-10-13
		From Jennifer Brown: What is the difference between the following problems: (-5)2, -52 and -(5)2 Our text book (Beginning Algebra, fourth edition, published by McGraw Hill, by Streeter, Huthison and Hoetzle) says the second and third problem are exactly the same. I don't see how that can be. Is there a mathematical rule that explains this? Answered by Penny Nom.
	Find the missing numbers		1999-10-12
		From Bonnie: I must find the missing numbers and function rules n output 7 10 12 20 39 40 24 30 16 b 87 c we are totally confused can someone help Answered by Denis Hanson.
	A famous mathematician		1999-10-12
		From Yvette Perez: Another way to write 3/15. Remove 0 add a line, unscramble, you have the name of a famous mathematician. Answered by Claude Tardif.
	Isosceles triangles		1999-10-12
		From Amber: In defining the types of triangles, our class was stumped by a question asked by one of the student. Maybe you could help. The definition of an equilateral triangle is a triangle with three congruent sides. The definiton of an isosceles triangle is a triangle with at LEAST two congruent sides. The question is, if an isosceles triangle only requires at Least two of the sides to be congruent, could an equilateral triangle be called an isosceles triangle? Answered by Penny Nom, Walter Whiteley and Chris Fisher.
	Solving using logs		1999-10-11
		From Rich Bolton: Here's my question: $541.39(1+i)15=784.09 Can you please show me how to do this? Answered by Penny Nom.
	Women in Trig		1999-10-11
		From Sandra Mills: I am looking for some information about women who have contributed to the discipline of trigonometry. In addition to this I have been asked to choose a subject pertaining to Roman times for my Roman and American Lit class. I wanted to do a project and presentation related to mathematics, but could use some suggestions-- maybe how mathematics were applied as in engineering and the structure of the Roman buildings. Could you please provide some information about the history of mathematics and it's applications in Roman times. I am also open to any other suggestions for topics. Answered by Chris Fisher.
	Equations with fractions		1999-10-10
		From Lori: I'm a secondary student. How would you figure out a problem such as t-2/t =14/3t - 1/3. The book gave one example but it is really easy. The work YOU have to do is totally different. You don't have to tell me the answer just how to do such problems like these. Answered by Penny Nom.
	Length of a line		1999-10-10
		From Dagmara Sarudi: My question has to do with the length of a diagonal. This problem came up when I thought about the shortest distance between two points, for example walking from one point to another in my neighborhood. I can choose a zig zag route and assuming the blocks I walk are exactly the same length, it shouldn't matter what route I took, the distance I travel should still be the same when I reached my goal. If, on the other hand I could travel in a diagonal line, the distance would be shorter. But what if, in my zig zag motion, the sections get so small the route approaches a diagonal. Shouldn't it be that each separate section added together equals the value of the two original sides? Or would it suddenly equal the value of the diagonal (which, of course was shorter than the two sides added together)? What gives? Answered by Chris Fisher and Harley Weston.
	Two Quadratics		1999-10-08
		From Jason On: Solve the following equations,expressing solutions in the form p + iq. sqr(x) + 2x - 1 = 0, sqr(x) + 2x - 3 = 0. Answered by Harley Weston.
	A sum of two squares		1999-10-08
		From Marksmen: what is the smallest whole number that can be written two ways as a sum of two different perfect squares? i.e.11squared plus 3 squared is 121+ 9=130 and7 squared + 9squared=49 +81= 130. Are there any smaller? I am stumped! Answered by Claude Tardif.
	sin x = x/10		1999-10-07
		From Amandeep Grover: Solve the equation sin x = x/10 Answered by Harley Weston.
	A trig limit		1999-10-06
		From Yannick Gigandet: What is the limit, as x approaches pi/3, of (1-2cosx) / sin(x-(pi/3)) ? Answered by Penny Nom.
	Palindrome		1999-10-06
		From Chris Ware: What is a non paladromic number? Answered by Claude Tardif.
	Logic and mathematical logic		1999-10-06
		From Polly Mackenzie: What is the difference between logic and math logic? Answered by Walter Whiteley.
	A googol		1999-10-06
		From Kevin Brennan: describe to me a guegoll is that how u spell it? it sounds like that Answered by Penny Nom.
	Common factors		1999-10-06
		From Tommygirl98: Ok I have a question about common factoring I'm not to sure if you could help me but it's worth a try here it goes. Ok I have a test on Friday and i'm having trouble understanding how to do it here's an example, Factor, -10 + 2b how do you do it and what do they mean by factor? Answered by Penny Nom.
	The circumference of a circle		1999-10-05
		From Mara Frost: what is the formula to find the circumference of a circle, or if there is no formula, how do you find the circumference of a circle? Answered by Penny Nom.
	towers of cubes		1999-10-05
		From Sanker: I need help to solve this Rules for bulding towers of cubes rule 1 The number of cubes on the bottom layer is always one less than the number of squares on the grid rule 2 Each new layer is made with one cube less than the layer underneath it. Investigate how many different arrangements there are of 4 cubes on top of 5 cubes on a two by three grid investigate the number of different arrangements of six cubes on top of seven cubes on a two by four grid investigate the relation between the number of arrangements of cubes and the size of the grid when there are two layers of cubes when there are more than two layers of cubes Answered by Walter Whiteley.
	Regular and irregular shapes		1999-10-03
		From Samuel Tighe: What is the difference between a regular shape and an irregular shape? Are a rectangle and a triangle regular or irregular shapes? Answered by Walter Whiteley.
	Percentage increase		1999-10-03
		From Ann Allen: I am a a student in the 12th grade. I need to know how to calclulate the following: A percentage increase from 2.0% to 9.5% is what percentage? Answered by Harley Weston.
	Two limits		1999-10-02
		From Jennifer: How do I find lim (1-cosx)/(x^2) as x-> 0 and lim (tan3x)/x as x->0 Answered by Harley Weston.
	A donkey and his carrots - part 2		1999-10-02
		From Sarah Klink and Brenda Gamble: Does anyone know the solution of the donkey who had to carry 3000 carrots to the market which was 1000 miles away? The donkey can only carry 1000 carrots at a time and he eats one carrot every mile he walks but this is only when he is carrying carrots. How many carrots can get to the market with the donkey carrying them? Answered by Claude Tardif.
	Temperatures		1999-09-27
		From Eula: How do you cahnge farenheit degrees to celsius degrees? Answered by Penny Nom.
	Dollar Bills		1999-09-27
		From NRQT: Why are 1999 American dollar bills worth more than 1997 American dollars bills? This has to be put into a mathematical problem??? Answered by Penny Nom and Claude Tardif.
	Jose and Arthur		1999-09-26
		From Joel Hammer: Jose can run around the track in 40 seconds. Arthur runs with Jose but in the opposite direction. They meet every 15 second. How long will it take Arthur to make one trip around the track? Answered by Denis Hanson.
	Trigonometry history		1999-09-25
		From Nikki: What is trigonmetry ? Who invented it ? What is it's purpose ? And anything else that you can tell me that is related to Trigometry. Answered by Chris Fisher.
	Two 12-sided polygons		1999-09-25
		From Kelly Boulton: Two 12-sided polygons are similar. A side of the larger polygon is 3 times as long as the corresponding side of the smaller polygon. wHAT IS the ratio of the area of the larger polygon to the area of the smaller polygon. Answered by Walter Whiteley.
	Intercepts		1999-09-24
		From Cassandra: My book says to find where the X and Y intercept, i dont understand who to do this problem. Can you please help here is the problem. it didnt quite explain the instructions. Answered by Penny Nom.
	A fraction problem		1999-09-23
		From TruRed: Seven ninths divided by a negative 3.Could you pleas answer my question and go step by step. Answered by Penny Nom.
	Percentages		1999-09-23
		From Pete Cornejo: Hello, I was wondering if you could help me with a question? Yesterday my daughter came to me and asked if I could help her solve these three problems. 18 percent of 25 is what? 18 percent is what of 25? 25 is what percent of 18? Answered by Walter Whiteley.
	English to french maths words translators		1999-09-22
		From Steph Keeley: Can you foward be any information re English to french maths words translators, as i am having problems finding one. Answered by Penny Nom.
	-8*-(-5a)=15		1999-09-22
		From Shelby: -8*-(-5a)=15 i cannot get this question!! please help me!! Answered by Harley Weston.
	Predictions		1999-09-22
		From Joesph Dana: How do u find the results of an unbiased sample of 100 students that are shown on the table. For example the school has a total of 1,150 students prdict how many students would chose cereal(46) pancakes(15) eggs(20) and sandwich(19) Answered by Haeley Weston.
	Numbers with the digit 2 in 1...1000		1999-09-20
		From Jessica: Is there a trick to finding out how many numbers containing the digit two is there from 1 to 1000? Answered by Walter Whiteley.
	Distance between the windows		1999-09-19
		From Lawrence: An observer on level ground is at distance d from a building. The angles of elevation to the bottom of the windows on the second and third floors are a and b respectively. Find the distance h between the bottoms of the windows in terms of a b and d Answered by Harley Weston.
	Fractions, percents and decimals		1999-09-19
		From Sue Farr: My son is in 5th grade, and I can't seem to find any papers that have a simple explanation of how to convert decimals into fractions, percents into decimals, and vice-versa. Answered by Harley Weston.
	Magic Square		1999-09-18
		From Nick Grundberg: Using the this square, fill in the squares using the numbers 1 through 9 just once to make all the sums equal in all directions, across, down, and diagonally. Then tell what the sum of the magic square equals. Answered by Penny Nom.
	Repeating decimals		1999-09-18
		From Kavoos Bybordi: I dont know how to change a reccuring decimal to a fraction please could you tell me the method. Answered by Penny Nom.
	Surface area of a cone		1999-09-18
		From Frothy: I don't understand how to find the surface area of a cone. The height is 12cm and the radius is 5cm. Answered by Walter Whiteley.
	The greatest possible difference		1999-09-17
		From Denea Hugunin: Use each of the digits 1 to 5 once to make a 2 digit number and a three digit number that the greatest possible difference. Answered by Penny Nom.
	2 to the x and x squared		1999-09-17
		From John: For what values of x is 2 to the exponent x greater than x squared? Answered by Harely Weston.
	Square roots without a calculator		1999-09-14
		From Josh Weiner: Is there any way to find out a square root without a calculator? Answered by Harley Weston.
	Bob and his dad		1999-09-14
		From Yvette: "Bobs dad is 27 yrs older then Bob. The sum of their ages 5 yrs ago was 45 yrs. How old is Bob now?" Answered by Penny Nom.
	Stem and Leaf Plot		1999-09-14
		From Jeanette Sovick: My 5th grade son brought home a math paper, the title of which reads, Reading Stem-and-Leaf Plots...can you explain this so I can explain it to him...There is no book, his teacher just sent this practice sheet home for him to complete and I have no clue! Answered by Penny Nom.
	Six toothpicks		1999-09-14
		From Maddie: The book asks: Using 6 toothpicks represent the number 17. I am studying expressions to represent a number. ex.) (2+4)4x4=96. Answered by Penny Nom.
	Two Jugs		1999-09-14
		From Kynadi Kemp: If you have and 8 liter and a 3 liter jug and you want exactly 4 liters how do you get it if there is a water hose near by but thats all you have to get the 4 liters how do you do it ????? Answered by Penny Nom.
	Help with three mathematicans!		1999-09-14
		From Ashley Tacheira: I am a sophomore in high school and have been assigned a research paper on over thirty mathematicians. I was able to find information on all but three. I need to know the birth and death dates and major contributions of these three mathematicians. Any suggestions on where to look would be appreciated. George Stigler, T.C. Koopmans and Thomas Guthrie are the three that I cannot seem to find. Answered by Chris Fisher.
	Bales of hay		1999-09-13
		From Ivy: You are given 5 bales of hay. Two bales are weighed at a time, which equal the following weights: 110, 112, 113,114,115,116,117,118,120,121. What does each individual bale weigh? Answered by Harley Weston.
	Inductive reasoning pattern		1999-09-13
		From Greg Walsh: What are the next 2 rows of the pattern? 3 13 1113 3113 2123 112213 312213 Answered by Walter Whileley.
	Roman Numerals		1999-09-13
		From April: Write MCDXCVII in arabic numbers Answered by Penny Nom.
	Spreading a rumor		1999-09-13
		From Bornstar14: There is someone who wants to spread a rumor within 7 days to 250,000,000 people. he wants to know how many people he should tell on the first day (assuming the rumor is passed by everyone who was told to the same amount of people) so that everyone knows on the 7th day. What I did is the 7th root of 250,000,000. this answer is not possible unless rounded. is it okay for the number to be approximate? Answered by Penny Nom.
	Rolling Circles		1999-09-12
		From Craig Ellis: We have a circle of radius 3. inside the circle and tangent to the circle of radius 3 at one point is a circleof radius 1. The question is if we could roll the smaller circle around the inside of the larger circle how many revolutions would it take to get around to where we started. Answered by Chris Fisher and Walter Whiteley.
	2,5,8,1 yields 24		1999-09-12
		From Terry Hill: I was wondering how do I make the numbers 2,5,8,and 1 equal 24? Answered by Penny Nom.
	How many went to the game?		1999-09-09
		From Lisa Schmidt: If 3/4 more students went to the game than actually did go to the game, 25% of all students in the entire school would have gone. What fraction of students in the entire school went to the game? Answered by Harley Weston.
	Degrees and triangles		1999-09-09
		From Sandra Mills: Are there any triangles which are not 180 degrees? I am also in need of information on the history of degree measure for an angle. Answered by Walter Whiteley.
	Four fours		1999-09-09
		From Roger: I need help with a math problem my child asked me about I guess in her 7th grade math class they were told to come up with a answer from 1-10 only using four 4's and she got stuck on the problem that needs to be equal to ten, she asked me and I couldn't help her it's sad so if you could give me the problem and and answer so i could explain it to her I would really appreciate it. Answered by Penny Nom.
	Using Factoring in Problem Solving		1999-09-09
		From Lori: I have a problem with a problem. The Problem is....The sum of the squares of two consecutive positive even integers is 340. Find the integers. Answered by Penny Nom.
	Infinity		1999-09-08
		From Richard Tracy: In order to transverse from point A to point B one must first cross the halfway point (C). Additionally....One must also pass another halfway point labeled (D) in order to get to the halfway point of (C). There is also point (E) which is the halfway point between A and D. We have to assume that there are an infinite amount of halfway points points between (A) and (B). My understanding of infinity is something that goes on forever. But how can one expect to traverse over infinity in a finite amount of time? Will we never reach (B)? Answered by Walter Whiteley.
	Who is right		1999-09-04
		From rf, k, p and uncle a: Good morning. Could you please, help us resolve and by the way, confirm "who is right"... regarding the solution of this problem: - a piece of metal is 6 in. wide by 2 in. in height and weights 500 pounds... - what is the weight of a piece made of same metal, 5 in. wide by 1 3/4 in in height? Could you please supply the "formula". Regards, rf, k, p and uncle a. Answered by Penny Nom.
	Towers of Hanoi		1999-09-03
		From Jeni: In the puzzle called the Towers of Hanoi there are three peg and you are asked to move the rings from one peg and stack them in order on another peg. You can make as many moves as you want, but each move must consist of moving exactly one ring. Moreover, no ring may be placed on top of a smaller ring. The minimum number of moves required to move n rings is 1 for 1, 3 for 2 rings, 7 for 3 rings, 15 for 4 rings, and 31 for 5 rings. Find a formula for this sequence. What is the minimum number of moves required to move 6 rings? Answered by Penny Nom.
	Is zero positive?		1999-09-03
		From Shah: Is zero a positive integer? Answered by Penny Nom.
	Y2K?		1999-09-03
		From Mike Putzakulish: In Y2K, the "K" stands for thousand, but where did the "K" come from? I know it's not a Roman Numeral, but what is it?? Answered by Chris Fisher and Harley Weston.
	Notation		1999-09-03
		From Judy Gray: My name is Judy Gray. I guess the level on this would be about middle school, and I am an other!! I've been out of school for alot of years. I have a couple of questions, I guess. What does an equal (=) with a slash through it mean? I put intersects, but I think I'm wrong. What is the symbol of a small n? Only the symbol is wider. Example: If A = {1.2} B = {2,3} then what is A (n) B? Can you make sense out of that? What is the equation of the y-axis? Answered by Penny Nom.
	The three jugs problem		1999-09-02
		From Kent Lane: I wonder if you could help me figure out this secondary Discrete Math Problem. I cannot figure out where this comes from. Here's the question: You have three containers. Container 1 is a three (3) liter container. Container 2 is a five (5) liter container. Container 3 is an eight (8) liter container that is full of liquid. The goal is to get 4 liters in one of the containers. Stipulations: There are no marks on the containers to measure out the liquid. All you know is that 1 is 3 l., 2 is 5 l., and 3 is 8 l. full of liquid. Answered by Chris Fisher.
	Division by zero		1999-09-02
		From Joshua B. Mariano: Why can't I divide a number by zero. When I put in my calculater 0 divided by 7 it equals 0. But when I put 7 divided by zero my calculater say's error. Why can't this be solved? What is the answer? Is there a paper on it? Help? Answered by Walter Whiteley.
	A double negative		1999-09-01
		From Dennis: If b = -2 what does -b = ? As in (a + 8.5) - [(-b) + |c|] a = 1.5, c = -1.7 Answered by Penny Nom.
	A Multiple Choice Test		1999-08-31
		From Cintra Ramnarine: I have ten questions. There are two multiple choice answers to each question. What are the chances of answering all questions correctly. Answered by Harley Weston.
	Intercepts		1999-08-29
		From Sally Rickerson: I am looking for any intecepts. How do I solve: y=x^2 square root of (9-x^2) Answered by Harley Weston.
	The Bellhop Problem		1999-08-29
		From Gerard O'Neill: Three fellows going to a Math Conference book into a motel. "That will be $30.00" says the bellhop. Each fellow gives $10.00 and they go off to their room. The manager enters and says "That was a $25.00 room. Go and give them $5.00 back." The bellhop heads off but thinks....."how am I going to split $5.00 between 3 fellows? Hey I will keep two dollars and give each guy a dollar." He does just that.......each fellow now paid $9.00 and the bellhop kept two. 3 X 9= 27 plus the bellhops two = $29.00 Where is the missing dollar? Answered by Harley Weston.
	A Trigonometry Question		1999-08-28
		From Diane Simms: My question is can the following be factored. I am a teacher who needs the factors to this right away. 2 Sin2X + 2 SinX CosX - 1= 0 Answered by Harley Weston.
	Invert and multiply		1999-08-28
		From Debbie Walter: I have another question please, WHY do we invert and multiply when dividing fractions? I know that's what we do but WHY? What is the reasoning behind it? Answered by Penny Nom.
	Crossing the Bridge		1999-08-27
		From Debbie Walter: If you have four people who need to cross a bridge in the dark with only one flashlight and only two of them can cross at a time and their speeds of crossing are as follows: one person can cross it in one minute one person can cross it in two minutes one person can cross it in five minutes and the slowest person can cross it in ten minutes what is the shortest amount of time it would take to get all four across the bridge? Answered by Penny Nom.
	The sum of the cubes is the square of the sum		1999-08-25
		From Bernard Yuen: How to prove 13 + 23 + 33 + 43 + ... n3 is equal to (1+2+3+...n)2? (for n is positive integer) Answered by Harley Weston.
	A gazillion		1999-08-21
		From Leah: Does a gazillion really exist? Answered by Penny Nom.
	Division by a negative		1999-08-19
		From Sangeeta B.: 56/-8 Answered by Penny Nom.
	Why is slope designated m?		1999-08-18
		From Peter Komlos: Why is the slope of a line is designated by the letter "m"? Answered by Penny Nom.
	Perimeter		1999-08-15
		From Mel Nordan: The length of a rectangle is IS 3 1/2 times its width. Its perimeter is 108cm. Find its length and width. Choices for the width: 12,18,24 Answered by Penny Nom.
	111...1222...2		1999-08-11
		From Brad Goorman: Let N = 111...1222...2, where there are 1999 digits of 1 followed by 1999 digits of 2. Express N as the product of four integers, each of them greater than 1. Answered by Penny Nom.
	Parametric Equations		1999-08-06
		From Nicholas Lawton: Show that an equation of the normal to the curve with parametric equations x=ct y=c/t t not equal to 0, at the point (cp, c/p) is : y-c/p=xp^2-cp^3 Answered by Harley Weston.
	From an airport control tower		1999-08-04
		From Pammy: Hi I am a 30 yo mature age student doing my HSC but am having difficulty understanding this, if you can help me. From an airport control tower, a Cessna bears 023 degrees T and is 27km away. At the same time, a Boeing 767 bears 051 degrees T and is 61km from the tower. Both planes are at the same height. i) What is the size of angle ATB? ii) Using the cosine rule to calculate the distance the planes are apart, to nearest kilometre. I figured out and drew the triangular diagram but can't figure out the rest and which formula to use. sorry about this, thankyou kindly Answered by Harley Weston.
	Cognitive development as related to learning mathematics		1999-08-04
		From Chris Ahlman: I am doing an independent study for my Math theory course at Evergreen State College, WA. I am looking into teaching Math to elementary students "as a language". I need information on cognitive development to tie to this idea of language development. I only know of Piaget. There must be others who are more recent. Can you help? Answered by Walter Whiteley.
	Cleaning an Ellipse		1999-07-29
		From Mark Salter: Hello hope some one can help. We need to clean an elipse and then paint it. We need to know the square foot of the job and the job is an elipse which rises 2 ft. is 12 ft wide and is 36 ft long. Answered by Harley Weston.
	Geometry		1999-07-29
		From Jessica: How do you even do Geometry. Like what do you need to learn first and like a step by step plan.I realy need help I need it before school starts PLEASE!!!!!!!!! Answered by Walter Whiteley.
	A difference of squares problem.		1999-07-24
		From Michael and Stephanie Bixler: If you have the equation x= n2 - m2 (ie 40= 72-32= 49-9) x must = a positive number 1) which squared numbers work as n and m 2) how does it work 3) if my teacher gave me the number for x; how could I figure out this problem Answered by Harley Weston.
	A calculus problem		1999-07-22
		From Nicholas Lawton: The curve y= e^x(px^2+qx+r) is such that the tangents at x=1 and x=3 are parallel to the x-axis. the point (0,9) is on the curve. Find the values of p,q and r. Answered by Harley Weston.
	Infinity Symbol		1999-07-13
		From Mark E. Kelly: There is a symbol that looks like a sideways 8 that is used to represent infinity. Does it have a name? Answered by Doug Farenick and Penny Nom.
	Standard Deviation		1999-07-11
		From Anthony Fama: I have seen several answers to this question: If one standard deviation represents 68% of the population, what does two, three, four and five sigma [std deviation] represent? As stated, I have seen several different answers and thus, the impetus for my question. Answered by Harley Weston.
	The number of acres in a square mile		1999-07-09
		From Rita Murphy: What is the # of acres in square mile Answered by Harley Weston.
	An Acre.		1999-07-02
		From Walker Runnels: What is the outside measurements of an acre? (ie. x ft. X x ft.) Answered by Penny Nom.
	Compound Interest		1999-07-01
		From Kim Palmer: In early 1997, my son borrowed $4831 at 7.5%. He has made 30 monthly payments of $130 each. He is now in a position to pay off the balance. What is his remaining principal? Answered by Penny Nom.
	The shortest ladder		1999-06-26
		From Nicholas: A vertical wall, 2.7m high, runs parallel to the wall of a house and is at a horizontal distance of 6.4m from the house. An extending ladder is placed to rest on the top B of the wall with one end C against the house and the other end, A, resting on horizontal ground. The points A, B, and C are in a vertical plane at right angles to the wall and the ladder makes an angle@, where 0<@ Answered by Harley Weston.
	Scheduling Meetings		1999-06-25
		From Beth Carver: We have 6 groups meeting at three different places simultaneously. The meetings take place once a month each year. Is there a way to have each group meet with each of the other groups at least twice in a year, four times in each place? Answered by Chris Fisher and Harley Weston.
	Computer use in mathematics classrooms.		1999-06-23
		From Rosemary Greer: Can you give me any information, either articles or the names of books, concerning the use of computers in the math classroom? Answered by Lillian Perivolaris.
	Staying under budget.		1999-06-22
		From Chris: If I had $147.69 and I had to buy 200 bannas at $.46 & 100 potatos at $.42 each how do I stay under my buget Answered by Penny Nom.
	Sin 4A		1999-06-22
		From Ryan Cochrane: If sinA = 4/5, and A is a first quadrant angle, find sin4A Answered by Harley Weston.
	A Weighty Problem		1999-06-17
		From A parent: When using a balance scale, weights can be placed on either side of the scale. For example, if a 10 pound weight provides a counter balance to an object and a 7 pound weight, then the object must weigh 3 pounds. What four weights can be used to weigh objects of 1, 2, 3 ... 38, 39, 40 pounds? Answered by Penny Nom.
	Even and Odd Function		1999-06-17
		From Kent: There is one function with the domain of all real numbers that is both even and odd. Please give me the answer to this question before I go insane. Answered by Penny Nom.
	Liquid capacity		1999-06-15
		From Bernard Antill: Would you please tell me how many litres of water in a swimming pool that is 24 feet long, 16 feet wide & 4 feet deep. I would appreciate you showing the formula for this calculation. I am a 74 year old male and I cannot find a formula in which I have any faith! I would also appreciate the answer in Imperial gallons. Answered by Penny Nom.
	Slopes of curved lines		1999-06-09
		From Stephen Ehrler: When one plots the graphs of y=2x, y=3x, y=xx When each of these graphs pass through point (0,1) do they have the same slope? I know they are different lines but is it possable that they have the same slope at point (0,1). Answered by Harley Weston.
	Measuring the fourth dimension		1999-06-07
		From Suzanne Hall: Hi! The other day, two of my students asked a very interesting question: Is the fourth dimension measured with hypercubes? Their reasoning went like this: Lines are 1D and are measured with line segments, which are part of a line. Planes are 2D and are measured with squares, which are part of a plane. Space is 3D and is measured with cubes, which are part of space. So, logically, hypercubes would be used to measure the fourth dimension. Answered by Chris Fisher.
	A trig problem		1999-06-03
		From Stu Barnes: cos(theta) / 1+ sin(theta)=sec(theta)-tan(theta) I've being having trouble with this one on my correspondance course. Answered by Harley Weston.
	The three cousins		1999-06-01
		From Irena: I have three cousins on my dad's side. The product of their ages is 84. Next year the youngest will be 1/4 the age of the middle cousin. In 2 years from now, the oldest will be twice the current age of the middle. What is the age of my oldest cousin? Answered by Harley Weston.
	A problem with powers		1999-06-01
		From Bill: solve for the variable: 5-x = 25x+6 Answered by Penny Nom.
	How to carpet a room		1999-05-31
		From Appleby: A room which is 9X12 is to be covered with carpet but the carpet has been provided in one 8X1 piece and one 10X10 piece. The larger piece is to be cut into two pieces so that the room can be covered in carpet. Answered by Stacey Wagner.
	An Invalid Argument		1999-05-31
		From Rod Redding: Can an invalid argument have a true conclusion? If yes then why? Answered by Walter Whiteley.
	Graphing a linear equation		1999-05-27
		From Dylan Bradley: Im in Grade ten and am doing linear equations, I cann't figure out how to make a chart for questions like y = -2x + 3 Answered by Penny Nom.
	A circle in a square		1999-05-26
		From Jose V Peris: A circle is inscribed in a square. The circumference of the circle is increasing at a constant rate of 6 inches per second. As the circle expands, the square expands to maintain the condition of tangency. find the rate at which the perimeter of the square is increasing. find the rate of increase in the area enclosed between the circle and the square at the instant when the area of the circle is 25(pi) square inches. Answered by Harley Weston.
	Girth		1999-05-26
		From Carolyn Bulkley: I am trying to explain to my son (who is in the 8th grade) how to figure girth. I'm afraid I have just confused him. Is there a simply formula to figure the girth of a box. for example: I have a box that is 27" L X 22" W X 21" H. Answered by Penny Nom.
	Repeating decimals		1999-05-21
		From Stan: Hi, I am in Honors Math, and have confronted everyone, including teachers, about repeating decimals. What interests me is the number 0.9... and 1. Everyone says that since there is no number between 0.9...(repeating) and 1, that 0.9... = 1. However, isn't a repeating number a representation of a number, and not a real number? Let's look at it this way. 0.9 is close to 1. 0.99 is closer. 0.99999999999999 is even closer. so, 0.9... is a representation of it's closeness to 1. it's an active number... I don't understand how 0.9... is equal to 1. Please help me prove that 0.9... does NOT = 1. Answered by Penny Nom.
	Introductory Algebra		1999-05-19
		From Pat: (2 + sq. root of 3) x (2 - sq. root of 3) = 1 Please show me the work. Answered by Harley Weston.
	Three Daughters		1999-05-18
		From Norm Campbell: I recently received a beat up copy of the three daughters question. I have only some of the question. It ends after the statement "the oldest one looks....... It does not finish. Is there any chance that someone can finish it off for me? Answered by Rick Seaman and Harley Weston.
	Circles, cirmcuference and area		1999-05-16
		From Stephen Ehrler: I would appreciate if you could please tell me if what I discovered here is something or my ignorance? I noticed that a circle with r radii has the folling characteristic. r = [2 * ( pi * r2 / pi * 2r)] The equation states that the ratio of a circles area over its circumfrence = 1/2 that of the circles radii. It works every time. Did you know this ? Is it some kind of therom and can it be used for any thing? I thought this was intresting and would appreciate any input you may have. Thank you. Answered by Chris Fisher.
	Square feet and acres.		1999-05-15
		From Helene Freeman: How can I find out about acres in sq. ft. a house lot is 2360 sq. ft. and the house is on 1432 how many acres are left? Answered by Penny Nom.
	Re-Percentaging		1999-05-15
		From Doug Guion: My mind has gone blank. I have a series of percentages which have been establised by the same base number. I need to remove one of the percentages (13%) leaving me with 87%. I need to arifically inflate the remaining percentages to total 100%. Any help would be appreciated. Answered by Penny Nom.
	Related rates		1999-05-13
		From Tammy: The sides of a rectangle increase in such a way that dz/dt=1 and dx/dt=3*dy/dt. At the instant when x=4 and y=3, what is the value of dx/dt? (there is a picture of a rectangle with sides x and y, and they are connected by z, which cuts the rectangle in half) Answered by Harley Weston.
	Missing the boat		1999-05-11
		From Judith Moe: Our daughter is in Grade 3 and seems stubbornly determined NOT to learn how to add and subtract. She's been assessed as quite intelligent in reading and writing,...Do you know of any alternative approaches to teaching/learning math that are proving useful in such circumstances. Answered by Diane Hanson.
	A log problem		1999-05-08
		From N. Lam: I don't understand how to do this type of question: log(base absolute value x)y = log(base abs.val.x)2 + log(base abs.val.x)(Cos x) How do you graph the equation also, if -2(3.14)<=x<=2(3.14) Answered by Harley Weston.
	Base 2 to Base 10, conversion, convert		1999-05-08
		From Larry Bader: 101000112 is the same as what number in Base ten? a. 83 b. 128 c. 93 d. 326 e. 163 Answered by Penny Nom.
	Equivalence Relations		1999-05-06
		From Megan: I am tutoring a boy who got this assignment from his teacher and I have no clue how to do it because I don't even know what the questions is asking! I need some help. Hereit is: "Give five examples of relations which are not equivalent relations and five examples of equivalent relations and explain why they are equivalent relations." This is seventh grade and I read about it in his book but it is not coming together for me. Answered by Chris Fisher.
	A Polar Plot		1999-05-06
		From Irene: Consider the polar equation r=2-3Cos(theta/2) In the interval [o, 4Pi], how would you find the area of one of the leaves and also the length of one of the edges of a leaf? Answered by Harley Weston.
	48 cents with 6 coins		1999-05-05
		From Belinda: i'm in 5th grade. my teacher asked this question: what are two ways you can make 48 cents out of 6 coins? i could only figure out one way. please help. Answered by Chris Fisher.
	Evens and odds		1999-05-04
		From Emily Hays: My name is Emily Hays, I am in the 6th grade and my teacher gave me some extra probelms to see if I could solve them. She can't find the KEY and I can't figure out the probelm so she suggested I e-mail you guys to see if you could help us. Here's the Problem: The numbers 1,2,3...,1999 are written on the blackboard in the classroom. Evertime the teacher enters the room he chooses two numbers on the blackboard, say a & b, with a> or equal to b, then he erases them and writes the difference a-b somewhere on the blackboard. After this procedure is carried on 1998 times, there will be only one number left on the blackboard. Prove the last remaining number must be even. I hope you can help us! Answered by Chris Fisher and Harley Weston.
	The Jasper Project problem solving problem posting		1999-05-04
		From Heidi Laura Bergman: I am a pre-service teacher in my third semester (out of four) of student teaching at the University of Wisconsin - Madison. I am wondering if you can tell me anything about "The Jasper Project" or where I might be able to find out more information regarding this topic. Thanks, Heidi Answered by Rick Seaman.
	Shape-preserving transformations		1999-05-04
		From J McAndrew: A shape preserves its shape if a rotation, translation or scaling is performed on it. Are these the only continuous transformations which have this property? These transformations if performed on the parts and then summed have the same effect as the transformation being applied to the whole; are these linear transformations? Who, and what area of mathematics has classified all transformations of this type completely? Answered by Chris Fisher.
	Parabolic shapes		1999-05-04
		From Justin Ailor: Can you give me some parabolic shapes? Answered by Penny Nom.
	A		1999-05-02
		From Leah: a=b a^2=ab a^2+b^2=ab-b^2 (a-b)(a+b)=b(a-b) a+b=b b 2=1 why is this proof wrong? Answered by Penny Nom.
	A rhombicosidecahedron		1999-04-30
		From Himmat: What is a rhombicosidecahedron? Answered by Harley Weston.
	Roman Numerals		1999-04-29
		From Michelle Jenkinson: Someone proposed this question to me and I do not know the answer, so I was wondering if you could help. How, using Roman Numeral, did people add, subtract, multiply, and divide with no zero or negative numbers? Answered by Penny Nom.
	An equilateral triangle on a square		1999-04-26
		From Ed: My Grade 8 class and I were discussing the solution to the following problem: What is the area of the largest equilateral triangle that can be drawn on a 5 cm square. We used 5 cm as the base of our triangle and then drew the other two legs of 5 cm each to make the equilateral triangle. We then drew an altitude from the upper vertex to the base of the triangle. Using the law of Pythagoras with side a of 2.5 and side c of 5 we calculated side b to be 4.3 cm (the altitude). Therefore the area of the triangle would be 5 x 4.3 divided by 2 or 10.75 square cm. The answer key to this resource says I am wrong. What do you think? Have we interpreted the question incorrectly? Answered by Chris Fisher and Harley Weston.
	A bike race		1999-04-23
		From Bill Gepford: Bill was in a bike race and his friend kyle calculated that if he went 15mph that he would cross the noontime checkpoint one hour early but if he rode 10mph he would arrive one hour late. How far away is the checkpoint? Answered by Penny Nom.
	Question about 3rd degree polynomials		1999-04-23
		From Patrick Bryan: What is the general solution to the equation with the form: a*x^3 + b*x^2 + c*x + d = 0 I have once seen a solution to this a few years ago, but I do not recall if it was a general solution. What I do know, is that you could simplify this equation to: a*x'^3 + p*x' + q = 0... Answered by Doug Farenick.
	Parallel and perpendicular lines		1999-04-23
		From Crystal Pilling: My name is Crystal Pilling and I am in 9th grade algebra. We are currently studying parallel and perpendicular lines. I am having trouble with this problem: 3/4x - 5y= 16, (5,-6) I have to find a line that is perpindicular to this line on a graph. HELP ME PLEASE!!!!! Answered by Penny Nom.
	Bill and Sam at the Casino		1999-04-23
		From Rham Stewart: Bill and Sam went off to bet at the casino. Each started with the same number of dollars. At the end of the first hour, Bill had won 20$ and sam had lost 20$. At the end of the second hour, BIll had lost two thirds of his money, and Sam had won the same amount that Bill had lost. At that point, sam had four times as much money as BIll. How much did each one start with? Answered by Penny Nom.
	Radius of an arc		1999-04-22
		From Rusty Riddleberger: I need to find the equation for finding the radius of an arc; I know the length of the arc (i.e the distance of the line connecting the two ends of the arc) and the height; (i.e the rise of the arc at its apex,) I had the formula years ago but it has lost me; this would be invaluable for work in new homes i.e. where we need to build an "arch" with a rise of 21" between two columns 11 feet apart Answered by Chris Fisher.
	Shopping at Wegman's		1999-04-22
		From Stan: Joanne, Steve, Pat, Alice, Joan, and Bill go to Wegman's at the same time. Joanne buys 2 gal of milk, 1 dozen oranges, 8 apples, and 2 lb. of ground beef, paying a total of $13.24. Steve buys 3 qts. of milk, 5 lbs. of ground beef, 10 lb. of potatoes, and 2 bags of mixed vegetables, paying a total of $16.95. Pat buys 3 gal. of milk, 2 dozen oranges, 1 dozen apples, 5 lb. of potatoes, and 5 bags of mixed vegetables, paying a total of $25.09. .... Find the cost of: 1 qt. of milk, one orange, one apple one lb. of ground beef, one lb. of potatoes, and one bag of mixed vegetables. Answered by Penny Nom.
	A ladder problem		1999-04-22
		From Michael Blade: There is a cube box 3feet x 3feet x 3ft resting against a vertical wall on level ground. Resting against the outside corner of the box is a ladder 10 feet tall, this ladder is of course resting on the ground but also against the outside corner of the box and rests on the wall. The question- the ladder is divided into two unequal section bounded by the box to the ground and the box to the wall. what are those dimensions? Answered by Penny Nom.
	Area of a triangle from vertex coordinates		1999-04-21
		From Mark Tyler: I'm no schoolkid, but I liked your answers about triangles. You might enjoy a quick look at this, the kids may too. I was working on a Voronoi dual where I had to calculate the areas of very many triangles expressed as vertex coordinates, so I derived the following very direct formula: A = abs((x1-x2)*(y1-y3)-(y1-y2)*(x1-x3)) for triangle (x1,y1)(x2,y2)(x3,y3) I've never seen this in a textbook. Is it original? I doubt it, the proof is only a few lines long. Regardless, it may be fun for the kids, even if it's not on the curriculum. Answered by Walter Whitley.
	Radius of convergence		1999-04-21
		From Nowl Stave: Why is the radius of convergence of the first 6 terms of the power series expansion of x^(1/2) centered at 4 less than 6? Answered by Harley Weston.
	Circles		1999-04-21
		From Alex Elkins: How do you find the circumference of a circle if you only know the radius and the square feet or inches of the circle if the radius is 18 inches, If done in inches do you multiply by 12 to get the square feet? Answered by Jack Lesage and Harley Weston.
	The average rate of change of a function		1999-04-20
		From Tammy: Suppose that the average rate of change of a function f over the interval from x=3 to x=3+h is given by 5e^h-4cos(2h). what is f'(3)? I would appreciate any help with this question. Answered by Harley Weston.
	Unit conversions		1999-04-20
		From Deanna: My question has to do with unit conversions with English and metric systems. I need to know how to use conversion factors with powers of 10. Which way do i move my decimal point. ex. .48kl to liters. Thank you. Answered by Jack LeSage.
	A Series		1999-04-20
		From Deepak Shrestha: Given the sequence an=e^(-n*Ln(n)), does the series converge and why? Answered by Harley Weston.
	The halfway mark		1999-04-20
		From Sherry & Tom McGee: How do you figure the halfway mark between 1/3 and 2/3 as a fraction and a decimal point? Answered by Penny Nom.
	The birthday problem		1999-04-19
		From Gordon Cooke: How do I explain the rapid rise in the probability that at least two people in a group of n have the same birthday. We have derived the formula for p(n) and have graphed it and have seen how the results are counter-intuitive. At around n=23 p(n)=.5 and at n=50 p(n) is very close to 1. It does not help to simplify the problem (eg use months instead of days) because then our intuition does correspond more closely to reality. Is there some way we can see how the probabiltiy of a "collision" increases with n? It makes me think of data storage problems and hash tables in computer science. Answered by Harley Weston.
	Work jobs		1999-04-19
		From Cindy Miller: Hi. I'm a college student, majoring in Elementary Education. This semester I am taking a math class for elementary school teachers. I'm not sure if you can help out, but here is what I need. For the class, I am supposed to make 10 work jobs for students. Simple things that teach math that students can work on individually, for example after finishing a test. If you have any suggestions, I would really appreciate it. Answered by Penny Nom.
	Volume of oil in a tank		1999-04-17
		From Lars Waldemarsson: My problem is to get an equation for the depth of the oil in a gastank formed like a cylinder. The cylinder is in a horizontal position and by a stick you will be able to get the depth of the oil in the tank. All I need is an exmaple which I can build on. By this equation you will be able to get the volume of the oil if you know the depth. Answered by Harley Weston.
	Ounces and milliliters		1999-04-17
		From Tony Rizzi: I'm mixing a formula of: 48 oz distilled water. 15 grams of Hydroxy Ethyl Cellulose GR (powder) 30 grams of Hydroxy Ethyl Cellulose MR (powder) 200 grams of Barium Sulfate (powder) 1000 grams of Calcium Hydroxide (powder) After mixing, I need to estimate the amount of each ingredient that fits in a 3ml syringe. And how many syringes I can fill? Answered by Harley weston.
	y=mx+b		1999-04-15
		From Selena Royle: When solving a problem on slopes,and in the formula y=mx+b what do the M and B stand for? Why M and B? Answered by Penny Nom.
	Extra point questions		1999-04-15
		From W Troy Council: My teacher has given me 5 extra point questions. I have figured out two, but i need a little assistance with 3 others, could you help me with: A stablehand agreed to work for 1 year. At the end of that time, she was to receive $240 and one horse. After 7 months she quit the job, but still received the horse and $100. What was the value of the horse? If the roots of x2 + bx + c are pi and square root 2, then find "b" and "c." ... Answered by Penny Nom.
	The Binomial Theorem for rational exponents		1999-04-15
		From Angela Evans: The full question is this: Isaac Newton generalized the Binomial Theorem to rational exponents. That is, he derived series of expansions for such expressions as (x+y)-3 (x+y)2/3 (x+y)5/6 What did Newton find? What are the first four terms of the series expansions of binomials above? How can this extended Binomial Thrm. be used to aid in calculations? Answered by Penny Nom.
	Two contest problems		1999-04-14
		From Bruce Baldwin: We have students that are preparing for the Pythagoras Contest which is a nation wide Grade 6 math challenge. In the preparatory tests we have run into several questions that we can not understand. Is there anyone who can help us? If 1 * 9 = 0, 9 * 8 = 72, 2 * 8 = 9, then 9 * 9 = ? ... Answered by Judi McDonald and Walter Whiteley.
	Dividing a Circle		1999-04-12
		From Mike Kenedy: I am having trouble with a homework question for bonus marks. A Circle is continually divided by lines that do not intersect the center so that they produce the most pieces of circle. For example 1 line divides the circle into 2. 2 into 4. 3, however into 7. 4 into11 5 into 16 6 into 22 7 into 29 8 into 37 etc... I am stumped and cannot figure out the equation, though I'm sure it involves squares. Can you help? Answered by Penny Nom.
	Cross-sectional area of a cylinder		1999-04-12
		From Rebecca Connor: What is the formula to find the cross-sectional area of a cylinder? Answered by Chris Fisher.
	Linear programming and optimization		1999-04-09
		From Shams: What is Linear programming and optimization? Answered by Jack LeSage and Penny Nom.
	Grade 10 math		1999-04-08
		From Ron: the type of question i'm having trouble with is 5(2x-1)=3(x-4) Answered by Penny Nom.
	Dotted graph paper		1999-04-08
		From Bridget Winward: A teacher at our school is trying to locate dotted graph paper online or in print. His class would like to make three dimensional, geometerical drawings. Please let us know if you have a good source. Answered by Jack LeSage.
	Converting Metric Measurements		1999-04-08
		From Rick: Do you have any simple explanations for converting Metric measurements to other Metric measurements?? What helpful hints do you also have for a 5th Grader... Answered by Penny Nom.
	Universal Area		1999-04-08
		From Karen Richardson: I need a formula for area that works for a square, a rectangle, a parallelogram, a trapezoid, and a triangle. Answered by Jack LeSage, Chris Fisher and Harley Weston.
	Instant Winner		1999-04-07
		From FSSTAN: The probabilities of being an "instant winner" of $25 or $50 in a lottery are 1/600 and 1/1200, respectively. The mathematical expectation of being an "instant winner" of $25 or $50 is? Answered by Jack LeSage and Penny Nom.
	Area of an irregular shaped objects.		1999-04-07
		From Jesse Townsend: How do I find the surface area of an irregulary shaped object such as someone's knee from the thigh to shin? Thanks. Answered by Walter Whiteley.
	Large Numbers		1999-04-05
		From CK: Hello. I need a lesson plan for grades 4 to 7 dealing with the concept of large numbers. Specifically, how to teach scientific notation. The lesson plan has to deal with the following: the size of the universe is so huge that is is almost beyond the ability of the mind to comprehend. One way is to measure... Answered by Chris Fisher.
	Volume of a cube.		1999-04-04
		From Alex Elkins: How do you find the volume cubic matter of a cube or space, example how many cubic feet in an example 6" high 4' X 6' rectangle Thank You Answered by Penny Nom.
	Pi/4		1999-04-04
		From Daniela Annarella: What is the 30th digit of pi(1/4) after the decimal point? Answered by Harley Weston.
	T-shirts		1999-04-04
		From Valerie: At a discount T-shirt shop the manager marked a special batch of T-shirts that originally sold for $2.00. When all the shirts sold the shop had collected $603.77. How many shirts did they sell and what was the price per shirt? Answered by Jack LeSage and Penny Nom.
	Finding Excluded Values		1999-04-01
		From Lorraine Le Cam: The question asks me to find the value of the variable that must be excluded in each rational expressionion. The operation is: a ______ a - 2 How do I work this out? Answered by Harley Weston.
	Quadratic equations		1999-03-31
		From Ken Niebergall: #1 a2 - 10a = 2a - 36 #2 t(t - 5) = 5 (t - 5) #3. (x + 4)(x - 3) = 8 Thanks. Answered by Jack LeSage and Penny Nom.
	Factoring		1999-03-30
		From Maggie Stephens: I don't know anything about factoring would you plese help me. 3x4 - 48 54x6 + 16y3 125-8x3 12x2 - 36x + 27 9 - 81x2 a3 + b3c3 I would greatly appreciate any help you can give me thanks. Answered by Jack LeSage.
	Standard Form		1999-03-30
		From Pam: How do you put this equation into standard form? y=3.572x+5.409 Would you please put this equation in this form Ax+Dy+C=0 Answered by Penny Nom.
	A Frustum		1999-03-29
		From Monica Armour: What do you call a square pyramid that has had the top chopped off? Answered by Chris Fisher and Jack LeSage.
	Factoring polynomials		1999-03-29
		From Karen: I have been unable to factorise a polynomial equation and was wondering if you could please help. It is level (10-12) maths. The polynomial is x3 + x2 - 24x + 36 I have tried a few factorisation methods such as foctorisation by grouping but it won't work this polynomial. Please help. Answered by Jeff Walters and Jack LeSage.
	Resources for real-world math activities		1999-03-26
		From Kate O'Brien: Where is there a collection of math acitivities or projects to use in high school Algebra I, Algebra II, or Trigonometry that tie concepts to real-world careers? Answered by Jack LeSage.
	Cubic feet and gallons		1999-03-26
		From Karen Coheley: How many gallons in a cubic ft. ?? Answered by Harley Weston.
	Complex numbers/polar coordinates		1999-03-25
		From Kate Cegelis: What is the relationship between complex numbers and polar coordinates? Answered by Harley Weston.
	Prime dates		1999-03-25
		From Jessica Brown: I'm asking how do you figure out all the prime numbers in a year and, whats the average amount of prime numbers per week. Answered by Jack LeSage and Penny Nom.
	A word problem		1999-03-25
		From Anna Gariss: A second number is 4 less than a first number. The product of the second number and 3 more than the first number is 18. Find the pair of numbers. Answered by Jack LeSage and Penny Nom.
	Rhomboid		1999-03-25
		From Monica Armour: I need to see a net of a rhomboid. Where can I find one on the net? Is it like a square paramid with the top chopped off? Help! This has me stumped. Answered by Jack LeSage.
	Probability and Statistics		1999-03-25
		From Karrie Waller: Hi my name is Karrie and I am an elementary ed. student at Florida State University in Tallahassee, Florida. I am doing a report on how children learn probability and statistics. I am having trouble locating information that will tell me specifically how students learn. I am wondering if you can answer this question for me or direct me in the right direction. Answered by Jack LeSage.
	A field trip		1999-03-18
		From Jennifer Rudd: This word problem is driving me nuts! I could really use your help. Its a secondary level question. Here it is: A group of students planned to charter a bus for a school field trip. Each student was to share the $810 cost equally. However, 3 people were unable to go and this increased the share of each person by $3. How many went on the trip? Thanks! Answered by Jack LeSage and Penny Nom.
	Percentages		1999-03-16
		From Beth Barton: If I have two figures and want to know the difference between them, in Percentage, how do I proceed with a calculation? Example: 67,800 - 56,000 = 11,800 What percentage does this difference represent? Answered by Jack LeSage.
	0/11		1999-03-09
		From Jacob: What is the term applied to 0 divided by a number. In calculating slope problem my answer was 0 divided by 11. I don't know what to do with this answer or how to interpret it. Answered by Jack LeSage and Penny Nom.
	Factoring		1999-03-08
		From L. Sivad: Question: m2+6m+9-n2 Answered by Penny Nom.
	An airplane problem		1999-03-08
		From B.M.R.: A plane left New York and headed East to its destination 3600 miles away across the Atlantic. On the way back its speed was boosted by a 50 mph tail wind and it arrived an hour early. What was its normal speed? Answered by Jack LeSage.
	Metric Conversion		1999-03-07
		From TDestra: Please help to answer this question: Is a cubic centimeter equivalent to milligrams or milliliters, and how many? Also, is it a liquid measure? Answered by Penny Nom.
	Where three sequences meet.		1999-03-06
		From Ali: My name is Ali and I am in the 5th grade. I have a math question: What is the least positive integer meeting each of the following conditions: Dividing by 7 gives a remainder of 4 Dividing by 8 gives a remainder of 5 Dividing by 9 gives a remainder of 6 Help! Answered by Denis Hanson.
	Reversing the direction of an inequality.		1999-03-06
		From Mallory White: If the Problem was -4a plus -5 is less than or equal to 14, why would you change the sign to greater than or equal to? Answered by Jack LeSage and Harley Weston.
	Enlarging a Rink		1999-03-06
		From Jennifer Rudd: I've been having difficulty with this one question involving area. The level of the question is Grade 11/12. Here it is! A rink is 40 m long by 20 m wide. There are plans to enlarge it by 700m2 by adding a strip at one end and a strip of the same width along one side. Find the width of the strip. (Let the width of the strip by x meters.) Answered by Jack LeSage.
	The square root of two is never supposed to end		1999-03-06
		From a wondering student: i am algebra II and am in the 9th grade. today we were talking about rational and irrational numbers. When we were talking about square roots my friend and i were talking and we thought of something. if you have a square with sides of length one then the diagonal of the square is the square root of 2. Now the square root of two is never supposed to end. But the diagonal of the square ends so therefore doesn't the square root of 2 end. our math teacher did not really answer our question because it was not in the lesson plan and not to many people would see where we were coming from. the answer is really bugging me and i would like to have your input. Answered by Jack LeSage and Penny Nom.
	Quotients		1999-02-25
		From Brian Healey: what is a quotient? what is a divisor? what is a divident? Answered by Jack LeSage.
	Converting mm's to inches		1999-02-22
		From Paul White: It has been a long time since high school and I do not remember how to convert mm to inches. Could you please tell me what this would convert to in inches? 210 X 254 mm. Answered by Chris Fisher.
	Divisibility by 9		1999-02-21
		From Razzi: I've been having a hard time trying to solve the following problem and I was wondering if you could help me. For any positive integer a let S(a) be the sum of its digits. Prove that a is divisible by 9 if and only if there exist a positive integer b such that S(a)=S(b)=S(a+b). Answered by Chris Fisher and Harley Weston.
	Finding a rule for a sequence		1999-02-17
		From Lindsey Masters: I'm doing a maths investigation and i have a sequence which goes:- 13,16,25,32,45,56,73. Our teacher told us we have to find a rule by looking at the differences of the terms until we find a constant. The first differences are:- 3,9,7,13,11,17. The differences of these are:- ...... Please could you tell me how to work it out so that I could work out the rules of similar sequences. Answered by Penny Nom.
	A palindrome		1999-02-16
		From panajoti: Find the smallest number that must be added to 70808 so that the digits would read the same backward or forward. Answered by Penny Nom.
	Four Corners Maths Problem		1999-02-16
		From Helen Williams: I am currently a student teacher in the UK and I have to write a 1000 word report on the following maths problem which I am completely stuck on! PLease HELP!! Choose and 3 by 3 section of the hundred square. Add the total of the four corners. How many different groups of four numbers can you find that add up to that number? eg, 1 2 3 11 12 13 21 22 23 Total of 4 corners add up to 48. Adding 2, 13, 22, 11 also make 48 etc.. How many different groups of 4 numbers would add up to 48? How would these results compare with thoses obtained from a 3 by 3 square in which the numbers are consective? eg, 1 2 3 4 5 6 7 8 9 PLEASE HELP AS I AM COMPLETELY STUCK? WHY DO ALL THESE DIFFERENT WAYS ADD UP TO THE SAME NUMBER?? Answered by Harley Weston.
	Circumference and Area		1999-02-16
		From Natalie: finding the circumference of a circle? formula finding the area of a parallelogram? formula Answered by Penny Nom.
	The Board Problem		1999-02-15
		From Avery: Mr. Avery has 3-foot boards and 4-foot boards. If he puts the 3-foot boards in a line, they have the same length as the 4-foot boards put in a line. Altogether he has between 16 and 25 boards. How many 3-foot boards does he have? Answered by Jack LeSage and Penny Nom.
	Magic Squares		1999-02-11
		From Katie Powell: My name is Katie Powell. I'm in the 7th grade, taking Algebra. I live in Houston, Texas. My problem is this: "Use the numbers 1-9 to fill in the boxes so that you get the same sum when you add vertically, horizontally or diagonally." The boxes are formed like a tic-tac-toe -- with 9 boxes -- 3 rows and 3 columns. Can you help? Answered by Jack LeSage.
	Dig digs in the garden		1999-02-11
		From Katherine Shaw: A circular garden has an a radius of 8m. Dig, the dog, is tied up to a fence that runs round the outside of the garden. Dig was able to dig up all the garden, apart from an area of 64 square metres, which he couldn't reach. How long was his lead? Answered by Chris Fisher and Harley Weston.
	Satellite dishes		1999-02-10
		From Katherine Shaw: I have read your information on 'Why are satellite dishes parabolic", and I know the reciever should be placed at the focus of the parabola. Could you test this with lights beams and a parabolic mirror, or would light beams behave differently. Thanks. Answered by Jack LeSage and Harley Weston.
	Non-Euclidean Geometry		1999-02-10
		From Robert Smith: Is non-euclidean geometry necessary for the college bound student? I have students that are inerested in teaching math one day. My school is restricted to Euclidean Geometry. Answered by Walter Whiteley and Jack LeSage.
	Word problems		1999-02-09
		From Brian Rodriquez: Please answer these problems with a formula. Also explain in English step by step how these problems should be solved. I know the answer I just don't know how the answer was achieved Thank you very much for trying to help A ski lift carries a skier up a slope at the rate of 120 feet per minute and he returns from the top to the bottom on a path parallel to the lift at an average rate of 2640 feet per minute. How long is the lift if the round trip traveling time is 20 minutes? An airplane on a search mission flies due east from an airport, turns and flies due west back to the airport. The plane cruises at 200 miles per hour when flying east, and 250 miles per hour when flying west. What is the farthest point from the airport the plane can reach if it can remain in the air for 9 hours? Answered by Jack LeSage and Penny Nom.
	Grade 4 curriculum		1999-02-09
		From John: My daughter is in grade 4 and her math teacher has asked her to write out the number 1 to 10,000. She is currently at 4567 and is sick of it. When I complained that this was not a usefull exercise she said that the Ministry of Education curriculum requires this and gave a photocopy of the page. It states: "read and write whole number to 10,000 in standard, expanded, and written forms (eg., 9367=9000+300+60+7 = nine thousand three hundred sixty-seven). Has the teacher interpreted this the wrong way? Thanks John PS. Do you have a web address for Ontario Math and Science Teachers organization? Answered by Jack LeSage.
	Primary Mathematics		1999-02-08
		From Syairul: Mr Wu earned $2365 in January. He earned $375 more in February than in January. If he spend $4250 in the two months and saved the rest, how much did he save? Answered by Jack LeSage.
	John Napier and e		1999-02-06
		From Shimin: I would like to ask about the exact definition of e, its history (like how John Napier came about discovering it) and its applications in problems and real life situations. Thank you! Answered by Chris Fisher.
	Dividing Decimals		1999-02-06
		From Melanie Campbell: i ugently need to know how to divide a decimal by a decimal eg:6.0 divided by 2.4 i need to show all working on a basic skills exam please help!!!! mel Answered by Jack LeSage.
	Lunes		1999-02-04
		From Kai G. Gauer: A prof once told me that a certain type of lune is quadrable given that the diameter is an integer. She used the construction of a right isosceles triangle within a semicircle and later constructed another semicircle on the base of the first semicircle and used area subtraction to show equality to a smaller triangle with quadrable area. What happens when the original inscribed triangle is no longer isosceles? She mentioned something about other lunes also being quadrable; but not all. What are the dimensions of other such lunes? Note: I'm not certain if I still have my hercules account; please simply post on Q&Q. Thanks! Answered by Chris Fisher.
	Modular Arithmetic		1999-02-04
		From Leslie Kupper: I am trying to do a project on modular arithmetic. I was wondering if there were any websites that include a sample lesson plan on modular arithmetic for any grade level. Let me know where and how to find them. Thanks. Answered by Harley Weston.
	Money and Counting		1999-02-03
		From Deborah Goodman: I am looking for ways to tutor my daughter in money counting and handwriting skills. Answered by Jack LeSage.
	Cannonballs		1999-01-27
		From Roger King: How many cannonballs can be stacked in a triangular pyramid? Answered by Penny Nom.
	Simplifying Radicals		1999-01-26
		From Mary: I would like to know how to simplify this question: 4 __________________ squareroot7 + squareroot3 I know the answer is (sqrt7 - sqrt3) but i would really love to know how to get that answer!! Thanks. Answered by Jack LeSage and Penny Nom.
	Simplifying Radicals		1999-01-25
		From Randy: Find the perimeter of a rectangle in simplified radical form L=root80 W=root45. I would appreciate a detailed explination of the process for solving. Answered by Jack LeSage and Penny Nom.
	The Quadratic Formula		1999-01-22
		From Eric Morgan: Hi my name is Eric Morgan and I m in 8th Grade honors math (middle) and I'd like to know how to prove the quadratic formula -b±sqrt of b(a)(c)over 2(a) Answered by Penny Nom.
	Angles in Polygons		1999-01-21
		From Jen: How do u find the interior angles of a pentagon when you are given 4 of the angles and you need to find the fifth? If you are given the measure of each exterior angle of a regular polygon, how do you figure out how many sides the polygon has? i need all information on polygons and how to find their angles!!! Answered by Jack LeSage.
	Root 17 is Irrational		1999-01-21
		From John Murdock: If you could help me out with this I would appreciate it. Prove that the square root of 17 is irrational. Answered by Harley Weston.
	Math and Writing		1999-01-21
		From Nancy Waite: This may not be an inquiry for this particular service, but we are searching for teacher resources incorporating writing into mathematics. With the new state math frameworks, our district is emphasizing using the writing process to develop thinking skills in math. We are gathering available resources in this area so we can begin formulating a plan to incorporate writing skills into the mathematics curriculum. Answered by Walter Whiteley and Rick Seaman.
	Math Olympics		1999-01-19
		From Kim Brandson: I am trying to put on a Math Olympics for K-5 students in my district. Any ideas? Resources? Suggestions? Answered by Jack LeSage.
	Fitting a Curve		1999-01-19
		From Kirk: Hello my name is Kirk from Scarborough, Ontario. I have been out of a formal education system for thirty years. I program microcontrollers in my spare time. I have built a temperature sensing device ready to go but, thermistors are very non-linear. I do know that there is a way to calculate the input condition of the thermistor and display the correct temperature in degrees C. I am sending a file to show my progression so far. Answered by Harley Weston.
	Graphing the Derivative		1999-01-18
		From Milena Ghebre: This question has been nagging me for sometime now. Is there a way of finding out the derivative of a function, just by looking at the graph of it? Answered by Walter Whiteley.
	Calculus		1999-01-16
		From Kaylea Rankin: Differentiate the following. y = 1 /(2+3/x) Answered by Jack LeSage and Penny Nom.
	Linear Equations		1999-01-16
		From Casie Tomney: My dad and I have been trying to figure, how to solve for x on any of these problems my teacher gives us. The problem is: 2h/3 + 1/2 = 5h/6 - 3/4 Thanks!!!!!!!! Answered by Jack LeSage.
	Turning Fractions into Decimals		1999-01-16
		From Lynn: How do you do it step by step Answered by Jack LeSage.
	Levers		1999-01-13
		From Lane Campbell: 1. Solve for x or y. (a) <-----4m------><------4m-----><---------xm ---------> _____________________________________________________ ^ ^ ^ ^ 25N 5N ^ 15N Answered by Jack LeSage.
	Patterns		1999-01-07
		From Melis Kalay: I'm confused about questions like these: 1. 2by2by2 cube: If this cube was painted blue on the outside, how many cubes would have 3 blue faces 2 blue faces 1 blue face 0 blue faces Answered by Jack LeSage and Penny Nom.
	Absolute value of i		1999-01-06
		From Wayne Bagley: I would like to know what is the absolute value of i. I need an answer suitable for the secondary level. Answered by Harley Weston.
	Place Value		1999-01-05
		From Reg: I work in a Section 27 classroom with various grades. I am looking for assistance on how to deliver a lesson on place value:decimal numbers keeping in mind that they need to see it (visual) to comprehend. I am looking for grade 4-6 level. Answered by Jack LeSage.
	A handshake problem		1999-01-05
		From Nick Lam: There are 40 people at a party. 1 host couple, a mom and her daughter. There are 19 other guest couples, composed of moms and their daughters. The Host couple shakes hands with everyone except each other. Each guest mom shakes hands with everyone but their own daughter. Each guest daughter shakes hands with everyone except their own mom. A hand shake between two people is considered to be one handshake. HOW MANY HANDSHAKES ARE THERE? Answered by Penny Nom.
	Pythagorean theorem research project		1998-12-31
		From Mohammed Hasan: Hi my name is Mohammed Hasan. I am a math honors student in 8th grade. I have to do a research project in math. The only problem is that I have to do the research project at a 10th grade level. I am having trouble raising the project at a tenth grade level. Would you please kindly take your time to give me some tips and web sites that will help me raise the Pythagorean theorem to a 10th grade level. Answered by Jack LeSage and Walter Whiteley.
	Geometry patterns lesson plans		1998-12-31
		From Vicki: hi,,, my name is Vicki and I am a new 5th grade teacher.... Anyway, I'm supposed to come up with a lesson plan to Explore patterns that result from cominations of "reflections, rotations, and translations of geometric figures. The plan is to include: writing/metacognition, assessment strategies, interdisciplanary connections, supplemental materials, or textbook, and Bloom's taxonomy level. Any help you could give would be greatly appreciated. Thanks Answered by Jack LeSage.
	The area of a triangle		1998-12-26
		From Elysia: How do you figure the square inches of a triangle? Answered by Harley Weston.
	Complex numbers and the quadratic formula		1998-12-25
		From Richard Peter: My age is 16, and my name is Richard. My question relates to the topic complex numbers & the quadratic formula. I would like to know how to solve quadratic equations in which the discriminant is less than 0 (i.e. we get two complex solutions to the quadratic) 3x2+2x+5 = 0 and how mathematicians like euler contributed to this field. If it would be possible I would also like to know how this type of quadratic equations can be graphed? Answered by Harley Weston.
	Complex Numbers		1998-12-23
		From Wayne Bagley: I would like to know what is the square root of i , and i squared? I am looking for a response appropriate for secondary level students. Answered by Harley Weston.
	Some Word Problems		1998-12-17
		From Jennifer Rudd: To Whom It May Concern, I'm having some difficulty with these word problems. Maybe you could help. Thanks. A matte of uniform width is placed around a painting so that the area of the matted surface is twice the area of the painting. If the outside dimensions of the matte are 40cm and 60cm, find the width of the matte. The Joneses start out A 1520km car trip to Walker Park. On the first day they cover 960km. On the second day they complete the trip, but a rainstorm causes them reduce their average speed by 10km/h.If the 2-day trip took a total of 20 h, what was the average speed on each day? Granny stood up at her grandson's wedding reception and announced " My age now is a perfect square and it is equal to the difference between the square of my grandson's father's age and the square of his mother's age. Come to think of it the difference my age and the square of my grandson's age is seven times the age of his mother, my daughter in law." The grandson's wife remarked to her new husband," That means the difference between the squares of our ages is three times the age of your father!" How old was the bride? The volume of a retangular box 4cm high is 144 cubic cm. If the perimeter of the base is 24cm, find the dimensions of the box. P.S. the first two questions are the most important ones that need to be solved. Thanks for your help!! Answered by Jack LeSage and Penny Nom.
	Indeterminate forms		1998-12-11
		From R. Dixon: What is the correct evaluation of infinity/0 ? I've checked three different math sites. One says definitively, that infinity/0 is "not" possible. Another states that infinity/0 is one of the indeterminate forms having a large range of different values. The last reasons that infinity/0 "is" equal to infinity. Answered by Walter Whiteley and Harley Weston.
	Volume in gallons		1998-12-09
		From Hill Hermit: Please tell me the formula for computing the volume, in gallons, of a cylinder. Thanks from a parent. American gallons, please. Answered by Harley Weston.
	6.99999... = ?		1998-12-05
		From Tom: I have had a rather heated arguement with my students. Please settle this for me. Solve <,>, = 6.99999... __ 7 Thank you. Answered by Penny Nom.
	Intersection of Planes		1998-12-03
		From Lindsay Fear: My name is Lindsay Fear. I am an OAC student (which is the Ontario equivalent to Grade 12 in most other states and provinces). I am in an Algebra and Geometry course and am currently studying a unit on equations of planes. Our teacher has given us this question that my friend and I have attempted several times, but we are still unable to solve it. My teacher has also suggested using the internet as a resource. The question is: Prove that a necessary condition that the three planes -x + ay + bz = 0 ax - y + cz = 0 bx + cy - z = 0 have a line in common is that a^2 + b^2 + c^2 + 2abc = 1 Answered by Walter Whiteley.
	-(4)^0 = ?		1998-12-02
		From Derek Yau: I would like to know why any number to the exponent 0 equals to 1 also, I would like you to please answer this question: -(4)^0 = ? I know the answer is 1 but I am confused as to if it is a negative one or a positive one. Answered by Jack LeSage and Penny Nom.
	Platonic Solids Surface Area		1998-12-02
		From Rachel Bidwell: How do you find the surface area of the 5 platonic solids, when they each have a volume of one cubic inch Answered by Harley Weston.
	Percentage markup		1998-11-28
		From John Coffey: My 11th grade daughter asked me how to calculate retail mark up percentages, I would appreciate any help with this question. Answered by Penny Nom.
	Pick any odd number, square it, and then divide it by 8		1998-11-27
		From Brenda Meagher: Pick any odd number, square it, and then divide it by 8. No matter what odd number is chosen and squared and divided by 8, the remainder is one. Could you please explain this to me or is there a pattern that I am not aware Answered by Harley Weston.
	Matricies		1998-11-26
		From Stephanie Webster: If a matrix for a rectangle looks this way: AACC BDDB What does the matrix for a square look like? Answered by Penny Nom.
	Duplation method of multiplication		1998-11-26
		From Sara Whitford: I am wondering why 16 and multiples of 16 do not work in the ancient duplation method of multiplication used by the Egyptians. I discovered the method in the Journeys math text gr 7 level. Just curious. Am I doing something wrong?? Answered by Jack LeSage and Harley Weston.
	Three keys		1998-11-26
		From Karen Chan: A man has a bunch of three keys, only one of which fits the lock of his front door. When he comes home in the dark he tries the keys at random until he finds the one fits. Find the probability that in a week of five nights, he tries the right key first on at least one night. Answered by Penny Nom.
	Algebra		1998-11-25
		From Casey: yeah my son brought home a math worksheet and he was wondering and me too if u could help him and me out . he has problems like this 4n+9=7n+2= ??? and he has to show work so if u could help us out that would be great Answered by Jack LeSage.
	A number between		1998-11-25
		From Jimmy Nikola: A number is less than 3,425 + 8,630 and greater than 7,614 + 4,429. What could the number be? This question is on page 93, question number 23. in Silver Burdett Ginn Math book, which is a 3rd grade math book. Answered by Jack LeSage.
	The bricklayers formula		1998-11-24
		From Rachel Kaplan: I have to do a report on the bricklayers formula N = 7LH. Can you give me any information on this. Answered by Harley Weston.
	Intersection of planes		1998-11-22
		From Dave Rasmussen: I am a teacher of secondary mathematics with a question about the uses of Three Dimensional Co-ordinate Geometry. I have been teaching my students to write equations of planes and lines, - to find the intersection of these and the distance between them. What I am having difficulty finding are good applications of these techniques to "real world" situations. Can anybody help me? Answered by Walter Whiteley and Harley Weston.
	Fraction division		1998-11-18
		From Brett Darrough: I am needing specific examples that illustrate division of fractions with In-depth understanding. I am enrolled in a CGI (cognitivly guided instruction) course which is trying to develop a method of teaching fraction division with understanding. Most people invert and multiply to obtain a correct answer. Why? I would like help in understanding this method that includes pictures and algorithms that illustrate reasoning and depend on understanding. Answered by Jack LeSage and Harley Weston.
	A tetrahedron inscribed in a cube		1998-11-18
		From Jane: In analyzing a cube, I would like to find a tetrahedron inscribed in the cube which has none of its faces in the planes of the faces of the cube. I would like to see this tetrahedron outlined in the cube. My name is Jane and my e-mail address is BARSOIAN. I am an elementary education student. Answered by Walter Whiteley.
	Three dice		1998-11-17
		From Ryan Allinson: Rolling three regular dice how many different ways could a sum of 10 be rolled? Hope you can help. Can you please show me how this is done? Answered by Penny Nom.
	Linear systems of equations		1998-11-16
		From Crystal Girvan: My name is Crystal Girvan.Im in grade 11. I have a question.We are solving linear systems of equations: comparison method. My questions is. it says a)use the method of comparison to solve this system a=b-1, 3a+ b=3 b) verify your solutin in a I dont understand it. please help Answered by Jack LeSage.
	Terminating decimals		1998-11-16
		From Debra Karr: A college student studying elementary education asked me a question that I could not think of the correct answer. How can you look at a fraction and tell if is a terminating or non terminating decimal? Answered by Jack LeSage and Penny Nom.
	A trig limit		1998-11-14
		From Amy Atwell: what is the limit of of tanx / x + sin x as x approaches 0 Answered by Harley Weston.
	Golf Problem - The Sequel		1998-11-13
		From Bob: Sixteen golfers, seven rounds. What are optimum combinations for each golfer to play with as many different golfers as possible? Many thanks, Bob Payson Answered by Denis Hanson.
	What's the next term?		1998-11-12
		From Ilia: What the formula and explonation for formula for next patterns: 1) 1, 4, 10, 20, 35, 56, 84,... 2) 0, 6, 30, 90, 210, 420,... Thanks! Answered by Penny Nom.
	Arithmetic Progressions		1998-11-12
		From Gerry Boser: It has been years since I was in school and I can't remember if there is a formula for the following problem: If you deposit $1.00 on the first day of the month, $2.00 on the second day, $3.00 on the third day . . $31.00 on the last day of the month, how much do you have in the bank? Now will this formula also work if it was, $0.25 (then day two you would deposit 2x $0.25 or $0.50, day three you would deposit 3x $0.25, $0.75. . . ). Will it work with any denomination?? Thank you for your time. I promise I'll write this one down for future reference. . . Answered by Penny Nom.
	Two sides and a bisectrix.		1998-11-11
		From Victor Grinshtein: I am looking for someone who can tell me how to construct a triangle by 2 sides and a bisectrix using a compass and a ruler. Answered by Chris Fisher.
	Centimetres		1998-11-11
		From Vicky Caldwell: I work in Carpet Manufacturing and I need to know how to figure the calculation for a roll of carpet in centimeters. For example: a 12 x 100 roll of carpet equals 133.34 square yards, which is 100 linear ft. and 1,200 square foot. Can you please tell me how I would figure to get CENTIMETERS??????? Answered by Jack LeSage.
	Touch Math		1998-11-09
		From Melinda Robinson: I am a contracted district substitute teacher for grades K-8. My teacher education courses did not include anything about "touch math," a system used by some of the teachers for whom I sub. Is there a book available that I could acquire to teach this system to myself, and have as a reference? Answered by Harley Weston.
	Kumon		1998-11-09
		From Kathy Steele: Perhaps I am not spelling this correctly,since there is nothing to be found on Kumin Math, but my search for info on this topic led to this site. My understanding is that it is a program of repeated drills. Do you have any additional information? I know that this will come up during Parent conferences since some of my Jr. High students are talking about it. Answered by Jack LeSage and Harley Weston.
	Triangular Numbers		1998-10-30
		From Matt: i would like to know about triangular numbers and it history i would also like to know about the history of prime numbers thank you Answered by Chris Fisher.
	Divisibility by 11		1998-10-28
		From Pat Duggleby: I am an upgrading instructor at a drop-in program in Regina. One of my students is taking General Math 30 through correspondence, and we have run into some confusing instructions. The section is about divisibility rules, and we did just fine up until the rule for Divisibility by 11. The statement is as follows: If the difference between the sum of the odd-numbered digits and the sum of the even-numbered digits, counted from right to left, is divisible by 11, then the number is divisible by 11. . . . Answered by Penny Nom.
	A Puzzle		1998-10-27
		From Bruce Bragnu: We are trying to solve what SHOULD BE a simple 7th grade problem and have run into a wall. It is: ABCD ABCD ABCD ABCD ------- EBEA It is an addition problem. Each particular letter represents the same digit. We are looking for what number "B" represents. We have tried a multitude of solutions and have come up empty. Answered by Penny Nom.
	Fractions		1998-10-27
		From Jessica Braimoh: I have a problem that I just can't figure out!! Put into a fraction a) -1.157... b) 0.046... c) 0.032... d) -0.3234... Please show how you got the answer and how you came to it(step by step) Thanks Jessica Braimoh grade 9 Ontario Answered by Harley Weston.
	A Six Digit Number		1998-10-27
		From Craig Bedard: If a certain six-digit number is split into two parts, one constituting the first three digits and the other the last three digits, and the two parts are added and the resultiong sum squared, it is found that the product is the original six digit number. What is the original six-digit number? At first it seemed liked an impossible question, until it hit me...how long will it take you? Answered by Jason Stein and Dan Usselman.
	A Number Trick		1998-10-26
		From Brenda Meagher: I'm a 37 year old mother and i have returned to school for personal reasons. I was faced with this question. Choose any number less than 10, multiply it by 8547, then take your answer and multiply it by 13. I chose the number 8. 8547 x 8 -------- 68376 and 68376 x 13 --------- 205128 68376 --------- 888888 Any number chosen from 1 to 9 will result in the same form of answer.If the number two is used you will end up with 222,222.etc So my question is, is there another number that will results in the answers. Answered by Harley Weston.
	Logs		1998-10-21
		From Benny: What does log means? How come we have to use log Answered by Chris Fisher.
	Complementary and Supplementary Angles		1998-10-21
		From Christina Saunders: I am in 9th grade and my math teacher wanted us to find out why complimentary angles are called complimentary and why supplimentary angles are called supplimentary. I have looked everywhere and asked numerous people, but I have yet to find an answer. My math teacher said it had something to do with trigonometry. Do you have an answer for me? Answered by Chris Fisher and Penny Nom.
	The Left Side of a Parabola.		1998-10-20
		From Shay: Find the parametrized equation for the left half of the parabola with the equation: Y=x^2-4x+3 Answered by Chris Fisher.
	Adding Fractions		1998-10-15
		From Lindsay: please help me!!!! Answered by Harley Weston.
	Problem Solving		1998-10-15
		From Pamela Fisher: Can you give me a comprehensive list of problem solving stategies. I teach grade one in a K to 8 school and we are working on improving problem solving at all grade levels. I have heard that there is a list of various strategies that we could adapt to different grade levels. Any help you give me would be appreciated. Thank you. Pamela Fisher Answered by Walter Whiteley.
	A Linear System		1998-10-08
		From Jason Bussey: The linear systems with the following pattern all have the same solution. Is their some kind of reasoning as to why this is so? 2x+3y=4 3x+4y=5 4x+5y=6 5x+6y=7 The solution is always x=-1, y=2 Thank you Jason Answered by Penny Nom.
	Operations Research		1998-10-08
		From Lisa Barrett: What is the history of operations research and the study of linear programming? Answered by Judi McDonald.
	Fractions		1998-10-07
		From Nikki Lakevold: -5 over 9 minus -2 over 3 plus -7 over 6 = ??? This is a fraction question and I really don't know why the back of my textbook says -19 over 18 when I got -23 over 18,, am I wrong??? Answered by Harley Weston.
	Composite Numbers		1998-10-07
		From Greg Murphy: What type of composite number has an odd number of factors? Answered by Harley Weston.
	Scientific Notation		1998-10-07
		From R. Pierce: Help! How do you express the following numbers in scientific(exponential)notation:0.00036 and 2998000000. I understand how to solve them if it was an equation, but this is confusing me. Please help me answer my questions. Thank you. Answered by Harley Weston.
	A Kite		1998-10-07
		From Paul Scott: What is the mathematical term for the kite shape? Answered by Walter Whiteley.
	Number Systems		1998-10-07
		From Frans: What other number system are there besides the real number system and the complex number system? Interested adult thanks Answered by Penny Nom.
	A Sum or Product of Fractions		1998-10-06
		From Emily Robb: Find a pair of fractions that when they are multiplyed and added the sum /product is the same Answered by Penny Nom.
	Points on a Graph		1998-10-03
		From Nouver Cheung: If the point P(-3,2) is on the graph of y=f(2x-1), what point must be on y=f(x)-3? Answered by Harley Weston.
	Adding Fractions		1998-10-03
		From Pam Bailey: Can you help me simplfy this? (1/2a + 1/3b) - (1/4a - 1/5b) + (1/6a - 1/7) thanx Answered by Harley Weston.
	Students and Lockers		1998-10-02
		From Mike: There is a row of 1000 lockers. There is a line of 1000 students. Student number 1 starts at the first locker and opens all 1000. Student number 2 starts at the second locker and closes every other one. Student number 3 starts at the third locker and goes to every third one, closing the open ones and opening the closed ones. Student number 4 does the same with every fourth locker and so on down the line... After all 1000 students have gone how many lockers are open and which ones are they? Please help! There is proboly a simple solution but we couldnt figure it out for the life of us. Please let us know how you solve it. Answered by Patrick Maidorn and Penny Nom.
	French Francs		1998-10-01
		From Richie Franklin: 1.what did one dollar equal in France francs ten years ago, twenty years ago, and fifty years ago? Answered by Chris Fisher.
	Dividing a Class		1998-10-01
		From Tom Barker: My eighth grade niece called with the following homework problem: A teacher wanted to divide her class into equally numbered groups. She tried to divide the class into groups of two, but was one student short. She tried to divide the class into groups of five, but was one student short. She tried to divide the class into groups of seven and was successful. What is the least number of students that were in her class? I know the answer is 49, but don't know how to prove it. I must be getting old if I can't solve eighth grade math problems. Your assistance would be appreciated. Answered by Penny Nom.
	Repeating Decimals		1998-10-01
		From Chris Norton: Could you PLEASE give the formula to find out the number of digits in a repeating decimal before it repeats. I have been trying to get it for weeks from Math sites on the Internet. Can you please, please help me ? Chris Norton Answered by Chris Fisher and Penny Nom.
	Two Chords		1998-09-29
		From Jennifer Cane: Question: two parallel chords of a circle, AB and CD, have lengths of 10 cm and 17 cm respectively. The diameter of the circle is 21 cm. Find the shortest distance between the chords. Answered by Harley Weston.
	An Implication		1998-09-27
		From Danielle Evans: i am in my second year of math for the liberal arts and a problem has be terribly confused.. can you answer this [(p --> q) ^ (q --> p)] --> (p <--> q) is this an implication?? i would love to hear your answer thank you... danielle evans Answered by Chris Fisher.
	A Horizontal Line		1998-09-23
		From Tess Warer: Find the equations of a line through (-1,-5) and parallel to the X-axis. Answered by Harley Weston.
	Nickles on the Highway		1998-09-22
		From Ronnie Mac Donald: How many nickels would it take to cover 226km of highway,each nickel is 2cm in diameter? Answered by Penny Nom.
	A Hexagon		1998-09-22
		From Lee Curtis: Could someone calculate this for me? If a hexagon is 38 feet 8 inches across, how wide would each of the six sides be? Thank you, Lee Curtis Answered by Chris Fisher and Harley Weston.
	Help the Helper		1998-09-20
		From John Derr: I am TRYING to help my niece with her Community College Teacher's math course! I have a BS and an Engineer yet stumble on what her book is asking: Fill in the blanks to continue this sequence of equations: 1 = 0+1 1+3+1 = 1+4 1+3+5+3+1 = 4+9 _______________ = ____ _______________ = ____ What expression, suggested by part (1.), should be placed in the blank to complete this equation? 1 + 3 + 5.........+ (2n-3) + (2n-1)+ (2n-3)+...+5 + 3+ 1 = _________  Answered by Penny Nom.
	Five Factors		1998-09-19
		From Derek Yau: To whom it may concern, I have difficulty in getting the solution to the following question: Find 5 numbers that have exactly 5 factors. I got 16, 81 but couldn't find the rest. I believe that in order to have 5 factors, it has to be a square number. Isn't it true? I guess there may be a pattern to this. Thanks for your help. Derek Yau. Answered by Penny Nom.
	Rational and Irrational Numbers		1998-09-19
		From Ri: I am trying to explain rational & irrational numbers to my niece who is grade 7 and am having difficulties. Could you please explain the difference between rational & irrational numbers. Thank you Ri Answered by Penny Nom.
	Simplifying Roots		1998-09-18
		From Lauren Lattimer: 1. 2root27 divided by root 12 2. 3 root 48-root 75 Answered by Penny Nom.
	Probability		1998-09-17
		From Chris: Six marbles are placed in one of three boxes. What is the probability that each box contains two marbles? What is the formula used? Answered by Penny Nom and Chris Fisher.
	Unit Fractions		1998-09-16
		From Murray MacNeil: Sir, my nephew is having trouble with math,he is in grade 10. this is his question. Find seven unit fractions whose whole sum is one. thank you murray macneil Answered by Penny Nom.
	Random		1998-09-15
		From Hugh Ballantyne: I am an occasional teacher. Here is my question: Does the word "random" have a technical meaning in mathematics? Answered by Harley Weston.
	Radicals		1998-09-15
		From Lana Sabo: Question: fifteen times the square root of twenty, divided by the square root of 2. nine subtract the square root of forty-five, divided by 3. the square root of 18 plus the square root of 12, divided by the square root of 3. Answered by Harley Weston.
	A Pattern		1998-09-14
		From Krystin: Question: 1=1x1 1+2+1=2x2 1+2+3+2+1=3x3 draw a series of diagrams to illustrate the above pattern Answered by Penny Nom.
	Human Calculator		1998-09-14
		From Pam Sloan: I recently saw a special on NBC Dateline about a man known as the human calculator. They called him Mr. Math. I want to know more about his books, seminars, and activities. Also, what is his real name? Answered by Patrick Maidorn.
	(1+z+z^2)^2		1998-09-10
		From A.R.: These questions deal with factoring. (1+z+z^2)^2 and (p^2-pq+q^2)^2 I partially understand the second line which would be 1+z^2+z^4+2z+2z^2+2z^3 but I don't understand where the 2 comes from in the second half of that line. p.s.(^2 means squared or cubed etc.) Please help me out A.S.A.P.! I have a quiz on this tomorrow! Thank-you, A.R. Answered by Harley Weston.
	Triminoes		1998-09-09
		From Roxanne Hale: I am doing an investigation about a game called triminoes (like dominoes). The game is played using triangular pieces of card. Each card has 3 numbers on it. I have to investigate the relationship between the number of trimino cards in a set and the largest number on the cards. I found; largest no. used 0 1 2 3 4 no. of trimino cards 1 4 10 20 35 I was ginen the formula for this which is: UN= UN - 1 + 1/2 (n + 1 ) (n+2) UN=no. of trimino cards n= largest no. I don't know how to get to this equation I think it has something to do with triangle numbers! Answered by Penny Nom.
	Cutting a Pizza		1998-09-09
		From Woody: what is the greatest number of pieces of pizza you can form if you use five straight cuts to cut the pizza? answer given is 16. please draw a diagram of the answer. thanks, woody Answered by Penny Nom.
	3 to the power of 1994		1998-09-05
		From Kim Tangney: What are the last two digits of: 3 to the power of 1994 7 to the power of 1994 3 to the power of 1994 + 7 to the power of 1994 7 to the power of 1994 - 3 to the power of 1994 Answered by Penny Nom.
	A divisor.		1998-09-05
		From Kim Tangney: When 391 758 and 394 915 are divided by a certain three digit numbers, the three digit remainder is the same in each case. Find the divisor. Answered by Penny Nom.
	Rational Numbers		1998-09-05
		From Kristin Mckenzie: Iam a secondary student with a math question I don't know how to do. This is the question: Explain whether each decimal number represents a rational number. (a) 0.16 (b) 0.12 (c) -3.125 (d) -0.27 (e) -0,212 112 111 2 .... (f) 0. 457 92 If it wouldn't be a problem i would really appreciate it if you sent back the instructions on how to do the question. My name is Kristin Mckenzie and my return e-mail is lexus1999@hotmail.com Thank-you for you time Answered by Jack LeSage and Harley Weston.
	Volumes		1998-08-29
		From Lorraine Wall: Consider the region in the first quadrant bounded by the x and y axes, the vertical line x=3 and the curve y = 1 / (x squared + 3). Determine the volume of the solid by rotating this region about the x-axis. Now that is the first part. I then have to find the coordinates of the centroid of the solid by rotating this region about the x-axis. Thanks. Lorraine Answered by Harley Weston.
	The area and the circumference of a circle.		1998-08-27
		From Jason Wright: I was looking at the relationship of the area of a circle and the circumference when I realized that 2*pi*r is the derivative of pi*r^2. I was wondering if there is any connective deep dark meaning as to why this appears to be related. Thanks for any help you can give me! Answered by Walter Whiteley.
	Golf problem		1998-08-25
		From Bob: Twelve golfers plan to play seven rounds of golf. Each would like to play as many rounds with different golfers as possible. What are the optimum combinations to accomplish that goal? Answered by Denis Hanson.
	Frieze Patterns		1998-08-19
		From Brian Bairstow: I am doing a research project on frieze patterns (also called band patterns or border patterns). I know that there are exactly seven different types of frieze patterns, but I have been unable to find a proof for this. If you could tell me this proof, or tell me some internet sites on which I can find material on this, I would be very grateful. Answered by Chris Fisher.
	Concurrent Lines in a Triangle		1998-08-10
		From Chris Woolf: The question is Name four types of concurrent lines, rays, or segments that are associated with triangles. Answered by Chris Fisher.
	Two Problems		1998-07-28
		From James Pulver: How do you solve these problem? If log abc=16 and log ac=12 , find b. (The logs are log base 10.) and If a and b are real numbers, i^2 = -1 and (a+b)+5i=9+ai what is the value of b? Answered by Jack LeSage.
	Area and Volume		1998-07-28
		From James Pulver: I am going into 12th grade and am practicing for the SAT II. I have come across a problem that I cannot solve. It states that the front, side , and bottom faces of a retangular solid have areas of 24 square centimeters, 8 square centimeters, and 3 square centimeters, respectively. What is the volume of the solid. I need to know how to solve similar problems so is there a formula to go from area to volume? Answered by Jack LeSage.
	Parabolas		1998-07-24
		From Danica: how do you find the focus, vertex, and directrix of 4x-y^2-2y-33=0 Answered by Penny Nom.
	Volumes of Revolution		1998-07-24
		From Lorraine Wall: I'm on the section fpr The Computation of Volumes of Solids of Revolution and the following question is giving me problems: -Consider the region in the first quadrant bounded by the x-and y-axes, the vertical line x=3, and the curve y=1/(xsquared + 3) I can determine the volume of the solid by rotating the region about the y-axis using the shell method but I can't seem to be able to get started with the volume when rotated about the x-axis. Answered by Harley Weston.
	Snake Eyes		1998-07-20
		Would you please advise me what the probability is of rolling snake eyes on a pair of dice is? My recollection is 1 out of 6 multiplied by 1 out of 6 = 1 out of 36 is this correct? Answered by Jack LeSage and Penny Nom.
	Solving Quadratics		1998-07-16
		From Fred Goodrich: I need a step by step lesson on solving quadratic equations. Thank you, Answered by Penny Nom.
	Calculus problems		1998-07-13
		From Lorraine: I'm stuck again. Can you help? This involves integration using the method of partial fractions the integral of: 7x(to the 5th) - 2x(cubed) + 3 dx -------------------------------------- x(to the fourth) - 81 Do I have to do long division to reduce the numerator to the fourth power? the integral of: 4- 16x +21x(squared) + 6x(cubed) - 3x(fourth) dx ---------------------------------------------------- x(cubed)(x - 2)(squared) Lorraine Answered by Harley Weston.
	Percentages		1998-07-10
		From Adam: Hi, I would like to know the basics of percentages. It is all rather confusing to me.I have excelled in math but want to be ready next year for more advanced math. What is Percentages? Answered by Penny Nom.
	Social Security Numbers		1998-07-07
		From Valerie Lucas: How many social security numbers are possible? the answer is 10^9 why isn't the answer 9^9? Answered by Harley Weston.
	A Calculus Problem		1998-06-28
		From Lorraine: I'm a post-secondary student taking calculus by correspondence. I'm stuck on the following question (and similar ones) Can you help? Evaluate the following indefinite integral: d(theta) ---------- 1 + sin (theta) (It says to multiply both numerator and denominator by: 1 - sin(theta) Thanks Lorraine Answered by Harley Weston.
	15 to the zero		1998-06-24
		From Mike Husken: My daughter has the problem: 15 with an exponent of zero=1. Could you help explain why? I would appreciate an answer soon as she has class tomorrow. thanks, Answered by Penny Nom and Patrick Maidorn.
	Difference of squares		1998-06-23
		From Kristen Smelsky: Solve the following using a difference of squares: 4x(squared) minus 4xy plus y(squared) minus m(squared) plus 2m minus 1 Answered by Penny Nom.
	The Birthday Problem		1998-06-12
		From Josh Skolnick: if you are at a party what is the least amount of people that have to be there to have at least a 50% chance of having 2 people with the same birthday? and how do you get the answer thank you in advance josh Answered by Harley Weston.
	Rolling a seven		1998-06-11
		From Bruce Thompson: What is the probablity of rolling two dice and it coming out as seven? a) 1/6 b) 1/36 please give me the correct awnser and explain please. Answered by Harley Weston.
	Grade 9 Algebra		1998-06-07
		From Tarah Kostenko: I am a grade 9 student and I cannot figure out how to solve these two similar problems. can you please help? -3(y-1/2)=1/2 also -2/3(x + 1)=6 I don't come up with the same answers as the book and I can't figure out what I'm doing wrong. Thank you, Answered by Harley Weston.
	A Logic Problem		1998-06-07
		From Anthony Bacigalupo: My name is Anthony Bacigalupo and I take Sequential ][ Math and am taking a practice regents. When doing a logic problem, I encountered the following statements, where I am trying to prove P ( I left out steps unrelated to the question).... Answered by Chris Fisher.
	A trig limit		1998-05-28
		From Ann: This problem is a calculus 1 limit problem-high school level. I'm teaching myself calc over the summer and I'm already stumped. find the limit lim sec^(2)[(sqrt2)(p)]-1 p-->0 --------------------- 1-sec^(2)[(sqrt3)(p)] I'm Ann. Answered by Harley Weston.
	Sequences and series		1998-05-27
		From Michael Le Francois: The sum of the first ten terms of an arithmetic series is 100 and the first term is 1. Find the 10th term. The common ratio in a certain geometric sequence is r=0.2 and the sum of the first four terms is 1248 find the first term. Answered by Penny Nom.
	Trigonometry history		1998-05-26
		From Joeseph Huckler: Can you please tell me some history of the trigonometric ratio Tangent? who discovered it? when was it discovered and some other useful info... Answered by Penny Nom.
	A Place Value Curiosity		1998-05-25
		From Ed: I was visiting with an elderly gentleman this afternoon. He showed me this curiosity and then asked if I could explain it to him. Can you provide an explanation of why the 9 or multiple of 9 keeps occurring in this procedure? Choose any number, say 125 and add the digits to get 8. subtract the 8 from the 125 and the result is 117. Add the digits in 117 to get 9. Subtract the 9 from the 117 to get 108. Add the digits in 108 to get 9. If this procedure continues a 9 or a multiple of 9 reoccurs. What is the mathematical explanation behind this happening? Answered by Denis Hanson.
	The Fourth Dimension		1998-05-24
		From Whitney Page: Okay, here goes all my effort to try to explain shat I'm trying to ask of you. It's about something I read in a book called A WRINKLE IN TIME, by Madeline L'Engle. It's called tesser, or tesseract. It talks about first diminsion, a straight line, second diminsion, a flat square, and third diminsion, a square with sides, front and back, top and bottom. I can picture all of that. Then it says that fourth diminsion is when you square the three diminsional square. It also described the fourth diminsion as time. I can't figure out how that can be. Then it says... Answered by Chris Fisher.
	Percentage Question		1998-05-18
		From Eddie Knox: Example: If I have a recipe calling for 16 ounces of 4% vinegar (vinegar which has been diluted with water to a strength of 4%), and all I have on hand is 16 ounces of 5% vinegar, how much water should I add to decrease the strength to 4%, before measuring the 16 ounces to be used. I'll appreciate any insight and help. Thank you so much! Answered by Harley Weston.
	Graph question		1998-05-12
		From Rose Seminary: Why is the point of intersection of two lines the solution to the corresponding system of equations? Answered by Penny Nom.
	Isosceles trapezoid formula		1998-05-12
		From Donna McMullin: The teacher of Gifted and Talented Math has been trying to locate the formula for anisosceles trapezoid and we can't find it anywhere. Could it be the same formula for that of a parallelogram ? Please advise. Answered by Walter Whiteley.
	Area Calculation		1998-05-05
		From Jessica: There's a question I have that I hope you can answer about calculating area. It seems to me that common sense says that if you have say 100 meters of fence, the area you can enclose should be a constant. Yet the math says it is not so. For example if you build a rectangle 10x40 the enclosed area is 400 square meters. But if you build a rectangle 5x45 then the area is 225 square meters, even though you've started with the same amount of fencing. I know this is true, but can anyone explain IN ENGLISH why this is so? Answered by Harley Weston.
	Pyramid		1998-05-04
		From Lisa Nathan: How do you find the area of a pyramid? Answered by Harley Weston.
	Mathematical Arrays		1998-05-01
		From Gene Lanctot: Could someone please explain what a mathematical or arithmetical array is? The array in question is used in grade three math in Ontario. I would also like to know what its purpose is. Answered by Harley Weston.
	Multiplying by Nine - Chismbop Style		1998-04-27
		From Noria Jones: About a year ago a grade 5 teacher at my son's school taught the children how to multiply the 9 times table on their fingers quickly. It was part of a kind of finger math kind of thing... Answered by Patrick Maidorn.
	Logic and Matrix Instruction		1998-04-24
		From Robin Booker: I need assistance with instruction strategies to teach the construction of a matrix, solving a logic problem. Providing instruction in the construction of a simple matrix , no problem. However, I stumpted on this one. Five players were chosen as All Stars at the basketball banquet. Based on the following clues, find the player's name, team, uniform color and number of points scored.... Answered by Harley Weston.
	Mean and Standard Deviation		1998-04-22
		From Kit: i have a problem of maths. i think the level of the question is secondary. question: Find the mean and the standard deviation of the numbers:1, 3, 4, 5, 7. i hope u solve this question. thank you so much! Answered by Harley Weston.
	Using your fingers		1998-04-21
		From Ian Sutherland: My 7-year-old son, in Grade 2, constantly uses his fingers to count.  I know for now this is a useful crutch but at what point should he stop? Answered by Diane Hanson.
	Hour Hand Movement		1998-04-19
		From Chris and Angela Bradley: My wife and I are haveing an argument over the answer to this question, what is the total number of degrees through which the hour hand of the clock moves in 3 hours and 18 minutes? Thanks in advance. Answered by Chris Fisher.
	A Car Wash		1998-04-04
		From Lisa Gotimer-Strolla: Al washes a car in six hours. Fred washes a car in eight hours. How long will it take them to wash a car together? Answered by Harley Weston.
	Seed Problem		1998-03-26
		From Jody A. Johnson: Seed Problem: The height of an amazing plant grown from a seed varies linearly with the time it has been in the ground. After six days it is 6cm tall and after 60 days it is 15.8m (1580 cm) tall. Write the particular equation giving the height as a function of time. Find the intercepts and explain them. What would be the height in one year? How long would it take for the plant to grow to a height of 1km? I'm having a problem with this equation. Could you please help. Thank you. Answered by Penny Nom.
	The day of the week, July 24, 1837		1998-03-21
		From Colleen K.: What day of the week (Mon. Tues. Wed. etc...) was July 24th, 1837? Answered by Chris Fisher.
	Curvature of the Earth		1998-03-16
		From Robert Dyck: How can I find the curvature per mile of the earths surface? What is it? Answered by Harley Weston.
	The Largest Factor		1998-03-15
		From Senthuran Nadarajah: When each expression is evaluated for different values of n, the answers will differ. For each expression, find largest natural number that will divide the result for all natural number values of n. n^5 - 5n^3 + 4n Answered by Harley Weston.
	Matrices		1998-03-10
		From Ksya: A and B are matrices. If A^n=B^n, can we say A=B or det(A)=det(B) or det(A)^n=det(B)^n ? Any conditions ??? If B^(-1) is the inverse of B, where B is a matrices. Can we say [(B^(-1))^n][B^n]=I, where I is identity matrices? Any conditions??? Answered by Doug Farenick.
	Clock Arithmetic.		1998-03-09
		From Joann Dixon: What is clock mathematics? Answered by Patrick Maidorn.
	Area of a Triangle.		1998-03-05
		From Amanda: How do you figure out the area of a triangle? You already have the perimeter and height Answered by Penny Nom.
	Y-intercept		1998-02-27
		From Don Trumpet: What is the Y-intercept for the problem:Y = -2(x+2) + 9 Answered by Harley Weston.
	Pay Phone Problem		1998-02-26
		From Shameq: Hi, I've been given a problem that I'm having some trouble with. I'd really appreciate any help. Here's the question (it's called the Pay Phone Problem) A pay phone will take only 10p, 20p, 50p, and £1 coins"(It's British). A woman has plenty of 10p and 20p coins. She has no other coins. She can put the coins into the pay phone in any order. INVESTIGATE the number of different ways, she could put the 10p and 20p coins into the pay phone. Answered by Penny Nom.
	The origin of angles		1998-02-24
		From Marc Poulin: I'm currently teaching angles to students in grade 10 and I've been asked what's the origin of the terms degrees, radians and gradians. I know that the radians come from the sexagesimal numerical system of the Babylonians but my kids wanted to know dates and persons who would have brought these terms first. Answered by Harley Weston.
	Tessellations of non-polygons		1998-02-24
		From Ellen Goldwasser: Hi! My name is Ellen Goldwasser. I'm a seventh grade student and I'm doing a prodject on tessellation. My question is: why will certain shapes (not polygons) tessellate? Thanks for your help! Answered by Penny Nom.
	Tangrams		1998-02-24
		From Allison: Do you know the story behind the tangram? I know that it is a Chinese puzzle about 200 years old. If there is a story about its creation, I would love to share it with my 7th graders. Thanks. Answered by Diane Hanson and Penny Nom.
	(50^20)(20^50)		1998-02-24
		From fion: 50 power of 20 X 20 power of 50? How many zero can be found in the answer and why? Answered by Penny Nom.
	x^2 = ...444		1998-02-23
		From James Bauer: What is the first interger that when squared ends in three 4's? (ex. x^2 = ...444) Prove that there are no intergers that when squared end in four 4's (ex. x^2 = ...4444) Answered by Penny Nom.
	A Tightrope Walker.		1998-02-19
		From Amy Zitron: A tightrope is stretched 30 feet above the ground between the Jay and the Tee buildings, which are 50 feet apart. A tightrope walker, walking at a constant rate of 2 feet per second from point A to point B, is illuminated by a spotlight 70 feet above point A.... Answered by Harley Weston.
	The sum of the angles of a triangle is 180 degrees		1998-02-19
		From Quin Liu: How do you prove that the sum of the angles of a triangle is 180 degrees? Is there a proof? what is it? Answered by Chris Fisher.
	Graph Distortion		1998-02-19
		From Dana Steffan: What exactly is graph distortion? I have to explain it for a project and I can't seem to find anything on it. Answered by Penny Nom.
	Intersecting Lines.		1998-02-10
		From Erik Heppler: My typewriter frequently makes mistakes. Suppose I gave you the following system of equations to solve: 35.26X + 14.95Y = 28.35 187.3X + 79.43Y = 83.29 When I looked back, I realized that I meant to use 14.96 as the "Y" coefficient in the first equation instead of 14.95. Solving the system using 14.95 and then solving another system using 14.96 with all other values the same both times results in the intersection points (1776, -4186) and (-770, 1816) respectively. How can that be? Answered by Penny nom.
	The Earth's Arc		1998-02-06
		From Robert Dyck: How do I find the arc/mile of the earths surface? What is the arc? Answered by Harley Weston.
	Roman Numerals		1998-02-05
		From Dawn Hilgenberg: How would I read a Roman Numeral such as LXII? Does the L in front make the X equal a lesser amount? We have been discussing how to read these and I can find no information about how to read an extended Roman Numeral problem. Help!! Answered by Harley Weston.
	Area of a triangle.		1998-02-01
		From Jodi Blucher: Is there a formula for the area of an equilateral triangle knowing the length of the sides? Answered by Chris Fisher and Harley Weston.
	Two Inscribed Trapezoids		1998-01-27
		From James: A hexagon inscribed in a circle has three consecutive sides each of length 3 and three consecutive sides each of length 5. The chord of the circle that divides the hexagon into two trapezoids, one with three sides each of length 3 and the other with three sides each of length 5, has length equal to m/n, where m and n are relatively prime positive integers. Find m+n. Answered by Haragauri Gupta.
	Divisors of 6n		1998-01-26
		From James: If n is a positive integer such that 2n has 28 positive divisors and 3n has 30 positive divisors, then how many positive divisors does 6n have? (a) 32 (b) 34 (c) 35 (d) 36 (e) 38 Answered by Penny Nom and Haragauri Gupta.
	The two-digit numbers from 10-99		1998-01-21
		From Alexis Riddle: My name is Alexis. I'm a student in 8th grade and I'm taking Algebra I Honors. My question is: In a string of numbers, two adjacent digits are considered as a two-digit number. For instance, the string 11012 contains the numbers 10, 11, and 12. What is the number of digits in the smallest string that contains all of the two-digit numbers from 10-99? Please help and thank you for any assistance you can give me. Answered by Penny Nom.
	The Factor Theorem		1998-01-18
		From Dhruv Bansal: Hi, I'm a ninth grade student doing a math project for school. I'm trying to learn about various ways of solving 3rd and 4th degree polynomial equations using the remainder theorem, the factor theorem, and synthetic division. The books I have all mention x - r, which I know nothing about, not even how to get it. I would really appreciate any information on this. Thanks. Dhruv Bansal Answered by Penny Nom.
	Polynomials		1998-01-13
		From Sarah Storkey: Hi, My name is Sarah, My question is at the junior level. My question is, what is a polynomial? Answered by Harley Weston.
	Quadratic Graphs		1998-01-13
		From Simon Batten: How does varying the values a,b and c affect the graph of y=ax2 + bx + c? Answered by Harley Weston.
	Greatest Common Factor.		1998-01-09
		From Percy Stribling: how do you figure out what the greater common factor is? Answered by Penny Nom.
	Bathtub		1998-01-04
		From Jeffrey Yau: A bathtub, with two taps, can be filled in 20 minutes using only the cold water tap. It can be filled in 30 minutes using only the hot water tap. The flow of each tap is not changed when both taps are turned on. It takes 24 minutes to drain the full tub. Starting with an empty tub and the drain plug in place, the cold water turned on. Five minutes later the hot water is also turned on, and five minutes after that the drain plug is removed. How many additional minutes, after the plug is removed, would it take to fill the tub? Answered by Harley Weston.
	Find the Numbers.		1997-12-28
		From Sandy C: The sum of the squares of two numbers is 53. Twice the greater, minus the lesser is 11. Find the numbers. Answered by Penny Nom.
	Trigonometric functions		1997-12-21
		From Calvin Cheng: My name is Calvin and I have a year 12 question for you to help me with. From a point S, the angle of elevation of the top of a tower due north of it is 20 degrees. From R, due east of the tower, the angle of elevation is 18 degrees. S and R are 100m apart. Find the height of the tower. Answered by Harley Weston.
	(-2)^x		1997-12-12
		From Ken Bokinac: During our math class last week we came accross an equation that we could not graph we were wondering if you could help us try and graph it. The question is: y=(-2)^x Answered by Harley Weston.
	Calculating the Intersection Point.		1997-12-10
		From Milton Parsons: Given 2 lines through (x1,y1),(x2,y2),and (x3,y3),(x4,y4). Can you give me a good formula for calculating the intersection point. I would greatly appreciate it.Thanks. Answered by Chris Fisher and Penny Nom.
	Pythagorean Triples.		1997-12-04
		From Shameq Sayeed: I've got a couple of problems which I hope you'll be able to solve for me. I'm investigating pythagorean triples, and I have found a trend for the triples themselves, and thus have been able to form a general equation, i.e. a=2x+1, b=2x^2+2x, and c=b+1. Now, I sure this equation works, because I've tried it out and have come up with triples that adhere to a^2 + b^2 = c^2. But I was wondering WHY c=b+1. Is it possible to have c=b+2, and if not why not? THAT is the first problem. Answered by Chris Fisher.
	Shimin's Geometry Problem		1997-12-02
		From Ong Shimin: ABCD is a rectangle. X and Y are the midpoints of BC and CD respectively. W is a point on AB such that AW : WB = 2 : 1. Z is a point on AD such that AZ : ZD = 2 : 1. WY intersects XZ at O. If the area of triangle WOZ is 84 centimeters squared, find the area of triangle XOY. Answered by Chris Fisher.
	Limited area and unlimited perimeter.		1997-11-28
		From Rosa: There is a figure, it has unlimited perimeter but has limited area , what is the figure and how to draw it ? Thank you very much! Answered by Harley Weston.
	Ratios.		1997-11-26
		From Jennifer Kim: I am a grade 12 math student who would like to know if there is an easy way to solve In a school the ratio of the number of Grade 11 students to the number of grade 12 students is 4:3. If there were 5 fewer students in grade 11 and 3 more students in grade 12, the ratio would be 7:6. How many students in each grade? Answered by Penny Nom.
	A Problem with Logs.		1997-11-26
		From Herman: Given log 24=a, log 25=b and log 26=c, express log 39 in terms of a, b and c. Answered by Penny Nom.
	Guess and Check		1997-11-25
		From Don Ramey: Hope you can help !!!! my daughter is in the 4th grade.. she has brought home a homework paper and the subject is problem solving. she does not understand what is expected of her. I have tried to help, but I do not understand either. She is to use the Guess and check Strategy. Ben knows 100 of his neighbors by name. Ten are fish. The rest are frogs and turtles. He knows the names of twice as many turtles as frogs. How many turtles does he know by name.? Please help by explaining the guess and check strategy for a problem like this. Answered by Diane Hanson.
	Division by a fraction.		1997-11-21
		From Roger Marchegiano: I am interested in a solution to the following extra credit problem for my son in Geometry. We have been unable to produce a satisfactory response: Show a geometric representation of the division of fractions algorithm, (When you divide fractions you multiply the numerator by the reciprocal of the denominator). Answered by Penny Nom.
	A geometry problem		1997-11-20
		From Herman: When produced, two equal chords AB and CD of a circle meet at P in an angle of 24 degrees. If H is the mid-point of AB and K is the mid-point of CD, calculate the size of angle HKD. Answered by Penny Nom.
	Driving me CRAZY.		1997-11-17
		From Billy Tran: Write a two digit number (both digits different and neither equal to zero) and then express the same number but now composed of the same two digits in reverse order with some mathematical symbol (+, -, *, /, roots, !, or exponents). for example: 25 = 5^2. Now give me another. Hope you get this, cause its driving me CRAZY Answered by Penny Nom.
	Octants		1997-11-10
		From Jason Watkins: I know which octant is octant 1 because all variables are positive. How do we number the other octants? Answered by Harley Weston.
	Negative Primes.		1997-11-10
		From Leah Zucker and Paul Michael: I have received the following question via e-mail from my granddaughter: "Can negative numbers (like -7) be prime? If not, why not?" Answered by Chris Fisher.
	Multiplying imaginary numbers.		1997-11-03
		From Jim Catton: Here is the question: (square root -2) x (square root -8) My algebra suggests two possibilities . . . Answered by Walter Whiteley, Chris Fisfer and Harley Weston.
	Pi		1997-10-31
		From Ryan McKinnon: What Is Pi? Answered by Chris Fisher.
	Roman Numerals		1997-10-31
		From Mark Curts: I am looking for some resources for teaching Roman Numerals. I would like to expand upon the basic concepts, by locating some addition, subtraction, multiplication or division problems written with Roman Numerals. -- Mark Curts Answered by Chris Fisher.
	Some Calculus Problems.		1997-10-30
		From Roger Hung: What real number exceeds its square by the greatest possible amount? The sum of two numbers is k. show that the sum of their squares is at least 1/2 k^2. . . . Answered by Penny Nom.
	Two Questions		1997-10-28
		From Melissa Kelley: I would appreciate any help you could give me. Why isn't 1 a prime number? How can the absolute value of a number be negative? Answered by Penny Nom.
	Fractions		1997-10-20
		From Rebecca Henry: When we add fractions, we find a common denominator and add the numerators When we multiply fractions, we simply multiply both numerators and denominators with no regard to commonality. Why do we not have to find a common denominator when multiplying? Why do we multiply both numerators and denominators? Answered by Chris Fisher.
	Diagramming Powers		1997-10-15
		From David Fill: I am a teacher in Massachusettes. We have been diagramming numbers such as two to the third (a 3-D cube). One of my students asked me how you would diagram two to the fourth. I have searched through all of my teachers books and cannot seem to find the answer to this question. Is there a way to diagram this? If there is, how would you do this? Your help would be greatly appreciated. Answered by Penny Nom.
	How many intersections?		1997-10-08
		From James: (a) A collection of eight points, no three collinear. If lines are drawn between each pair of these points, how many points of intersection would there be? (b) what would your answer have been in part (a) if there had been n points to start with? Answered by Chris Fisher.
	Polynomials		1997-10-07
		From Sheryl and Jeff: I'm a math teacher in Jerusalem, Israel. I'm teaching about graphing polynomial functions in a pre-calc class. A student asked me what they're good for. I couldn't give her a good example. Do you have one. Thanks. Answered by Penny Nom.
	Histograms.		1997-09-26
		From David Wilson: I need some help to teach my daughter the functions and the techniques involved in solving histograms. She is in the 7th grade and is in a prealgebra class. She was give these as homework, however there is no section in her book explaining what a histogram is or how to solve them. Thanks! Answered by Penny Nom.
	Cos(x) Cos(2x) Cos(4x)=1/8		1997-09-24
		From Tan Wang: How many distinct acute angles x are there for which cosx cos2x cos4x=1/8? Answered by Chris Fisher Harley Weston and Haragauri Gupta.
	A Geometry Problem		1997-09-18
		From Rebecca Henry: A circle is centered at the vertex of the right angle of an isosceles triangle. The cirlce passes through both trisection points of the hypotenuse of the triangle. If the length of a radius of the circle is 10, find the area of the triangle.  Answered by Chris Fisher Harley Weston.
	A Trigonometric Limit		1997-09-18
		From Brian Ray: What is the limit, as x approaches 0, or tan^23x/x^2? (read, tan squared 3x over...)? Answered by Harley Weston.
	Imperial System of Measurement.		1997-09-17
		From Judy Pardilla: Please also give the solution to the answers. Thank you.   If a room is 12 feet by 15, how many square yards are there?   If a single roll of wallpaper will cover 30 square feet, how many single rolls will it take to cover a wall 8' x 15'?   If ceramic tiles are 8" x 8", how many tiles would it take to cover an area 4' x 6'? If possible, can you e-mail me a table for imperial measurements. Thank you! Answered by Penny Nom.
	Rowing on the Charles River.		1997-09-17
		From Fawwaz Muraisi: On the Charles River in Boston, the Harvard bridge and the Longfellow bridge are 1 mile apart. The MIT crew starts rowing upstream at the Longfellow bridge. As the crew passes under the Harvard bridge, the coxswain's hat falls into the river. Ten minutes later, the coxswain notices and turns the boat around instantaneously. He has t he crew row back to get it, rowing at the same constant rate. By the time the team reaches the hat, they are back at the Longfellow bridge. How fast is the river flowing? Answered by Harley Weston.
	A Limit Problem		1997-09-16
		From Robert Reny: what is the limit, as x approaches 0, of 3x/2x-[x]? [] means absolute value. Answered by Harley Weston.
	Billions and more!		1997-09-15
		From Mahabir B. Gupta: I would like to know how you americans write the number 1 billion. Do you say "One thousand million"..can you answer by giving me examples? 1,000,000----> 1 million 1,000,000,000---->1 billion Why is it that in spanish it is different? Answered by Penny Nom.
	Integer Problems.		1997-09-15
		From Eric Kowalsky: I have some intergers I can't solve. Please help me solve them! Please show me how you got the answer.  5(-4)-[3(-6)+(-3)-4(2(-4)-7)]+3(-8)=  -2[-7-3(4)+5-2(-1)]+3(-6+8)=  4[-6(-2-7)-5(7+2)]=  -7(-4)-2[-3(-4+6)+6(7-3(-4))] P.S. Thank you very much. Answered by Harley Weston.
	The Range of a Function.		1997-09-12
		From Karel Marek: Math Is Book 6 (Ebos/Tuck) question 5(b) gives a surprising answer at the back of the book.. The question is: Indicate the domain and range for this: y = sqr(x-9) (Square root of) The answer for the domain is x>=9 which is not surprisingly, but the range is y>=0, yER ... which I could understand if you were not allowed to transform the equation into x as the subject.. But all example on the facing page DO TRANSFORM the equation at will with x and/or y as the subject.. Can you explain this... ?? Answered by Chris Fisher.
	Triangular Numbers.		1997-09-08
		From Rachel: Show visually that the square number 16 is the sum of two triangular numbers. Which two? Answered by Penny Nom.
	Definitions		1997-09-08
		From SohoGirl13: I am an 8th grader. my e-mail address is SohoGirl13@aol.com. I have a question: what are the associative, communitive, and distributive properties? Answered by Harley Weston.
	A Finite Math Question.		1997-09-07
		From Angela L.: How many three-digit numbers can be formed using only the numbers 1 to 7 if the number 2 must be included? Answered by Penny Nom.
	Prime Numbers		1997-09-04
		From Jack Bedard: Hi. I have a real stupid question What are prime numbers? My name is Jack Bedard and I am in grade 5. Answered by Penny Nom.
	Square Root History		1997-08-29
		From Carlos Montecel S.: I need find information over the "Square Root History", Could you help me? Answered by Harley Weston.
	Two Questions		1997-08-28
		From Faye Tan: I am a trainee teacher. I would appreciate it very much if you could help me solve the following two problems which I think are meant for students at middle grade. 1. If a hen and a half lays an egg and a half in a day and a half, how many hens are needed to lay a dozen eggs in one day? 2. There are fewer than 200 passengers on a train. If they get off in pairs, one passenger will be without a partner. If they get off in groups of 3 or 4, there will still be one passenger left by himself. However, if they get off in groups of 5, no one will be left by themselves. How many passengers are there on the train? Answered by Penny Nom.
	The Length of a Chord.		1997-07-26
		From Nathan Arthur: Picture a 9 inch diameter circle. Inside that circle is a 6 inch diameter circle tangent to it. Then, tangent to both circles is a 3 inch diameter circle. So there are three circles, two smaller ones inside a big one, all of them just touching but not overlapping. Now picture a chord on the 9 inch circle that is created by making a line that is tangent to both the 6 and the 3 inch circles and extending it to the edge of the 9 inch circle. I need the length of that cord. Answered by Chris Fisher.
	A Question About Pi.		1997-07-08
		From Mike Chan: I have read the section Repeating Decimals in your data base. It mention that 1/17 has at most only 16 repeating digits. But, why does "pi" have an infinite number of digits (and not repeating ). Answered by Penny Nom.
	Finding the Mine		1997-06-23
		From Billy Law: Tom is gold prospector. On his last trip out from town, he headed 35 degree South of West to a lake where he had lunch. The lake was 24 km out of Town. He then headed due East for 35 km before Doubling back on bearing of 15 degree South of west for 20 km to reach his mine. By converting to Cartesian coordinate before doing vector additions do the following: a) Calculate the position of the mine from town in term of a distance and a direction. ... Answered by Harley Weston.
	A problem with arccos.		1997-06-09
		From Vanessa Chan: Prove: arc cos4/5 + arc cos (-5/13) = arc cos (-56/65) Answered by Harley Weston.
	The angle between two tangents.		1997-06-09
		From Felix Ho: Two tangents are drawn from the origin to the circle (x)(x)+(y)(y)-4x-6y+9=0. If the angle between the tangents is m, fine the value of tan(m). P.S. (x)(x)=square x Answered by Harley Weston.
	Y-axis		1997-05-29
		From Leah: I know that the proper name for the X axis is the abscissa, but, what is the proper name for the Y axis? Answered by Chris Fisher.
	The General Equation of a Parabola		1997-05-28
		From Michelle: My name is Michelle and I am a 10th grade student in algebra 2 w/ analysis. I am doing a report on parabolas and I need to know what the general equation is. I've looked in books and keep finding different ones! I also need to know how they can be used in nature. Thank you so much for your time. I really appreciate it! - Michelle Answered by Harley Weston.
	The Area of a Trapezoid.		1997-05-07
		From Mary George: I am doing the area of trapezoids and mixed polygons and I was wondering if you can help me figure out this problem. A line segment drawn parallel to a leg of a right triangle divides the other leg into segments of 3cm and 6 cm and the hypotenuse into segments of 5cm and 10 cm. The two figures formed are a triangle and a trapezoid. Find the area of each. I would appreciate if you would email me back the solution. Answered by Harley Weston.
	Surface Area		1997-04-30
		From Amber Nobile: The height of a cylinder is twice the diameter. Express the total surface area as a function of the height h. Answered by Harley Weston.
	A proof that e is Irrational.		1997-04-30
		From Peter Hall and Jenny: We have a little mathematical problem... we need some help proving e is an irrational number! We don't feel very confident in our formulas, so if You have the time to give us a little explanation we would be very grateful!!! Answered by Doug Farenick and Penny Nom.
	Solving a Trig Equation.		1997-04-28
		From Susan Harvey: Hi I am a teacher and have a calculus problem that I have a solution to but it seems so involved that I would be interested to see if their were other solutions. Solve for x, if x is from -90 to 90 degrees tan2x = 8cos{squared}x - cotx Answered by Chris Fisher Denis Hanson and Harley Weston.
	Formulae for Surface Area.		1997-04-28
		From Gary Millward: I'm trying to help my son with his Math homework (Grade 10) and he has to find the surface area of a cone and rectangluar pyramid. We have the formulas for the volume of these solids, but can't seem to locate the formulas for surface area. Answered by Walter Whiteley.
	A Monte Carlo Procedure		1997-04-23
		From Donna Hall: A irregularly shaped object of unknown area A is located in the unit square 0<=x<=1. Consider a random point uniformly distributed over the square. Let X = 1 if the point lies inside the object and X = 0 otherwise. Show that E(X) = A. How could A be estimated from a sequence of n independent points uniformly distributed over the square? How would you use the central limit theorem to gauge the probable size of the error of the estimate. Answered by Harley Weston.
	Natural Logarithm Functions		1997-04-23
		From Rickson: The following two questions are some of my son's homework that he is having trouble with......any advice or assistance would be appreciated. (eX)5=1000.............the X and 5 are exponents lnx + ln(x+3) = ln10 In each question the problem is to find x. Answered by Harley Weston.
	Square Roots and Functions.		1997-04-23
		From Ed: 1. In most texts the solution to a question such as square root x = -6 is x is undefined. Yet when teaching to solve xsquared = 36 x = +6 or -6 There appears to be a contradiction here. My question is when, where and why do we use the principle square root, not both + and -? This often occurs as the extraneous root in the solution of radical equations and in stating the domain and range of functions involving square roots. 2. Are there any simple rules for determining whether equations are functions without graphing them and doing a vertical line test? Answered by Harley Weston.
	The Central Limit Theorem		1997-04-21
		From Donna Hall: A skeptic gives the following argument to show that there must be a flaw in the central limit theorem: We know that the sum of independent Poisson random variables follows a Poisson distribution with aparameter that is the sum of the parameters of the summands. In particular, if n independentPoisson random variables, each with parameter 1/n, are summed, the sum has a Poisson distributionwith parameter 1. The central limit theoren says the sum tends to a normal distribution, butPoisson distribution with parameter 1 is not normal. What do you think of this argument? Answered by Neal Madras.
	Proofs		1997-04-13
		From Daniel: I'm having trouble understanding proofs. I don't know how to come up the answers on my own. I search through the book looking for the answer. I understand what they are doing, but I don't know how to do it. Answered by Walter Whiteley.
	The Division Bracket.		1997-04-09
		From Judy Riley: A fellow teacher recently asked if I remembered the exact word for a division bracket (not the symbol with dots, the horizontal line in a fraction, or a solidus). I couldn't. Can you help? Answered by Walter Whiteley and Harley Weston.
	A Geometry Problem		1997-04-09
		From Gina M. Pisco and Rebecca Henry: Three segments of 3, 4, and 5 inches long, one from each vertex of an equilateral triangle, meet at an interior point P. How long is the side of the triangle? Answered by Richard McIntosh.
	Equation of a line		1997-04-08
		From Susan Gregson: I am a secondary school teacher. My students and I would like to know why the letters m and b are traditionally used to stand for slope and Y-intercept in the standard form of an equation. Was this an arbitrary choice? Who made it? Are the letters from Greek ot Latin words? Answered by Harley Weston.
	Graphing Inequalities of Conic Sections		1997-03-24
		From James Sheldon: I'm trying to graph Systems of Conic Sections with inequalities, but I'm running into problems on which area to shade: x^2+y^2 is greater than or equal to 16 xy > 4 So I graph these two equations, and then my teacher said to substitute a point into it but I'm still not sure how to do it... Answered by Penny Nom.
	The normal distribution.		1997-03-21
		From Donna D.Hall: I am looking for a proof for the normal distribution. I suppose "proof" was not a good choice of words. What I am looking for is a way to "derive" the normal distribution in simple terms so that the most average teenager can see the logic. Can you help me? Answered by Harley Weston.
	Why QUADratic?		1997-03-19
		From Paula Miller: A student today asked me why a quadratic, with highest power of degree 2, was called a QUADratic. We're awaiting the answer with baited breath! :) Answered by Chris Fisher and Walter Whiteley.
	Mathematical Induction and the Derivative		1997-03-18
		From Shuling Chong: "Obtain a formula for the nth derivative of the product of two functions, and prove the formula by induction on n." Any educated tries are appreciated. Answered by Penny Nom.
	A Presidential Proof		1997-03-18
		From Greg Smith: Which US president developed a proof for the Pythagorean Theorem? Where can a copy of the proof be located? Answered by Chris Fisher and Harley Weston.
	The Real Pythagoras		1997-03-16
		From Michael Gaskin: I am wondering if you have any information about Pythagoras and his accounts in math. Answered by Chris Fisher.
	Ajax, Beverley, Canton and Dilltown		1997-03-14
		From S. Johnson: The following towns are placed on a coordinate system. Ajax at (-x,z), Dilltown at (-10,0), Canton at (0,0) and Beverly at (0,10). The roads from Beverly to Canton and from Canton to Dilltown are perpendiculat to each other and are each 10 miles in length. A car traveling at all times at a constant rate, would take 30 minutes to travel straight from Ajax to Canton, 35 minutes to travel from Ajax to Canton via Beverly, and 40 minutes to travel from Ajax to Canton via Dilltown. What is the constant rate of the car, to the nearest tenth of a mile per hour. Answered by Chris Fisher and Harley Weston.
	Names of the Polygons		1997-03-04
		From Manuel: What do you call a 13 sided polygon? Is there a list of the different names? Answered by Walter Whiteley and Harley Weston.
	0!		1997-03-02
		From Donna D. Hall: I am looking for a quick and easy explanation as to why 0! is 1. Answered by Walter Whiteley and Denis Hanson.
	Area Between Two Sectors		1997-03-02
		From Rebecca Henry: Points A,B,C,D,E,F are equally spaced on a unit circle. Arc CGE has a center A. Find the number of square units of area in the shaded region. Answered by Walter Whiteley.
	A Functional Equation.		1997-02-26
		From Ronald Lui: Find all functions f:S --> S statisfying the two conditions: 1)f(x+f(y)+xf(y))=y+f(x)+yf(x) for all x and y in S 2)f(x)/x is strictly increasing on each of the interval -1 Answered by Saroop Kaul and Chris Fisher.
	Equivalent Expressions		1997-02-26
		From Karyn Jones: Josie says that s=n/(n+1) and s/(1-s)=n are two ways to write the same formula. Describe whether or not you agree with Joise. Explain how you made your decision. Answered by Walter Whiteley and Penny Nom.
	Some Circle Questions.		1997-02-25
		From Staci Vawser: A circle with a radius of 10m is drawn. A chord is drawn across the circle. How is the area that is formed between the chord and the arc calculated? Answered by Harley Weston.
	Triangles, The Pythagorean Theorem and Pizzas.		1997-02-23
		From Sherryle Mathis: I am a graduating senior presently teaching geometry as part of my student teaching. I will do my CUP on Right Triangles and Pythagorean theorem. I am looking for a fun activity as part of my unit plan. Answered by Walter Whiteley.
	Division by zero		1997-02-14
		From Linda Hood: I am a college student and have been asked to explain and figure out why we can't divide by zero. Answered by Chris Fisher.
	When is ( n^3+1)/(mn-1) an integer?		1997-02-11
		From Ronald Lui: Determine all ordered pairs (m,n) of positive integers such that ( n^3+1)/(mn-1)is an integer. Answered by Richard McIntosh.
	Circular Permutations		1997-02-05
		From Ed Varjassy: I have an understanding of simple problems involving circular permutations but do not understand them when they start to have restrictions. Is there any advice you can give for these more complicated permutations. Answered by Penny Nom.
	Deriving the Quadratic Formula		1997-02-04
		From James: How do you derive the quadratic formula? I know what it is, but the textbook doesn't say how to derive it. Answered by Penny Nom.
	Parabolic Mirrors		1997-01-28
		From Megan Wennberg: Consider a ray of light that passes through a chord of a parabola (the chord is above the focus and parallel to the directrix), hits the parabola at a point (x,y) and is reflected through the focus. If d1 is the distance from the chord to the point of incidence (x,y) and d2 is the distance from (x,y) to the focus, can you prove that the sum of the distances d1+d2 is constant, independent of the particular point of incidence. Answered by Penny Nom.
	A donkey and his carrots		1997-01-28
		From Emily Lind: There is a donkey who carries carrots. A farmer has 3,000 carrots to carry to the market. The market is 1,000 miles away. The donkey can only carry 1,000 carrots at a time and he eats 1 carrot every mile that he walks but this is only when he is carrying carrots. How many carrots can the farmer get to market by having the donkey carrying them? Answered by Penny Nom.
	Repeating Decimals		1997-01-24
		From Grant Reed: Is there a way to tell that the repeating decimal for 1/17 has no more than 16 repeating digits? Answered by Penny Nom.
	Foci of an Ellipse		1997-01-22
		From David Gilliam: How do I find the focii of the following equation? 4x^2 + 9y^2 = 36 Answered by Harley Weston.
	Mathematics of Schedules		1997-01-16
		From Byron Krull: I was asked if there was a mathematical method to work with schedules. The problem is this. There are 24 teams playing weekly on 4 sheets at 3 different times of the day as follows... Answered by Denis Hanson.
	Three Spheres		1997-01-14
		From Alan Schnerch: Three spheres of diameter 2 are placed on a level surface so that each sphere touches the other two. A fourth sphere, also of diameter 2, is placed on top of the other three so that it touches all of the other spheres. The distance from the level surface to the highest point of the top sphere is . . .. Answered by Chris Fisher and Harley Weston.
	A triangle problem		1996-12-19
		From S. Johnson: Given that Triangle ABC is a right triangle and Circle O is inscribed in it find the radius of Circle O, totally in terms of a, b, and c. Answered by Penny Nom.
	A trig problem		1996-12-13
		From S. Johnson: sin t + cos t = 1/5. Find ALL exact values of cot t, given the original equation. Answered by Harley Weston.
	Roots of a Polynomial		1996-12-06
		From Paula Miller: Why is the solution called a "root"? Why not just the "x-intercepts"? Answered by Chris Fisher and Harley Weston.
	Sides in a Regular Polygon		1996-12-06
		From Rick Moss: If you are given the measure of each interior angle (162 degrees) of a regular polygon. How many sides does the polygon have? Answered by Penny Nom.
	A balance problem		1996-11-18
		From Jack N. Bussell: There are 12 coins which look exactly the same, however one of them is heavier or lighter than the rest. Using a pointer balance scale, can you identify the odd coin and whether it is heavy or light in 3 weighings? Answered by Harley Weston.
	Pentominoes		1996-11-14
		From Sam Maraldo: What is a pentominoe? I need to understand the concept and how/why it is used? Answered by Penny Nom.
	Trigonometry		1996-11-12
		From Evans: Any idea who came up with some or most of the ideas involved in trigonometry? Answered by Chris Fisher.
	Smith, Rodriguez and Jones		1996-11-07
		From Rafayel Ambartsumyan: On a train, Smith, Rodriguez, Jones are the fireman, brakeman, and engineer, but not in that order. Also aboard the train are three businessman who have the same names, a Mr. Smith, a Mr. Rodriguez, and a Mr. Jones. ..... Who is the engineer? Answered by Penny Nom.
	Height of a Hotel		1996-11-07
		From Irene: "Irene" is to determine the # of floors in a hotel 500 feet up the street. Irene is on the 10th floor of an office building and can measure the angle of elevation to the top of the hotel, 57 degrees. Her view of the entire building is obstructed. If the street rises at an angle of 8 degrees from the office building to the hotel and the average distance between floors is 11 feet, how many floors are on the hotel? Answered by Penny Nom.
	Common Area of two sectors.		1996-11-06
		From Lynda Mow: How do I find the area common to two intersecting circles of radii 8 ft and 10 ft if their common chord is 10 ft long? Answered by Penny Nom.
	Priority of operations		1996-11-04
		From Wallace: What is the answer to this problem? Let x=-2 and y=3. Evaluate 12x / 2y (if the old division sign is used). Answered by Chris Fisher.
	Approximating pi.		1996-11-04
		From Ben Dixon: How do you calculate Pi? Do you have to somehow combine the equation for a circle with the formula for the circumference? Answered by Chris Fisher.
	Approximating roots.		1996-11-04
		From Ben Dixon: How do you calculate a square root? eg the square root of 2. There is obviously some sort of successive approximation type algorithm for doing it to however many decimal places is required, but what is the algorithm? Answered by Harley Weston.
	The diameter of the sun.		1996-10-29
		From Lynda Mow: What is the process for solving the following question? As viewed from earth, the sun subtends an angle of approx 32'. If the sun is 93,000,000 miles from earth, find the diameter of the sun. Answered by Penny Nom.
	A tangent to a circle is perpendicular to the radius at the point of contact.		1996-10-22
		From Rita Leung: I wonder if there is any proof for this theorem - A tangent to a circle is perpendicular to the radius at the point of contact. If there is any proof for that, can you tell me please? Answered by Chris Fisher and Harley Weston.
	Could you tell me the name for the bar in a division problem?		1996-10-21
		From Linda: Could you tell me the name for the bar in a division problem. Not the line with dots on either side but the line that divides the two numbers? My name is Linda. I am asking for my niece who is in 8th grade. Answered by Chris Fisher.
	What is the volume of a regular tetrahedron?		1996-10-21
		From Paul Bleier: How does one calculate the volume and the height of a three sided pyramid formed by equilateral triangles? Answered by Bruce Gilligan.
	How many digits are there in 2^2520?		1996-10-07
		From Rita Leung: A)The number 64 is a sq., a cube, and a sixth power because 64=8*8, 4*4*4, 2*2*2*2*2*2. Find the smallest integer greater than 1 that is a sq., a cube, a 4th, 5th, 6th, 7th, 8th, 9th and 10th power. I have found that the answer is 2 to the power 2520th. B) How many digits are in the correct answer to part A? The answer is uncertain. It is either 758 or 759. Can you give me any ideas? Answered by Penny Nom.
	Why is lbs the abbreviation for pounds?		1996-10-03
		From Nancy Mutdosch: What does lbs stand for? Why is it the abbreviation for pounds? Answered by Chris Fisher.
	Why is a circle divided into 360 degrees?		1996-09-30
		From Kurtis Kredo: I was recently wondering why a circle has been divided in to 360 degrees. When I asked my physics teacher he could not think of an answer. His guess is that it probably has to do with people long ago using the base 6 number system. I have a small inkling that it has to do with easy conversion or usage with radians or grads. Answered by Chris Fisher.
	Divisibility of 2n choose n.		1996-09-24
		From Kathy Doan: Can you prove that "2n choose n" is not divisible by 3, 5, and 7 for infinitely many n? Answered by Penny Nom.
	How many possible combinations of answers are there?		1996-09-20
		From David Bester: Suppose there is a 12 question test. Each question can be answered only by true or false. Assuming that all questions are answered (i.e. none are left blank), how many possible combinations of answers are there? And what formula was used to arrive at the answer? Answered by Denis Hanson.
	Term definitions		1996-09-18
		From M. Seltzer: A 7th grade algebra student would like the definition of the terms proper factor and perfect number. Answered by The Centralizer.
	How do you find out if a number is a composite or prime?		1996-09-16
		From Trish Feenstra: Hi my name is Trish Feenstra. In grade 8. How do you find out if a number is a composite or prime if it is big like 37 529? Reply soon got a test on Friday the 13th Answered by Denis Hanson.
	Repeating decimals		1996-09-09
		From Alice: What is the line called that is placed over the decimal to show that it is infinitely repeating? Answered by The Centralizer.
	Will this always yield a palindrome?		1996-08-28
		From Andy Golden: My friend Justin Skywatcher, said that when his children were in 6th grade, they were taught that if you take any number, reverse it and add the two together, a palindrome will result. If not, continue performing the above operations, and a palindrome will eventually result. Will this always yield a palindrome? Answered by Chris Fisher.
	Thousands, millions, billions and trillions		1996-08-22
		From Blaine: What are the names of the periods in groups of numbers like 123,456,789. I need to know the names of them for school. I already know the first ones: units thousands millions billions trillions. Answered by Penny Nom and Diane Hanson.
	Where do 2^x and x^2 intersect?		1996-07-23
		From Darin M Selfridge: The intersecting points of y=2^x and y=x^2, graphed along with x^2=2^x, are obviously three... (2,4), (4,16) and (?,?). I am having problems figuring out the value, and even an equation for the (?,?). Can you help? Answered by Harley Weston Chris Fisher.
	How do you raise a number to an imaginary/complex power?		1996-07-03
		From Andy Golden: How do you raise a number to an imaginary/complex power? I know how you raise "e" to a complex power, like e^(pi*i): cos pi + i * sin pi But what about numbers other than "e"? What if I want to raise 5 to the 2i power? How is that done? Answered by Chris Fisher.
	What are fractals and are they of any practical use?		1996-06-26
		From Ron: What are fractals and are they of any practical use? Answered by Chris Fisher.
	Diagonals in a polygon		1996-06-18
		From Steven: How many diagonals are there in a polygon? Answered by Denis Hanson.
	Show that this construction yields a rhombus.		1996-06-16
		From LennyB: Hello, I have a problem. I doubt you can help me. If you have an isosceles trapezoid, and you connect the midpoints of the four sides of the isosceles trapezoid forming a quadrilateral, how do you prove that it's a rhombus in a 2 column proof?? Answered by Penny Nom.
	a to the power zero		1996-06-03
		From Beti: Why is a number to the power 0 equal to 1? Answered by Harley Weston.
	Prove that these two lines are parallel.		1996-05-29
		From Adam Piekarzewski: Using parallel line theorems and side angle side etc. in triangle acd a line is drawn from point b on ac and point i on ad. another triangle fliped vertically and joined at d is named fdh, a line is drawn from point e on fd and point g on fh. ab = fg, ai = fe, ac || fh prove that bi || eg /- -/ Answered by Harley Weston.
	How do you graph these inequalities?		1996-05-17
		From Robert: How do you graph the inequalities 5+gg, and g+h>6 on one coordinate plane? Answered by Harley Weston and Maxine Stinka.
	How do you graph these equations?		1996-04-30
		From David Gamble: How do you graph the equation x=3 on a x,y graph? Also how do you graph f(x)=-3x + 2 on the same graph? Answered by Harley Weston and Maxine Stinka.
	A coin problem		1996-04-16
		From Julie Hebert and Simon Hamel: How many weighings would you need to find out which pile is fraudulent? Answered by Penny Nom.
	An application of Pythagoras' theorem		1996-04-09
		From Mike: We'd like to know what practical applications there may be for the Pythagorean theorem. Answered by Penny Nom and Maxine Stinka.
	Area of an annulus		1996-04-04
		From Ryan Levering: What is the area of this annulus? Answered by Penny Nom.
	Area=Perimeter		1996-04-02
		From Jason Pelowski: When will the area and the perimeter of a right triangle be numerically equal? Answered by Penny Nom and Maxine Stinka.
	Square roots		1996-03-16
		From Terry King and John: We are just curious about how to manually calculate square roots. Answered by Harley Weston.
	The impossible problem		1996-03-15
		From Shaun Reynolds and Jacob Hiatt: How do you solve (the 6th root of x)+4=3? Answered by Penny Nom and Maxine Stinka.
	Cardano's method		1996-03-11
		From Mike Gorski: What is Cardano's method for finding the roots of a cubic equation? Answered by Harley Weston.
	Grade nine problem solving		1996-03-11
		From Azmat Hussain: Can math problems be actually fun and engaging? Answered by Diane Hanson.
	A trig identity		1996-03-11
		From Azmat Hussain: Is there an easier/another way to prove the trig identity cos(a+b) = cos(a)cos(b)-sin(a)sin(b)? Answered by Penny Nom.
	Pronunciation		1996-03-05
		From Todd Stienhauser: Is 123.4 pronounced "one hundred and twenty three and four tenths"or "one hundred twenty three and four tenths"? Answered by Penny Nom.
	Exponents		1996-02-25
		From Eric Cote: I want to know why the grade six math books tell you that the little number at the top right of another number (exponent) is called the power, but the grade seven and up books tell you it's called the exponent? Answered by Harley Weston.
	Algorithms for roots		1996-02-22
		From Charles Hewitt: I have seen an algorithm for finding the square root of numbers. Are there similar such algorithms for higher roots? Answered by Harley Weston.
	Prime numbers		1996-02-22
		From Charles Hewitt: I would apprecaite it if you could share with me any algorithm to determine whether a number is prime. Answered by Penny Nom.
	Queue length		1996-02-22
		From Frank Fronhofer II: How long is the toll booth queue? Answered by Harley Weston.
	e^(i*pi) = -1		1996-02-19
		From Matt Schneider: Why is e^(i*pi) = -1? Answered by Harley Weston.
	Pascal's Triangle		1996-02-19
		From Richard: Do you know of any resources that might help us make use of the numeric relationships in Pascal's triangle on a fairly simple basis? Answered by Denis Hanson.
	Neighbourhoods		1996-02-14
		From Robert: What are neighbourhoods? Answered by Harley Weston.
	Euclid's Pythagorean proof		1996-02-14
		From Sean: What is Euclid's proof of Pythagoras' theorem? Answered by Harley Weston.
	Stairs		1996-02-12
		From Marianne and Carrie: How many ways can you run up a flight of stairs? Answered by Denis Hanson.
	What is the variance of the difference of two binomials?		1996-02-08
		From Chris Johnson: My co-workers and I have come up with different estimates of the z-statistic, and are in particular disagreement over the calculation of Variance for this problem. I am trying to find out, with a five percent level of significance, whether the new form yields a higher rate of return than the old form. Any thoughts, comments, or solutions? Answered by Harley Weston.
	Converting to other bases		1996-02-06
		From Paul: Converting base 10 numbers to other bases Answered by Penny Nom.
	Number of factors		1996-01-30
		From Chrissy: What number has exactly 13 positive factors? Answered by Penny Nom.
	Trig identities		1995-11-30
		From Azmat: Why do we work on the two sides of a trig identity separately? Answered by Harley Weston.
	(-3)x(-2)		1995-10-25
		From Azmat: Why is (-3)x(-2) = 6? Answered by Herley Weston and Ed Giesbrecht.
	Complex numbers		1995-10-22
		From Jacquie: Why should we teach complex numbers in high school? Answered by Harley Weston.
	Magic Square		1995-10-20
		From Marianne and Carrie: How can an 8 by 8 square have the same area as a 5 by 13 rectangle? Answered by Denis Hanson.
	What is the golden section?		1995-09-17
		From Cindy: What is the golden section of a line? Answered by Denis Hanson.
	Solides d’Archimède		2014-04-29
		From Clémentine: Pourquoi une pyramide a base carrée n'est elle pas un polyèdre archimedien ? J'ai pourtant essayé d'en construire un avec tout ses cotés égaux et ça fonctionne ! Aidez moi je n'en dors plus la nuit ? :S Answered by Chris Fisher.
	deux wagons		2013-04-05
		From Cyril: Bonjour, je suis confronté à un problème dont je n'arrive pas à trouver la solution. Le voici: "Deux wagons de masses 30 tonnes et 60 tonnes entrent en collision sur une voie ferrée droite horizontale, ne déraillent pas et restent collés ensemble après le choc. Juste après la collision, ils roulent ensemble à 10 km/h vers le nord. Sachant que le wagon léger roulait à 20km/h vers le nord avant la collision, la vitesse du wagon lourd avant la collision = ?" Je pense qu'il faut employer la formule de la quantité de mouvement "p=mv" mais je ne sais pas comment m'y prendre... Merci d'avance pour votre aide! Cyril Biselx Answered by Claude Tardif.
	calcul de durée		2012-09-03
		From laila: un bus démarre de paris à 8h 45mn s'il fait 42h 20 mn de trajet entre paris et la ville suivante à quelle heure il arrivera à la ville suivante. est ce qu'il ya un shema pour calculer ou comment procéder. je sais qu'il faut additionner 8h 45 mn à 42h 20mn, mais comment on trouve le résultat rapidement. merci Answered by Claude Tardif.
	Les dérivées partielles		2012-05-16
		From Haddouche: Bonjour, Je vous demande de bien vouloir m'éclaircir comment on calcule les dérivées partielles généralement étudiées dans les modèles de la concurrence fiscale à titre d'exemple celui de Wildasin ""NASH EQUILIBRIA IN MODELS OF TAX COMPETITION "", dont j'ai essayé toutes les méthodes et aucune d'elle n'est arrivée à trouver le résultat des dérivées de ce dérnier papier, à cet effet, je vous serais reconnaissant de m'éclaicir la méthode afin de résoudre ce problème qui pour moi un vrai mistère à percer. Je vous remercie infiniment à l'avance. Et comptant sur votre compréhension, mes salutations les meilleures. HA Answered by Claude Tardif.
	Combien de bonds aura-t-il besoin		2012-04-10
		From zachary: Un lapin fait toujours un bond de 3m suivi d'un bond de 5m. S'il maintient ce rythme de combien de bonds aura-t-il besoin pour franchir une distance de 584m ?? Answered by Claude Tardif.
	un triangle		2011-11-07
		From Haelita: La corde élastique a une longueur de 60cm au repos . Quelle est la nouvelle longueur de la corde si on l'écarte de 11 cm en la tirant par son milieu ? Answered by Claude Tardif.
	Les calcules avec les heures		2011-09-09
		From johanna: bonjour je voudrais pouvoir expliquer a mon fils ces calcules avec les heures, mais franchement je n'y comprend rien, pouvez vous m'aider. voilà le premier calcul: 1h35min29s - 46min37s deuxiéme exercice: calculer la durée d'une emission télévisé qui débute à 20h40min et se termine à 22h17min. troisiéme exercie: je suis partie en vacances le 25 juillet. Mes vacances ont durées 2 semaines. Quel jours suis-je revenu? quatroéme exercice: je pars de st-pierre, je prend le bus. je veut arrivé à st-denis à 10h et demi. je sais que la durée du trajet st-pierre /st-denis est de 1h50min. a quel heure dois-je partir de st-pierre. Answered by Claude Tardif.
	Une sortie		2011-08-26
		From SANGES: un groupe d'amis souhaite organiser une sortie. si chacun donnait 14 euros, il manquerait 4 euro. Mais si chacun donnait 16 euros, il y aurait un excédent de 6 euro. combien y a-t-il d'amis dans le groupe ? Answered by Claude Tardif.
	La conjecture de Goldbach		2011-02-18
		From ahmedbenmoussa: montrez que tout nombre entier paire supérieur à 4 s'écrit somme de deux nombres premiers Answered by Claude Tardif.
	une écriture plus simple des expressions		2011-01-13
		From jessie: trouver une écriture plus simple des expressions suivantes sachant que : x + y = 3 et x - y =-2 A=x-1+y+2             B=x-1+y-2 C=x+1+y+2            C=x+1+y-2 Answered by Claude Tardif.
	(5+3)/2-3=		2010-12-10
		From chantal: (5+3)/2-3= Answered by Claude Tardif.
	Terminologie mathematique		2010-10-31
		From Adil: Bonjour , Pourriez-vous m'indiquer les titre et auteur d'un bon dictionnaire francais anglais de terminologie mathematique ? Auriez-vous egalement l'adresse d'un site web traduisant du francais a l'anglais les termes ert expressions mathematiques ? Merci par avance, Adil Answered by Pierre-Louis Gagnon.
	Un polynome de degré 3		2010-10-09
		From ait: comment determiner n polynome P de degré 3 verifiant pour tout reel x la relation p(x+1)-p(x)=x² Answered by Claude Tardif.
	Quel est le 6e nombre dans la serie suivante		2010-08-13
		From jeff: Quel est le 6e nombre dans la serie suivante: 1,2,6,42,1806,... Answered by Stephen La Rocque and Claude Tardif.
	une suite		2010-07-01
		From djodilune: Salut tout le monde ! J'ai un probleme de math dans un concours de Medecine , Le voilà : n £ N* on a : S = 1/[n(n+1)] + 1/[(n+1)(n+2)] + ... + 1/([2n(2n+1)] . reponse a : S= 1 - 1/n Reponse b : S= 1 - 1/(2n) Reponse C : S= 1 - 1/(n+1) Reponse D : S= (1/n) - (1/2n ) Reponse E : S= (1/n) - [1/(2n-1)]. Si vous pouvez me donner le reponse avec justification pour comprendre bien. Merci d'avance Answered by Claude Tardif.
	Mathilde aime la musique et les mathématique.		2010-04-19
		From Lucas: j'ai un problème pouvait vous m'aider a le résoudre:Mathilde aime la musique et les mathématique.Quand on lui demande combien de CD elle a elle répond "Je ne les ai pas comptés.quand je les groupe 5 par 5 ,il ne m'en reste pas.quand je les groupe 2 par2,il m'en reste 1.quand je les range 6 par 6,il m'en reste 5.je suis surque j'en moins que cinquante." Peux-tu trouver le nombre de CD de Mathilde? aider moi svp ps:je suis en 6ème donc faut pas que se soit trop compliqué Answered by Claude Tardif.
	l'orientation d'un plan dans l'espace		2010-03-22
		From gianno: comment calculer l'orientation d'un plan dans l'espace Answered by Claude Tardif.
	Division		2010-03-10
		From lucas: bonjour je suis eleve de 6 eme je bloque sur ce petit probleme Nat a fait une division,elle ecrit 4568=23*198,608+reste que vaut ce reste? merci d'avance lucas Answered by Claude Tardif.
	Résolution d'une équation		2010-02-25
		From sellin: Il faut que j'exprime x en fonction de m dans l'équation suivante et je n'y arrive pas: -3x + 1 = (m-1) / 2 * x + (2m + 3) / 5 Answered by Claude Tardif.
	Léo a programmé sa tortue		2010-02-15
		From Lucas: pouvez vous m'aidez a résoudre le problème géométrie suivant: Léo a programmé sa tortue en lui donnant les ordres suivant:execute 5 fois les instructions suivante: avance de 4 cm puis tourne a 72° a droite.Dessine le parcour de la tortue. La tortue est partie d'un point A , que lui dire pour qu'elle revinne a son point de départ? Merci d'avance Lucas Answered by Claude Tardif.
	Deux nombres consécutifs		2010-01-18
		From Janot: Bonjour comment peut on faire pour démontrer que si deux nombres sont consécutifs, leur produit et leur somme sont premiers entre eux Merci de me mettre sur la voie , j'ai échoué avec Bezout. Answered by Claude Tardif.
	Volume d'une sphere entre 4 autres spheres		2010-01-18
		From Bonfils: Bonjour, Je souhaiterais en fait calculer le rayon de la sphère max qui pourrait s'insérer entre 4 sphères de rayon connu. Merci par avance pour votre réponse. Sincères salutations Answered by Chris Fisher.
	soustraction		2010-01-14
		From LUCAS: comment faire l'operation suivant car je ne me souvient plus tres bien D'avance merci 4h44mn53s-2h52mn45s Answered by Pierre-Louis Gagnon et Claude Tardif.
	L'aire d'un hexagon, octagon etc		2010-01-07
		From danie: C'est quoi la formule pour l'aire d'un hexagon, octagon etc. est-ce que c'est Nombre de cotes x ((L'apothem x la mesure d'un cote tout divise par 2)??? Answered by Claude Tardif.
	triacontaèdre rhombique		2009-12-22
		From Paul: Je voudrais savoir si les quatre polyèdres suivants sont le même: P1:c'est le polyèdre convexe de centre O dont les sommets (62)sont les projetés (sur la sphère de centre O et de rayon 1,i.e U), des sommets(12), des milieux des arêtes(30),et des centres des faces(20) de l'icosaèdre de Platon (de centre O); P2::c'est le polyèdre convexe de centre O dont les sommets (62)sont les projetés (sur la sphère de centre O et de rayon 1,i.e U), des sommets(20), des milieux des arêtes(30),et des centres des faces(12) du dodécaèdre de Platon (de centre O); P3:c'est le polyèdre convexe de centre O dont les sommets (62)sont les projetés sur U des sommets du disdyakis-triacontaèdre (dual polaire du grand rhombicosidodécaèdre)(de centre O); P4:c'est le polyèdre convexe de centre O dont les sommets (62)sont les projetés sur U des sommets (32) et des centres des faces (30) du triacontaèdre rhombique (dual polaire de l'icosidodécaèdre) (de centre O). Merci pour la réponse, et bonnes fêtes. Paul Answered by Robert Dawson and Chris Fisher.
	Les polyèdres		2009-11-12
		From Paul: Parmi tous les polyèdres dont les sommets sont sur une sphère et dont les faces sont isométriques (pas nécessairement régulières, ni nécessairement triangulaires), "(2,3,5)" (voir définition ci-après) est-il celui qui présente le plus grand rapport entre les rayons des sphères inscrite et circonscrite? "(2,3,5)" désigne le polyèdre (de centre O) dont les faces sont des triangles isométriques tel que: si ABC est une face, les mesures des dièdres d'arêtes OA, OB, OC sont pi/2, pi/3 et pi/5. Merci pour ce site. Paul Answered by Robert Dawson and Claude Tardif.
	Le plus grand commun diviseur		2009-11-11
		From Katie: Question: Pendant mon cours de MAT 1300, mon enseignant m'a posé la question suivante: (a, b) = 12 (a², b) = 24 (b, 72) = ? Pouvez-vous m'aider s'il-vous-plaît? Answered by Claude Tardif.
	Une piscine		2009-11-04
		From kemayou: Dans un de ces problèmes,ma fille se trouve face à cette question,et je ne parviens pas à l'aider,pourriez-vous nous donner un petit coup de pouce? Voici l'énoncé:Un jardin a 22m de long et 8m de large.Au centre du jardin,on a fait construire une piscine dont le périmètre est de 44m.La surface restante est couverte de gazon. La question est :exprimer en fonction de x la longueur de cette piscine. Dans l'attente de votre réponse,recevez nos salutations distinguées. Merci.Mme kemayou Answered by Claude Tardif.
	Le volume d'une boule		2009-10-22
		From ve.lu.ch: Pour calculer le volume d'une boule, il faut utiliser la formule : 4/3 x Pi x R au cube Pourquoi 4/3 ? Merci d'avance Answered by Pierre-Louis Gagnon et Claude Tardif.
	Un triangle isocèle		2009-10-08
		From lauwick: ABC un triangle isocèle en A de périmètre 16 cm. De plus son aire est égale au quart de l'aire du carré construit sur sa base bc. Quelles sont les longueurs des cotés de ce trangle? Merci Answered by Claude Tardif.
	Polyèdres		2009-10-07
		From DEPASSE: Si un polyèdre est inscriptible et circonscriptible, et si ses faces sont isométriques(non nécessairement polygones réguliers) , le dièdre entre deux quelconques de ses faces adjacentes est il toujours le même ? Si non, un exemple? Answered by Claude Tardif.
	Trigonometrie		2009-08-07
		From Michaël: Bonjour, Je cherche a vérifié cette relation de trigo, Tan^2x = Sin^2x +Sin^2x*Tan^2x. après de nombreux essais, j'arrive à ce résultat: Tan^2= 1-cos^2x + 1-cos^2x*(sin^2x/cos^2x) Merci de votre aide Answered by Claude Tardif.
	Le réservoir		2009-04-09
		From Myrianne: Le réservoir d'essence d'une petite voiture peut contenir 50 litres. En sachant que 1 dm3 équivaut à litre, donne les dimensions de deux prismes différents représentant ce réservoir. Answered by Claude Tardif.
	Preuve du volume d'une boule		2009-04-06
		From Geneviève: J'aimerais avoir l'explication du volume de la boule, qui est (4pi R au cube) divisé par 3. J'aimerais savoir le pourquoi de l'équation, la preuve de celle-ci. Merci! Answered by Pierre-Louis Gagnon.
	Une multiplication		2009-04-03
		From josee: 24/6x5+40-10= le x est une multiplication et il n'y as pas de parenthèses. Merci Josée Answered by Antoine Letarte and Claude Tardif.
	Algebre		2009-03-04
		From Jonnathan: Pour entrer sur le site d'une exposition, il en coute 41$ pour 2 enfants et 2 adultes mais 37.50$ pour 3 enfants et un adulte. Quel est le prix de la rentree pour l'enfant et quel est le prix de la rentree pour l'adulte? il faut utiliser la methode de comparaison ou de substitution Answered by Claude Tardif.
	Calculs de minutes en heures		2009-02-23
		From Denis: Je suis en train de suivre un cours en navigation maritime et je dois changer souvent des minutes en heures. ex: 495 minutes = ?h?? Je désire avoir le cheminement le plus simple a faire pour ce type de calcul. Je ne travail pas avec excell. Je veux une formule a faire seulement avec une calculatrice élémentaire. Merci pour votre aide, j'apprécie beaucoup votre coup de main. Denis. Answered by Claude Tardif.
	Hauteur d'un tétraèdre		2009-02-23
		From Sébastien: Bonjour; J'ai trouvé un exercice de maths sur internet pour m'entraîner, j'ai bientôt fini, il me manque juste la dernière question à laquelle je bloque. Voici l'énoncé : Sur les arêttes d'un cube, on marque les points I, J et K tels que Ai=AJ=AK=x, où x est un réel donné strictement positif et strictement inférieur à la longueur a de l'arête du cube. La question 1) disait que le triangle IJK est équilatéral et que son aire est de( x² racine de 2)/2. La question 2) disait que AIJK est un tétraèdre et que son volume est de (x au cube) /6. Et la question où je bloque : 3) La perpendiculaire menée par A au plus (IJK) coupe ce plan en H. Calculer AH en fonction de x. Merci de votre aide! Bonne journée. Answered by Claude Tardif.
	Un système de plusieurs équations et plusieurs inconnues		2009-01-22
		From Cédrick: J'ai un problème écrit à résoudre est-ce que vous pouvez m'aider ? Le premier est le tiers de la somme des deux autres. La somme du premier et du deuxième est 13. Le produit du deuxième et du troisième est 56. Réponse: Le premier nombre est___________________ Le deuxième nombre est _________________ Le troisième nombre est _________________ Answered by Pierre-Louis Gagnon, Antoine Letarte at Claude Tardif.
	Un volume d'une capacité minimal		2009-01-05
		From Pauline: je doit faire un volume d'une capacité minimal de 2500 cm 3 en quell matiere que ce soit * un prisme a base pentagonale non réguliere * une sphere * stella octangula Answered by Pierre-Louis Gagnon.
	La longueur de la corde		2008-12-24
		From Lucile: Voici l'énoncé : On appelle (C) un cercle de centre O et de rayon 6cm. A et B sont deux points du cercle (C) tels que AOB = 50° Calculer la longueur de la corde [AB] (arrondi au millimètre). On justifiera soigneusement toutes les étapes. Cela fait déja 1 semaine que je trouve pas la réponse a cet énoncé . Pouvez vous m'aider ? Merci d'avance . Answered by Pierre-Louis Gagnon.
	Probleme de trigonométrie		2008-12-06
		From Maryne: On donne AB=15cm, AC=30,5cm et A=35°. Calcule BC à 0;01cm près. Calcule B et C à 0,01° près. Calcule l'aire du triangle à 0,01cm² près. Sachant que le triangle n'est pas rectangle. Merci Answered by Pierre-Louis Gagnon.
	Fonctions dérivées		2008-11-28
		From Genevois: Bonjour ! Je dois trouvé la dérivée en 2 de la fonction 40-5x². Or, je sais comment faire et je connais la réponse mais j'ai beau refaire et refaire le calcul, mon résultat n'est jamais le meme que celui du corrigé, j'ai donc un probleme de calcul, pourriez vous donc me donner le calcul détaillé s'il vous plait ? Merci d'avance ! Answered by Pierre-Louis Gagnon.
	Une série géométrique		2008-11-23
		From anass: je vx savoire est ce kil existe la somme de (1/n^x) avec n variant de 0 jusk à infini nota: lorsk x=1et 2 la somme reste tjrs facile mé lorsquil depasse 3 c difficile et merci Answered by Pierre-Louis Gagnon.
	La somme de son carré et de son cube		2008-11-05
		From halima: Trouvez un nombre entier tel que la somme de son carré et de son cube soit égale à 9 fois le nombre entier suivant. Answered by Pierre-Louis Gagnon.
	J'ai l'équation X^n=Y Je cherche à sortir n.		2008-11-05
		From Jean-Philippe: Bonjour. J'ai l'équation X^n=Y Je cherche à sortir n. Existe-t-il une équation donnant n=f(X,Y) ? Answered by Pierre-Louis Gagnon et Émile Létourneau.
	calcul heures et minutes		2008-06-08
		From cadare: je n'arrive pas à comprendre et resoudre mes problèmes d'heures et de minutes,ex parti à 22h30, j'arrive à 7h15 quelle est la durée du trajet Answered by Claude Tardif.
	Pourcentage		2008-06-02
		From ferdjoukh: un article passe de 12 euros à 10 euros. quel est le pourcentage de réduction? et quelle est l'opération à faire pour obtenir le résultat? merci Answered by Antoine Letarte.
	Le volume du tas		2008-05-28
		From ribot: je cherche la formule mathematique du volume d un tas de cailloux formule employée dans le bâtiment Answered by Thierry Moisan.
	Un tetraèdre régulier		2008-05-05
		From delabroye: La figure ci-contre est un tetraèdre régulier : AB = AC = BC = AD = 6cm 1) Représente un patron de ce tetraèdre 2) Calcule le volume de ce tétraèdre Answered by Thierry Moisan.
	méthode pour trouver l'air d'un carré		2008-04-08
		From Mélodie: je doit trouver au moins 4 manieres différentes de calculer l'air d'un carré. j'en ai déja trouvée 2 mais il m'en faut le plus possible... 1. longueur x largeur 2. division en triangles, puis air des triangles et multipler par l'air des triangles Answered by Thierry Moisan.
	Énigme		2008-04-06
		From Frédérique: Tu es dans une pièce ou il y a 3 interrupteurs reliés a 3 lumières dans une autre pièce que tu ne vois pas.Comment fais-tu pour savoir a quelle lumière chacun des interrupteurs est relié si tu ne peux aller voir dans l'autre pièce qu'une seule fois!Merci a l'avance!!! Answered by Claude Tardif.
	Combien d'éleves fréquentent cette école?		2008-04-04
		From Jeff: Une ecole compte sept fois plus d'éleve que d'enseignants et enseignantes .De plus , le nombre de membres du personnel non enseignant correspond a la moitié du nombre d'enseignats et enseignantes . Si l'on tient compte de l'ensemble des éleves , du personnel enseignant et du personnel non enseignante , on dénombre 714 personnes . Combien d'éleves fréquentent cette école? Answered by Antoine Letarte.
	La dérivée de f(x)=ln[(1/16)(-x^2+6x+16)]		2008-03-31
		From Mathilde: Je viens de reprendre mes études et j'ai quelques lacunes, pourriez - vous m'aider à trouver la dérivée de cette fonction. Comme ça je pourrais vérifier si mon résultats est juste avant de faire l'étude de fonction. f(x)=ln[(1/16)(-x²+6x+16)] Merci Mathilde Answered by Maxime Fortier Bourque et Pierre-Louis Gagnon.
	Le terme suivants		2008-03-30
		From jacques: voici 2 suites. Explique la logique qui permet de passer d'un terme a l'autre dans chacune des suites et trouve le terme suivants. 1)douze,5,trente,6,neuf,4,seize,... no.2) 26,vx,18,dt,36,tx,51,... Answered by Maxime Fortier Bourque.
	Qui sommes nous?		2008-03-28
		From Cédrick: Nous sommes deux nombres inférieurs à 40. Le nombre 11 est un de nos facteurs. Le produit de nos chiffres est un facteur de 8. Si nous changeons nos chiffres de place nos noms de changent pas. Qui sommes nous? Answered by Maxime Fortier Bourque.
	la capcite en metre cube de ma remorque		2008-03-22
		From pages: je voudrai connaitre la capcite en metre cube de ma remorque les dimensions font 124-95 -34 merci Answered by Pierre-Louis Gagnon.
	Un bénéfice de 5%		2008-03-11
		From mahiques: Un propriétaire decide de vendre deux parcelles de terrains pour un montant total de 141750 F. Il fait un bénéfice de 15% sur la première et une perte de 10% sur la deuxième. L'ensemble de la transaction lui a rapporté un bénéfice de 5%.combien a-t-il vendu chacune des parcelles ? Answered by Pierre-Louis Gagnon.
	Logarithmique et semi logarithmique		2008-03-08
		From azaar: Je veux savoir comment passer d'un échelle linière à l'échelle logarithmique ou semi logarithmique ? Answered by Lierre-Louis Gagnon.
	l'armature d'un prisme		2008-03-01
		From dufetre: a l'aide d'une tige de 63cm on desire construire l'armature d'un prisme dont la base est un triangle equilateral et dont la hauteur mesure 3cm de plus que la la longueur du cote du triangle. Soit x la longueur du cote du triangle.exprimer en fonction de x la hauteur de ce prisme exprimer en fonction de x la longueur totale des aretes Quelle sera la longueur du cote du triangle. merci Answered by Maxime Fortier Bourque et Thierry Moisan.
	Combien y a t il d amis dans le groupe		2008-02-25
		From vaucher: un groupe d amis souhaite organiser une sortie si chacun donnait 14 € il manquerait 4 € mais si chacun donnait 16€ il y aurait un excedent de 6 € combien y a t il d amis dans le groupe Answered by Maxime Fortier Bourque.
	exercice de trigonométrie		2008-02-19
		From Maxime: Montrer que dans un triangle quelconque le produit des cosinus des angles cosA*cosB*cosC est inférieur ou égal à 1/8. Answered by Pierre-Louis Gagnon et Thierry Moisan.
	moyenne statistique		2008-02-16
		From jossan: Annexe nombre d'habitants Nombre d'agglomération centre de classe 3 ; 3.5 11 3.25 3.5 ; 4 16 3.75 4 ; 4.5 7 4.25 4.5 ; 5 10 4.75 5 ; 6 12 5.5 6 ; 8 10 7 8 ; 10 9 9 10 ; 15 13 12.5 15 ; 20 6 17.5 20 ; 32 5 26 Total 99 question : compléter la deuxième et troisième colonne (c'est fait) puis en utilisant la valeur centrale des classes calculer le nombre moyen d'habitants . arrondir la valeur à l'unité. on peut utiliser uniquement les fonctions statistiques de la calculatrice et écrire directement la valeur de N Answered by Pierre-Louis Gagnon et Antoine Letarte.
	La valeur absolue		2008-02-09
		From Elodie: que signifie la notation x entre 2 traits verticaux? Answered by Claude Tardif.
	calcul des hh,mn,sec		2008-01-19
		From gillot: bonjour, mon fils à des additions et soustractions d'horaire et je n'arrive pas à trouver la règle pour lui espliquer comment il faut faire il y a t il une formule pour les additions et soustractions merci par avance pour vos réponses Answered by Claude Tardif.
	Je voulais savoir d'où provient le signe # ?!		2008-01-17
		From Dimitri: Je voulais savoir d'où provient le signe # ?! On l'appelle diez, sur les téléphones surtout, mais j'aimerai savoir plus précisément à quoi sert ce signe (autre que sur nos appareils) ! Et pourquoi, en anglais, s'il est placé avant un chiffre, on dit 'number' (par exemple #1, 'Number one'). Son origine m'interesse tout autant que son utilité ! Answered by Claude Tardif.
	Arithmétique modulaire		2008-01-10
		From hausknecht: ma grand mère a entre 60 et 80 ans.il y a un an son âge était un multiple de 3.dans deux ans son âge sera un multiple de 2,de 3 et de 9.cette année , c'est un multiple de 5.quel est l'âge de ma grand mère? Answered by Claude Tardif.
	Progression arithmétique		2008-01-08
		From parrot: Bonjour je suis en 6ème et j'ai besoin d'aide pour un problème de math. Donc voila mon problème : Un renard a mangé 100 grains de raisins pendant une periode de 5 jours. Chaque jour, il a mangé six grains le plus que le jour précédent. Quel est le nombre de grains mangés le premier jour ? Answered by Claude Tardif.
	racine carre de 9		2008-01-01
		From hichem: racine carre de 9 Answered by Claude Tardif.
	800 poules pondent 800 oeufs en 8 jours		2007-12-17
		From LINDA: 800 POULES EN 8 JOURS PONDENT 800 OEUFS, COMBIEN 400 POULES VONT-ELLES PONDENT D'OEUFS EN 4 JOURS? Answered by Claude Tardif.
	Système à deux équations		2007-12-11
		From Fabrice: un rectangle a 130 m pour périmetre. si on diminue sa longueur de 1 m et on augmente sa largeur de 1 m, l'aire augmentera de 14m². trouver les deux dimentions du rectangle. (on trouvera, au préalable, la difference des deux dimensions) Answered by Claude Tardif.
	Une sphere		2007-12-03
		From karine: voici ce que je dois trouver ; j'aiune boule disco mesurant 48'' de diametre je veux savoir combien de petit miroir il y a sur cette boule si les petits miroires on 1'' carré ? Answered by Claude Tardif.
	n(n+1) est un nombre pair		2007-12-02
		From Christel: Bonjour. J'aimerai savoir comment l'on peut démontrer que n(n+1) est un nombre pair. Si vous avez une méthode...Merci d'avance Answered by Claude Tardif.
	A=B+C+D+F+G+H+J		2007-11-27
		From Boubendir: voila ma question et comme savoir les nombres additioné en etulisant le resultat A=B+C+D+F+G+H+J au debut ons a les B,C,D,F,G,H,J on connaissent leur valeur comment retrouver valeur on etulisant leur resultat Answered by Claude Tardif.
	F=4a-3c+6b		2007-11-22
		From olive: comment calcule ton ? F=4a-3c+6b mon fils et en 4ème et je suis dépassée, je ne peut pas l'aider merci de le faire à ma place. Answered by Claude Tardif.
	La somme de deux fonctions		2007-11-19
		From maud: Consigne : Ecrire la fonction f comme somme de deux fonctions u et v définies sur I. Donner le sens de variation de u et de v sur I. En déduire le sens de variation de la fonction f sur l'intervalle I indiqué. f(x)=-2x+(1sur x) I=]0;+infini[ Correction : Sens de variation de f sur I=]0;+infini[ On a f(x)=u(x) + v(x), avec {u(x) = -2x et v(x) = 1sur x La fonction u est strictement décroissante sur R, donc sur I ( droite avec coefficient directeur -2 négatif). La fonction v qui est la fonction inverse est stricyement décroissante sur [0;+infini[. Donc, la fonction f = u+v est strictement décroissante sur [0;+infini[. Ma question : Pourquoi la fonction v et la fonction f ne sont pas définies sur le même intervalle que la fonction u c'est-à-dire sur l'intervalle I indiqué ? Answered by Claude Tardif.
	nombre d'or		2007-11-12
		From Léo: On suppose que le rapport a+b/a est égal au nombre d'or (1+racine carrée de 5/é) a) Calculer (a+b) au carré et a+(a+b) en fonction de a. Je n'y arrive pas. Pouvez-vous m'aider? merci Answered by Claude Tardif.
	La somme de deux entiers naturels est égale à 83.		2007-11-06
		From abraham: La somme de deux entiers naturels est égale à 83. Si on divise le plus grand par le plus petit , on obtient 4 comme quotient et 17 comme reste. Quels sont les deux nombres ? Justifier clairement la réponse. Merci de me répondre au plus vite. Answered by Claude Tardif.
	Le symbole ∈ epsilon		2007-10-10
		From Cora: Je veux aider ma fille avec ses devoirs. C'est quoi le symbole qui semble un E, mais c'est un demi-circle? ie:X ∈ N Answered by Claude Tardif.
	La somme des «N» premiers nombres naturels impairs		2007-10-09
		From Dominique: Quelle expression algebrique représente la somme des «N» premiers nombres naturels impairs ? Answered by Claude Tardif.
	les données sont inconsistantes		2007-10-03
		From Mikee: Bonjour, Je me casse la tete depuis ce matin et la je donne ma langue au chat. Je n'arrive pas a resoudre ce probleme. J'ai 30 agents qui appellent dans la journee et realisent 322 questionnaires (long+court) telephonique avec une duree moyenne de conversation 294 secondes. dans ces 322 qestionnaires : -ils realisent 313 questionnaires Long avec une duree moyenne de 317 secondes. -ils realisent 9 questionnaires Court avec une duree moyenne X. je cherche X. ((Interviews réalisées*Durée moyenne de conversation)-(Interviews réalisées avec la question Q2*Durée moyenne de conversation avec la question Q2))/(Interviews réalisées-Interviews réalisées avec question Q2)=Durée moyenne de conversation sans la question Q2 Q2=questionnaire Long Answered by Claude Tardif.
	un jardinier plantent 10 arbres		2007-09-30
		From yannick: un jardinier plantent 10 arbres.il a reussi a les disposer en formant 5 ligne de 4 arbres. retrouver une disposition possible Answered by Claude Tardif.
	Quel est ce nombre		2007-09-30
		From fred: Un groupe de 7 enfants vient de recevoir une grosse quantité de billes. ils font le partage : toutes les billes sont distribuées et ils en ont chacun le même nombre. le nombre total de billes s'écrit avec les mêmes chiffres que 1991. Quel est ce nombre Answered by Claude Tardif.
	pente nulle		2007-08-31
		From stephanie: si la pente dune droite est nulle alors cette droite est quoi ??? Answered by Claude Tardif.
	Exemples d'équations a résoudre		2007-08-17
		From Stéphanie: j'aimerais connaitre les terme pour désigner pour les chiffres dans l'algèbre et pouvoir avoir quelques exemples d'équations a résoudre!! Answered by Claude Tardif.
	Je suis le plus petit entier de 3 chiffres. Qui suis-je?		2007-07-18
		From Auerhaan: De quel chiffre parle-t-on? Je suis le plus petit entier de 3 chiffres Qui suis-je? Le cahier de vacances donne comme solution : 120, ce qui me parrais très étrange !) Merci d'avance pour votre réponse..! Answered by Claude Tardif.
	cos^3x+sin^3x=1		2007-06-07
		From sannier: bonjour je bloque sur l'equation: cos^3x+sin^3x=1 j'ai essayé toute les formules de trigonometrie je n'y arrive pas.connaissez vous un moyen de resoudre cette equation ou de m'orienter? Answered by Claude Tardif.
	Deux terrains		2007-06-04
		From Aurelie: Deux terrains, un rectangulaire et l'autre carré, ont la même superficie. Si tu sais que la longueur du terrain rectangulaire mesure 40m et que le carré mesure 20m de côté, détermine la largeur du terrain rectangulaire. Answered by Claude Tardiff.
	Combien d'heures et de minutes		2007-05-30
		From masson: pouvez vous m'aider pour resoudre ce probleme car je suis perdue combien d'heures et de minutes dormez vous si vous vous couchez a 22h15 et si vous vous levez a 6h57? car en suivant le raisonnement de la soustraction d'heure je trouve 15h12 et je trouve cela pas logique merci d'avance de votre aide Answered by Claude Tardif.
	Combien vais je avoir de surface ?		2007-05-22
		From Maëlle: J'ai 5m3 de terre et veux en mettre 5 cm partout pour faire un terrain de jeux. Combien vais je avoir de surface ? Answered by Claude Tardif.
	Je veux convertir le m3 en kg		2007-05-14
		From Abdellah: je veux convertir le m3 en kg Answered by Claude Tardif.
	Dénombrement		2007-05-11
		From Cosse: de combien de façons peut-on faire 6 poules de 5 équipes avec 30 équipes? ou combien de partitions en 6 ensembles de 5 éléments dans un ensemble de 30 ? et aussi pourquoi ? Answered by Claude Tardif.
	Mesure/volume		2007-05-09
		From Ashley: Calcule le volume des 2 contenants et quels est le plus grands. Answered by Claude Tardif.
	Le pourcentage en +ou en- que représent la diférence de 2 nombres		2007-04-29
		From Jean: pouvez vous me donner la formule pour trouver le pourcentage en +ou en- que représent la diférence de 2 nombres ex: 8594 et 7634 Answered by Claude Tardif.
	proposition d'une fonction		2007-04-10
		From Benoit: Proposez une fonction f(x,y) dont l'ensemble de niveau c=0 est {(x,y) : x = 0} U {(x,y) : x*2+y*2=1} Je remarque l'équation d'un cercle centré à (0,0) et de rayon 1 ainsi que la droite x=0 mais ça ne clique pas. Merci de m'aider. Answered by Claude Tardif.
	Illusion géométrique		2007-04-04
		From Dominique: Je n'arrive pas expliquer la modofocation de surface. Answered by Claude Tardif.
	Le perimetre d un cercle		2007-03-15
		From Martins: Comment calculer le perimetre d un cercle sachant que le diametre et de 25 de plus que le perimetre Answered by Claude Tardif.
	nombre entier		2007-03-07
		From ROUILLARD: Quel est le plus grand entier inférieur au quotient de 200/9 ? Merci de votre réponse. Je pense à 19. Est-ce exact ? Answered by Claude Tardif.
	Dérivée logarithmique		2007-03-04
		From Albert: Déterminer la dérivée première des fonctions logarithmiques suivantes : 1) f (x) = x exposant x 2) f (x) = x exposant e exposant 2x Answered by Claude Tardif.
	Qui suis-je?		2007-02-28
		From un parent: bonjour, le problème est le suivant : Qui suis-je? Mon tiers augmenté de mes deux cinquième est égal à la moitié de mon triple Serez t'il possible d'avoir la solution à ce problème et que je puisse y comprendre un peu quelque chose quand même Je vous remercie d'avance et espère bientôt vous lire Answered by Claude Tardif.
	algèbre et fractions		2007-02-05
		From marion: Une certaine somme était inscrite sur un livret de caisse d'épargne au 1er janvier. Le 1er mars, on retire le tiers de ce qui était placé au 1er janvier. Le 1er juin, on retire le quart de ce qui était placé au 1er janvier. Il reste sur ce livret une somme égale à 1/7 des sommes retirées plus 1 600 Quel était le montant du livret d'épargne au 1er janvier? Answered by Claude Tardif.
	exposant 0		2007-01-25
		From Judith: Je suis stagiaire dans une classe de sixième année et j'aimerais pouvoir expliquer à mes élèves pourquoi tous les nombres exposant 0 donne 1 comme réponse. ( 10 exposant zéro = 1) Merci! Answered by Claude Tardif.
	il y a deux contenant		2007-01-23
		From Eric: il y a deux contenant un de 3 litre et un de 5 litre les deux sont vide comment en les remplisant on peux obtenire 4 litre Answered by Claude Tardif.
	Le produit des fractions		2007-01-23
		From Jasmine: Au mois de mars, le poids de la brebis augmente d'un huitième. Au mois d'avril, son poids augmente d'un neuvième, au mois de juin d'un onzième. Par quelle fraction faut-il multiplier son ancien poids pour obtenir son nouveau poids? Answered by Claude Tardif.
	boulier français		2007-01-19
		From Stéphanie: Je prépare une exposition sur le centième anniversaire du vieux couvent de Château-Richer dans la province du Québec qui s'ouvrira en mai 2007. Dans ce couvent les soeurs de la Congréagation du Perpétuel Secours ont enseigné pendant de nombreuses années. Pour mettre en valeur, le site et l'exposition, nous souhaitons mettre les visiteurs à l'épreuve dans l'ambiance d'une classe d'antan (début 20ème siècle) avec, entre autres, les bouliers français que nous possédons et leur faire faire des exercices de mathématiques avec. Malheureusement, nous ne savons pas comment faire les quatre opérations de base (addition, soustraction, multiplication et division) avec. Pouvez-vous nous l'expliquer de façon détaillé, s'il vous plaît? Answered by Claude Tardif.
	Horaire à créer		2007-01-18
		From Suzette: Je ne sais quel logiciel utiliser pour effectuer mon travail.Quelle science peut résoudre mon problème? J'ai 16 personnes qui effectueront 5 tâches différentes sur une période de 11demi- journées. Chaque tâche est accomplie par 3 personnes èa la fois par demi-journée. sauf la 5e tâche qui sera accomplie par 4 personnes. Je dois distribuer le travail à chacune des 16 personnes pour chaque demi-journée afin que toutes aient accompli les 5 tâches. Dites-moi comment m'y prendre, svp. Et si j'ai 17 personnes, j'aurai 2 groupes de 4 personnes et 3 de 3 personnes Answered by Claude Tardif.
	Multiplier et soustraire des nombres négatifs		2007-01-11
		From Sylvie: Voici trois nombres entiers: (-5), (-3) et (-4). On retranche le troisieme au produit des deux premiers, ecris la situation et donne le resultat. Answered by Claude Tardif.
	exercices corrigés		2007-01-09
		From Zribi: si je peut avoir des exercice corrigé Answered by Claude Tardif.
	Des grains de blé		2007-01-06
		From Renaud: Remplir un échiquier avec des grains de blé de la façon suivante un grain dans la 1ère case, deux grains dans la 2ème case, ainsi de suite en doublant jusqu'à la 64e case Combien de grains de blé il y a dans la 64e case? Answered by Claude Tardif.
	45 000 litres d'eau a 15 degres		2006-12-21
		From Troussiere: j'ai 45 000 litres d'eau a 15 degres combien de litres d'eau a 50 degres doit on rajouter pour obtenir une eau a 25 degres? Answered by Claude Tardif.
	sup {sin n, n est un entier }		2006-12-17
		From Madi: sup {sin n, n est un entier } Answered by Claude Tardif.
	l'intérêt		2006-12-06
		From Frédéric: Bonjour, je me permet de vous envoyer un "petit" problème mathématique car je suis très mauvais même pour de très simples opérations comme celle qui va suivre!(lol). Si vous pouviez m'aider cela m'éviterai beaucoup de recherches inutiles. Voici le problème : une personne a placé 117180 en banque et cette somme lui rapporte tous les trimestres 936 d'intéret. Premièrement, peut on connaître le taux d'intéret ? Et deuxièmement, combien lui rapporterai, en intéret, la somme de 97180 ? Merci d'avance pour votre aide. Answered by Claude Tardif.
	Origine du signe racine carré		2006-11-30
		From Kévin: Je suis simplement un élève de 3eme très curieux et j'aimerais savoir d'où vien le signe de la racine carré (l'espece de V) c'est une question toute bete mais ma prof de math ne peu me répondre le pouvez vous? Answered by Claude Tardif.
	volume d'un cône		2006-11-29
		From Emmanuel: On peut diviser un cube en 3 pyramides et ainsi en déduire le volume d'une pyramide. Mais comment peut-on déduire le volume d'un cône de celui d'un cylindre? Comment visualise-t-on la division d'un cylindre en trois? Answered by Claude Tardif.
	Quel est ce nombre?		2006-11-28
		From Dourlent: je multiplie un nombre par 10 et il augmente de135. Quel est ce nombre? Answered by Claude Tardif.
	addition et soustraction des heures, minutes, secondes		2006-11-22
		From Halnais: 13 h. 25 mn + 18 h. 06 mn 23 h. 31 mn + 19 h. 33 mn je ne me souviens plus très bien de ces opérations, faut-il additioner les heures à part puis les minutes, etc. pour les heures je crois qu'il ne faut pas dépasser 24 h. Pourriez-vous m'aider, et me donner le résultat, merci infiniment. Answered by Claude Tardif.
	les fraction		2006-11-07
		From Coullet: béreger boit les 3/5 d'une bouteille de 3/4 de litre jennifer boit les 4/5 d'une bouteille de 1/2 litre diego boit les 2/5 d'une bouteille de 1 litre, puis le quart de ce qui lui reste Answered by Claude Tardif.
	la somme des aires des deux dommaines		2006-11-06
		From Nina: Une ficelle de longeur L = 1m est coupée en deux morceaux. Avec l'un des morceaux, de longeur x, on forme un carré, et avec l'autre un cercle. A quel endroit doit on couper la ficelle pour que la somme des aires des deux dommaines obtenus soit minimale? Answered by Claude Tardif.
	équations avec les ages		2006-11-06
		From Ruffin: Sébastien dit a Aurélie: vous avez 36 ans et j'ai deux 2 fois l'âge que vous aviez quand j'avais votre âge. Quel âge a Sébastien? Answered by Claude Tardif.
	Les cinq ligner de chiffre		2006-11-02
		From Alex: comment faire pour trouver les cinq ligner de chiffre apres les avoir observer les sept premiere 1 11 21 1112 3112 211213 312213 - - - - - Answered by Claude Tardif.
	Des mots aux équations		2006-11-02
		From Julie: La différence de deux nombres, x et y est de 28. Le nombre y correspond aux huit neuvi�mes du nombre x. Trouvez ces deux nombres. Answered by Claude Tardif.
	Taux à déterminer		2006-11-01
		From Barrault: Une certaine année,un article augmente d' un certain taux "t" au premier semestre puis d' un taux triple du premier au second semestre, sachant que l' augmenation globale sur l' année est 66.75%; uels sont les taux pour chacun des deux semestres de l' année? Answered by Claude Tardif.
	Maximiser l'aire d'un triangle isocèle		2006-10-31
		From Flav: ABC est un triangle isocèle en A tel que AB= 1 pour quelles valeurs de BC, l'aire de ce triangle est-elle maximale? Answered by Claude Tardif.
	Un carré ABCD		2006-10-31
		From Barrault: Dans un carré ABCD de coté a , avec I le milieu du cote AB je cherche a exprimer CI et CA en fonction de a en demontrant que les vecteur CA+CB=2CI comment faire? Answered by Claude Tardif.
	logarithme		2006-10-24
		From Julie: Loga(x^2-4) - loga(x-2) Answered by Claude Tardif.
	Avec les chiffres 1,5,6,7, vous devez arriver a un total de 21		2006-09-28
		From Danny: J'ai un problème qui est le suivant: Avec les chiffres 1,5,6,7, vous devez arriver a un total de 21 en les utilisant qu'une seule fois et en utilisant la multiplication, l'addition, la division et la soustraction... Answered by Claude Tardif.
	le prix de départ		2006-09-10
		From un élève: Une jupe coûte 36 euros après une démarque de 20% quel est le prix de départ moi j'ai trouvé 45 euros mais je n'ai pas la formule de calcul exacte Answered by Claude Tardif.
	l'explication de 1 - 1,1 exposant -5		2006-08-12
		From Karin: Ma question est l'explication de 1 - 1,1 exposant -5 Answered by Claude Tardif.
	Combien a t-il rapporté dans une journée ?		2006-06-21
		From Madame Moro: On lui donne un prix au km soit 1630 €/km, Marc a réalisé 211 m dans la journée, Combien a t-il rapporté dans une journée ? Answered by Claude Tardif.
	Quel serait le cout total de production de 500 entrees		2006-06-10
		From Suzanne: Chaque operateur traite des donnees pendant 7 heures 1/2 par jour, et peut s'acquitter d'une demande en 3 heures et 3/4. Combien d'operateurs faudra-t-il pour traiter 50 demandes en 1 jour. Vous etes surveillant a l'entree des donnees. Pour atteindre vos objectifs vous engagez temporairement 2 commis a un salaire de 10$ et a raison de 8 heures par jour. Si chaque personne peut produire 50 entrees par jour, quel serait le cout total de production de 500 entrees. Answered by Claude Tardif.
	Un commis temporaire reclame 1200$		2006-06-10
		From Suzanne: Un commis temporaire reclame 1200$ pour 2 semaines de travail (5 jrs semaine) a raison de 15$ de l'heure. Au cours de ces 2 semaines, le commis a inclus par erreur dans ses heures de travail la periode de 30 min pour la pause de diner. Quel est le montant a payer...J'ai essaye de trouver une reponse et je n'y arrive pas. Answered by Claude Tardif.
	Dernier théorème de Fermat		2006-06-06
		From Jean-Claude: Bonjour, je suis étudiant au baccalauréat en mathématique et j'aimerais savoir où et comment je peux me procurer la démonstration du dernier théorème de Fermat écrite par Wiles. Answered by Claude Tardif.
	Questions de Probabilités		2006-05-18
		From Guy: Le directeur d'un cirque a retenu cinq numéros pour composer son spectacle : les chiens savants, l'illusioniste, les clowns, les tapézistes et les acrobates. de combien de façons peut il composer son spectacles? En supposant qu'il y ait équiprobabilité dans le choix de la composition du programme, calculer la probabilité de chacun des événements suivants: les clowns terminent le spectacle les acrobates débutent ou terminent le spectacle les trapézites suivent immédiatement les clowns les clowns sont séparés des chiens savants par les trapézistes et seulement par eux. Answered by Claude Tardif.
	Ordre des opérations		2006-05-15
		From Chantal: 2324/4-153+619= je sais pas comment calculer merci Answered by Claude Tardif.
	Volume d'un cône		2006-04-24
		From Christelle: Caroline décide de se servir de ses connaissances mathématiques pour "rouler" son petit frère: "Arthur, dit-elle, je te propose que nous mettions chaucun un euro dans l'achat d'un cône glacé. Je mangerai la première, jusqu'à mi-hauteur, et toi, tu auras la seconde moitié." Combien la part de Caroline représenterai-elle par rapport à celle de son petit frère s'il acceptait ? Answered by Claude Tardif.
	ABCD est un carré de 4 cm de côté		2006-03-06
		From Elodie: ABCD est un carré de 4 cm de côté. On découpe un peit carré AEFG d côté x. Que vaut x si l'aire de AEFG est la moitié de l'aire de ABCD? Answered by Claude Tardif.
	soustractions avec les heures		2006-03-01
		From Bossedi: Je m'appelle Bossedi et malheureusement j'ai un petit souci en ce qui concerne le calcul des heures! Je ne me rappelle plus comment s'effectue une addition ou un soustraction avec les heures comme par exemples 22h30-7h00. Merci infiniment de bien vouloir m'aider. P.S.: Je me souviens qu'une lectrice du surnom Jennifer avait deja poser ce genre de probleme, mais avec la seule difference que dans son cas, c'etait i j'ai bonne memoire, 09h45 moins 07h52! Quelques choses de ce genre. Dois-je +tot ercire 11h30-07h00? Answered by Claude Tardif.
	Des exercices complémentaires		2006-02-26
		From Nathalie: Bonjour, mon fils est en 2e année dans une école de Montréal. Il éprouve des difficultés en mathématiques. Auriez-vous des sites à me suggérer dans lesquels je pourrait trouver des exercices complémentaires à lui faire faire. Answered by Claude Tardif.
	probleme sin cos		2006-02-19
		From Thibault: mon probleme commence par: f(x)=sinx (sinx+1)+ cos²x donc en le dévellopant on trouve: f(x)= sin²x + sinx + cos²x et apres ce que je ne comprend pas est que par la suite on trouve: f(x)= 1+sinx qu'est-ce qui fait que l'on trouve ce resultat?? Answered by Claude Tardif.
	Petit Problème		2006-02-19
		From Jean-Philippe: 30 ouvriers travail 12 jours pour effectuer un travail. Combien 20 ouvriers vont-ils mettre à effectuer ce travail ? Hormis une règle de trois existe t-il un autre moyen d'arrivée à trouver une solution ? Answered by Claude Tardif.
	Matrice		2006-02-01
		From Kader: mon probleme est le suivant soit deux matrices carrees A et B d'ordre n qui sont anticommutatives AB= -BA , demontrer que au moins une des deux matrices n'est pas inversible si n est impair. je n'arrive pas a utiliser le fait que n soit impair, trouver le rapport entre n impair et inverse des matrices, je pars sur la base de DETAB=DETA*DETB Answered by Claude Tardif.
	probleme de matrice		2006-02-01
		From Un eleve: mon probleme est le suivant soit deux matrices carrees A et B d'ordre n qui sont anticommutatives AB= -BA , demontrer que au moins une des deux matrices n'est pas inversible si n est impair. Answered by Claude Tardif.
	exposant négatif		2006-01-23
		From Jean: je suis un grand-père qui veut aider sa petite fille : niveau 4ème 3 exposant -2 = -3 exposant -4 = 3 exposant -9 = Je vous remercie de votre aide. Corldialement. Jean Answered by Claude Tardif.
	L'objectif est de trouver		2005-11-27
		From Sandie: L'objectif est de trouver "a et n" : 2 = a.0,6-n 0,3 = a.2-n Answered by Claude Tardif.
	Une énigme échelle/échafaudage(ou boite)		2005-11-08
		From Christian: J'ai un problème & souhaite demander votre aide pour résoudre une énigme échelle/échafaudage(ou boite) Answered by Claude Tardif.
	problème de trigonométrie		2005-11-01
		From Manon: Soit un triangle ABC, de cotes a , b et c, avec A=45° et B=60°. Apres avoir demontre que 3a²-2b²=0 (que jai fais en utilisant la regle du sinus) et a²-2c²+2ac=0 (que jai fait en utilisant la regle du cosinus), vous montrerez que laire du triangle ABC peut sexprimer: { [ 3 + racine carre 3 ] / 12 } b² unites. Je ne sais pas comment arriver a cette expression de laire. Je narrive pas a exprimer c² et ac en fonction de b².. et je pense que ca pourrait vraiment aider.. puisque je suis arrive a letape: ac[(racine carre 3) / 4] avec ac = a² + c² - b² et a² = 2/3 b² ms c²= 1/3 b² + ac Answered by Claude Tardif.
	Inverse		2005-10-18
		From Pauline: Défi ! a et b désignent deux nombres distincts non nuls. Peut-on trouver un nombre à retrancher du numérateur et du dénominateur du quotien a/b pour obtenir son inverse b/a? Answered by Claude Tardif.
	2^(2^1954) est-il premier?		2005-10-04
		From Un eleve: 2(21945)+1 est-il premier? Answered by Claude Tardif.
	Partages inégaux		2005-09-29
		From Un eleve: Alex et julie ont ensemble 4728 .- euro Si Alex donne 538.- euro à Julie, ce dernier aurait alors le triple de Julie. Quelle est la somme possédée de chacun? Answered by Claude Tardif.
	Calcul dun profil fictif		2005-09-29
		From Mr madry loïc: je suis actuellement en formation pour devenir dessinateur projeteur en BTP ; je rencontre un problème vis à vis d'une égalité qui normalement devrait mettre acquise ( elle doit être issue de thalès ou de l'égalité des proportion ?) cependant, je n'arrive pas trouver le fondement de cette égalité. pourriez vous m'aider à éclaircir cette relation fondamentale afin de poursuivre mon étude sur le calcul de profil en travers (pour les travaux publics) . Answered by Claude Tardif.
	exercice!		2005-09-28
		From Un eleve: soit x et y deux nomres réels telque: 1 ≤ x2-x*y+y2 ≤ 2 1) Montrer que: 2/9 ≤ x4+y4 ≤ 8 2) Montrer que: x2*n+y2*n ≥ 2/32*n telque n est un nombre entier naturel et n≥3. Answered by Chris Fisher.
	Mon problème (né d'un retour aux conclusions du prix Nobel d'économie ) revisité		2005-09-27
		From Nzitat: Soit L un sensemble de distributions de probabilités. Désignons par p une distribution de probabilité quelconque. En clair p=(p0,..., pm) où m >0 est fini. Appelons Vi, i=1,...,n, une fonction définie sur L et à valeurs dans l'ensemble des réels. De même Wj, j=0,...n est une fonction définie sur L et à valeurs dans l'ensemble des réels. Vi, Wj sont définies ainsi pour tout p:.... Answered by Claude Tardif.
	Problème avec rapport point, prix...		2005-09-08
		From Nico: Le prix d'un diamant est proportionnel au carré de son poinds. Un diamant de 0.45 g vaut 7500euros. 1. Combie coute un diamant de 0.693 g ? 2. Quel est le poids d'une diamant valant 45000 euros ? Je vous demande pas de le raisoudre à ma place mais j'aimeré comprendre comment je peut calculé le rapport entre le point et le prix. Answered by Claude Tardif.
	Le prix d'un diamant est proportionnel au carré de son poinds		2005-09-07
		From Nico: Le prix d'un diamant est proportionnel au carré de son poinds. Un diamant de 0.45 g vaut 7500euros. 1. Combie coute un diamant de 0.693 g ? 2. Quel est le poids d'une diamant valant 45000 euros ? Je vous demande pas de le raisoudre à ma place mais j'aimeré comprendre comment je peut calculé le rapport entre le point et le prix. Answered by Claude Tardif.
	quel sont les plus grands diviseurs communs?		2005-09-07
		From Sylvain: quel sont les plus grands diviseurs communs? Answered by Claude Tardif.
	Exposant		2005-09-06
		From Enzo: Puis-je savoir combien donne 2 exposant 100 ? et 9 exposant 3012 ? Answered by Claude Tardif.
	5 points équidistants sur la surface d' une sphère		2005-08-15
		From Jean: J' aimerais placer 5 points équidistants sur la surface d' une sphère. Si vous aviez une formule simple pour un néophyte, cela m' aiderais beaucoup. Answered by Claude Tardif.
	combien de fruits de chaque sortes?		2005-06-13
		From Halloy: j'ai un panier de 32 fruits au total dans mon panier, j'ai 3 fois plus de bananes que de pommes et 4 fois plus de poires que de pomme. Combien il y a de bananes, de poires et de pommes dans mon panier? Answered by Claude Tardif.
	problème de math		2005-06-03
		From Nadia: 1* La somme de 3 multiples de 6 consécutifs est 72.Quels sont ces nombres? 2* Dans la fabrication d’un alliage, on utilise 5g de manganèse pour 32g de fer. a) Quelle quantité de manganèse retrouve-t-on dans un morceau de cet alliage s’il contient 512g de fer? 00015166 b) Quelle est la masse totale de ce morceau si le fer et le manganèse en sont les seules composantes? 3*... Answered by Claude Tardif.
	Problème de géométrie		2005-04-29
		From Christian: C un cercle de centre I et de rayon 3 cm. SORT est un carré inscrit dans le cercle C M est un point quelconque de C Calculer la somme des carrés des distances de M aux sommets du carré (MS2 + MO2 +MR2 + MT2) Cette somme dépend-elle de la position de M sur le cercle ? Answered by Claude Tardif.
	Un repère orthonormal		2005-04-26
		From Ylène: Dans un repère orthonormal, le point A a pour coordonnées (-2;3) et le point B a pour (4;-5). A partir des coordonnées des points A et B on propose les calculs suivants: a/ (-2+4 sur 2 ; 3-5 sur 2) b/ (4+2; -5-3) c/ racine carré (4+2)²+(-5-3)² dans chaque cas, quelle est la notion géométrique ainsi mise en évidence? Answered by Claude Tardif.
	mod n		2005-04-26
		From Jean: Réecrire (5A27)en base 16 changer en base 8 ( (2n)!+ 1) (mod n) (1-764n) (mod n) (n+1)exposant 78355 (mod n) PPCM(n!+1 , n!) Answered by Claude Tardif.
	P(x+1)-P(x)=x		2005-04-21
		From Etienne: ~P(x)=a x3+ b x2+ c x ~P(x+1)-P(x)=x2 question: trouver les trois nombres a,b et c. Answered by Claude Tardif.
	Une réduction de 40%		2005-04-21
		From Isabelle: une famille composée de 3 enfants, et 2 adultes partent en expédition. ils payent au total 80€ sachant que les enfants bénéficient d'une réduction de 40% combien payent les parents et les enfants ? Answered by Claude Tardif.
	Avec les chiffres 1 3 4 6...		2005-04-14
		From Ambre et Miel: avec les chiffres 1 3 4 6 utilisé une seule fois chacun soit en div multipl addit ousoustr je dois avoir 24 comme résultat Answered by Claude Tardif.
	1 ellipsoïde et une sphère		2005-04-04
		From Tihon: Dans le cadre de mon mémoire réalisé à l'université de Liège (Belgique), je suis amené à savoir si 1 ellipsoïde et une sphère ont ou n'ont pas d'intersection...Quelqu'un peut-il m'aider?? Answered by Claude Tardif.
	La limite de l'aire du domaine colorié		2005-03-21
		From Rita: bonjour un petit problème qui m'a l'air bien compliqué et je n'est pour le moment aucune pistes pour demarré un carré de coté 1 est divisé en 9 carrés identiques et le carré central est colorié chacun des 8 carré qui restent est à son tour divisé et colorié suivant le meme procédé et on continue indéfiniment quelle est la limite de l'aire du domaine colorié? Answered by Claude Tardif.
	6 poules pondent 6 oeufs en 6 jours		2005-03-01
		From Nathalie: SACHANT QUE 6 POULES PONDENT 6 OEUFS EN 6 JOURS, COMBIEN 12 POULES PONDENT D'OEUFS EN 12 JOURS? Answered by Claude Tardif.
	l'aire d'un carré		2005-02-24
		From Un eleve: calculer l'aire d'un carré parfait sachant que les diagonales mesurent 8 mètres Je ne sais pas comment lui expliquer. Answered by Claude Tardif.
	le système RSA		2005-02-19
		From Un eleve: Je suis actuellement en classe préparatoire MP au lycée Henri Poincaré de Nancy et je souhaiterais obtenir des informations sur l'exponentiation modulaire car je réalise un TIPE sur la cryptographie et plus particulièrement le système RSA. pourriez-vous m'indiquez en quoi consiste l'exponentiation modulaire et comment cela fonctionne. Answered by Claude Tardif.
	il y a 1/6 de voitures bleues,		2005-01-24
		From Facrice: il y a 1/6 de voitures bleues, 2/9 de voitures rouges, 5/12 de voitures blanches et 1/8 de voitures vertes. Sachant que 15 voitures sont d'une autre couleur. Combien y a t il de voitures de chaque couleur. Answered by Claude Tardif.
	convertir une duree en heure et minute		2005-01-12
		From Sébastien: pouvez vous me donner la formule permettant de convertir une duree en heure et minute precise pour exemple : 589 minutes donne 10h35min. Quelle serait donc la formule pour passer directement de 589 min a 10h35 (sans avoir 9h81)? Answered by Claude Tardif.
	-1 exposant 4		2004-12-19
		From Denis: ma question est : -1 exposant 4 = ? Quand nous avons une base négative sans parenthèse comme ma question Answered by Diane Hanson.
	J'ai deux fois l'âge que tu avais quand		2004-12-03
		From Un eleve: Julien dit à Nicolas:"J'ai deux fois l'âge que tu avais quand j'avais l'âge que tu as.Quand tu auras l'âge que j'ai la somme sera égale à 63".A toi de trouver l'âge de Julien et de Nicolas. Answered by Claude Tardif.
	Nombre premier		2004-11-01
		From Katia: Pouvez-vous me dire comment savoir si un nombre est premier? Answered by Claude Tardif.
	programme de tracé		2004-10-21
		From jean-yves: pourriez vous me donner la définition de: qu'es ce qu'un "programme de tracé" Answered by Claude Tardif.
	La multiplication d'un nombre par 137		2004-10-19
		From Jacques: En posant la multiplication d'un nombre par 137, un élève a oublié de décaler vers la gauche le troisième produit partiel. Il trouve un résultat qui est inférieur de 22860 au bon résultat. Quel était le nombre multiplié? Justifier. Answered by Claude Tardif.
	Un problème de math		2004-09-10
		From Sophie: (V est en fait le signe de la racine carrée) (3 / V27) x ( V75 ) = ??? Answered by Claude Tardif.
	(x+y)^n = x^n + y^n + Z		2004-03-18
		From Jean-Sébastien: Bonjour, je me m’appelle Jean-Sébastien et je suis étudiant en secondaire 4. Je me demandais s’il est possible de développer le terme (x+y)n, lorsque n est un entier positif. Il est évident que xn+yn fera partie de la réponse mais comment définir le reste (Z dans l’exemple ci-dessous)? (x+y)2 = x2+y2+2xy (x+y)n = xn+yn+ Z P.S. : Une preuve mathématique démontrant la possibilité ou l’impossibilité du problème serait grandement appréciée, merci. Answered by Claude Tardif.
	Marie achète un croissant et une tartelette		2004-02-01
		From M. et Mme Simoneton: Marie achète un croissant et une tartelette. Elle paie 1,64 € Isabelle achète un croissant et un pain au chocolat. Elle paie 1,51 € Marc achète un poain au chocolat et une tartelette. Elle paie 1,77 € Trouver le prix d'un croissant, d'une tartelette et d'un pain au chocolat. Answered by Claude Tardif.
	Projections quadratiques		2003-12-14
		From Jennifer: Je vous serais très reconnaissante si vous pouviez m'expliquer : pourquoi la moyenne des projections quadratiques d'un segment sur un axe (en 3D) est égale à a*a/3 sachant que "a" représente la longueur de ce segment et que toutes les orientations du segment sont également probable. Answered by Claude Tardif.
	Des tables trigonométriques		2003-11-20
		From Jean-Jacques: Je suis à la retraite et en train de mettre à jour mes connaissances en trigonométrie. On peut facilement trouver les rapports entre les côtés d'un triangle droit ayant des angles secondaires de 30, 45 et 60 degrés, mais comment s'y prend-on pour calculer les rapports entre les côtés d'un triangle droit ayant des angles secondaires de valeurs intermdiaires. En d'autre mot, comment s'y prend-on pour faire le calcul détaillé des tables trigonométriques. J'ai cherché en vain dans divers textes de géométrie la réponse à cette question. Merci à l'avance pour l'attention que vous porterez à ma requête. Answered by Claude Tardif.
	Les 3 maisons		2003-11-16
		From Amandine: Sur la figure ci-contre on peut voir 3 maisons A, B et C nouvellement construites. Toutes les 3 doivent être reliées au gaz, à l'eau et à l'électricité. Cependant, tous ces raccordements doivent impérativement avoir lieu dans un même plan et les câbles et autres canalisations ne peuvent pas se croiser. Comment doit-on s'y prendre pour relier les 3 maisons à l'eau, au gaz et à l'électricité? Answered by Claude Tardif.
	Nombre d'or		2003-10-31
		From Claude: Comment démontrer que si a/b est égal au nombre d'or alors a+b/a est égal aussi au nombre d'or Comment faut t il choisir a et b pour que le puzzle de lewis caroll soit réalisable? on sait déjà que les nombres 8 et 5 ainsi que 6 et 3 ne sont pas valables. Answered by Claude Tardif.
	Hauteur d'un tétraèdre irrégulier		2003-08-29
		From Thibault: Je cherche à connaître comment calculer la hauteur d'un tétraèdre irrégulier (aucune arêtes égales) en ne connaissant que la longueur des arêtes. Answered by Claude Tardif.
	Opérations de base		2003-07-05
		From Anne-Marie: Je m'appelle Anne-Marie et je suis enseignante de 5e année à l'école Domaine des copains de Balmoral au Nouveau-Brunswick. Récemment, j'ai participé à un concours intitulé: Budweiser King Pack Nascar Hat Promo. Afin de réclamer le prix, qui est une casquette, je devais répondre à une question réglementaire. Il s'agissait d'une phrase mathématique qui se présentait comme suit: 4 x 26 - 24 / 8 = qui se lit: 4 fois 26 moins 24 divisé par 8 Answered by Claude Tardif.
	Fractions		2003-05-10
		From Jacques: Voici la question qu'il pose: 2 x (1/2+1/4) + 3 + 2 x (1/3-1/4). La reponse est 4 2/3. Pourriez m'expliquer etapes par etapes ce que je dois faire. Answered by Claude Tardif et Diane Hanson.
	Soustraction avec les heures		2003-04-08
		From Jennifer: Je m'appelle Jennifer et malheureusement j'ai un petit souci. Pour le calcul des heures c'ets à dire je ne me rappelle plus comment s'effectue une addition ou un soustraction avec les heures comme par exemples 9h45-7h52. Si vous pouviez m'aider j'ens erais trés contente. Answered by Diane Hanson and Claude Tardif.
	Un polyedre convexe		2003-04-07
		From Hubert: quelle sont les conditions nécessaire pour former un polyedre convexe avec un seul type de polygone? Answered by Claude Tardif.
	La somme de 51 nombres entiers consécutifs est 1785		2003-04-01
		From Katrine et Armand: La somme de 51 nombres entiers consécutifs est 1785, quels sont ces nombres? (indication : on rappelle que pour tout entier P, on a 1 + 2 + ....+ P = P (P + 1) / 2). Answered by Claude Tardif et Penny Nom.
	Le terme		2003-04-01
		From Francine: Je suis une enseignante de 5e/6e et j'aimerais savoir comment on traduit le terme "array" en français. Answered by Claude Tardif.
	Nombre Premier		2003-02-24
		From Un Etudiant: Montrer que si p est facteur premier de 22n + 1 alors (p-1) est multiple de 2n+2 Answered by Claude Tardif.
	les formules d'aire et de volume de les solides		2003-02-01
		From Annie: Je cherche le nom des mathématiciens qui ont découvert les différentes formules d'aire et de volume de tous les solides ( boule, cube, les prismes, cylindre, cône, pyramide, polyèdres réguliers). Je cherche aussi à trouver comment ils ont démontré l'exactitude de ces formules. L'important, c'est de connaître le nom des mathématiciens qui ont découvert ces formules. Answered by Claude Tardif.
	La longueur d'une corde		2003-01-22
		From Un eleve: Existe-t-il une formule permettant de calculer la longueur d'une corde quelquonque d'un cercle connaissant uniquement le rayon de celui-ci? Si oui quelle est-elle? Answered by Claude Tardif.
	le matricule		2003-01-12
		From Sirkka: "Dans un pays totalitaire, tous les habitants ont un matricule composé de 5 chiffres. Les policiers se reconnaissent au fait que le premier chiffre de leur matricule est strictement supérieur à la somme des quatre autres. ex: 90124 9>0+1+2+4=7 Combien y a-t-il (au plus) de policiers?" Answered by Claude Tardif.
	des conversions de bases différentes		2003-01-04
		From Christian: Je cherche désespérément la (les) règle(s) pour réussir des conversions de bases différentes : de base x vers base y. Answered by Claude Tardif.
	Un peu de trigonométrie		2002-12-16
		From Hubert: J'ai 37 ans et les mathématiques sont relativement loin dans ma mémoire, je voudrais savoir s'il existe un méthode pour résoudre une équation du type. a1*cos(x) + a2*sin(x) + a3*cos(2x) + a4*sin(2x) + a5 = 0 Answered by Claude Tardif.
	Volume d'une calotte ellipsoidale		2002-12-11
		From Fabien: Quel est le volume d'une calotte d'ellipsoide de hauteur h (ellipse de longueurs d'axes a, b, et c)? Je souhaite une formule exacte, un développement limité, voire une intégrale à estimer numériquement. Quelle méthode pour le calculer ? Answered by Claude Tardif.
	Une plantation d'arbres		2002-12-10
		From Eric: créer une plantation d'arbres de 6 rangées de 5 arbres, pour un total de 15 arbres . Je n'arrive pas à trouver la forme géométrique.Merci de me répondre que j'ai l'air moins bête envers mon gamin. Answered by Claude Tardif.
	Un exposant negatif		2002-11-25
		From Vinny: Moi je n'ai aucune idée de ce que vaut un exposant negatif com 3^(-5) ou encore 3^(-4/3) de meme pour un exposant rationnel 3^(4/3) Answered by Claude Tardif.
	Quatre vingts		2002-11-18
		From Jacques: pourqoui les Francais disent quatre vingts pour 80 Answered by Claude Tardif.
	100 centimètres		2002-11-13
		From Un élève: je voudrais savoir la contenance de 100 centimètres cube en litre? Answered by Diane Hanson.
	Les unités linéaires		2002-11-12
		From Sandy: je me demande qu'est ce qu'une unité linéaire, mesures de surface et des mesures de volume. je voudrais aussi savoir quelle est la règle de transformation pour les unités linéaires, les mesures de surface et les mesures de volume Answered by Claude Tardif.
	Un triangle équilatéral		2002-10-27
		From Un eleve: Soit ABC un triangle équilatéral construit dans le sens direct. Le point D est symétrique de A par rapport à la droite (BC), et le point E est symétrique de B par rapport au point C. L'intersection des droites (AD) et (BC)est notée H. On pose AB=a. Je dois calculer les longueurs AD et AE en fonction de a. Je dois montrer que le triangle ADE est équilatéral. J'arrive a prouver qu'il est isocèle en E mais j'aimerai trouver que AD=DE. Answered by Claude Tardif.
	La limite de (x(n))		2002-10-01
		From Une étudiante: 3) Soit L, le point ayant pour abscisse la limite de (x(n)) a) Exprimer la distance M(n)L en fonction de n b) Déterminer le plus petit entier naturel n(o) pour lequel la distance Mn(o)L est inférieur à 0,01 c) Justifier alors qu'à partir du rang n(o), tous les points M(n) sont situés dans le segment de centre L et de rayon 0,0 1 Answered by Claude Tardif.
	Comment fait on pour justifier que...		2002-09-30
		From Lucie: Comment fait on pour justifier que p au carré est égal à 2 fois q au carré? Answered by Claude Tardif.
	3 maisons		2002-08-23
		From Wilfrid: voila j'ai une petite énigme a vous proposez il y a 3 maisons chaque maisons doit être reliées par une arrivées d'eau , d'électricité et par le gaz sans que les lignes ne se croisses pouvez vous me dire si c'est possible car moi j'ai essayé et ne suis pas arrivé je vous joint un exemple pour que vous compreniez mieux merci d'avance Answered by Claude Tardif.
	Espaces vectoriels		2002-08-18
		From Bacar: Comment montrer que trois (ou plus que trois) sous espaces vectoriels sont en somme directe. Answered by Claude Tardif.
	Un hectolitre		2002-06-12
		From Un eleve: Pouvez-vous me dire combien d'hectolitres y a t-il dans un mètre cube (m3)? Answered by Diane Hanson.
	La traduction anglais		2002-05-27
		From Une etudiant: je voudrais savoir la traduction anglais de : homothétie (mot de niveau intermédiaire (6-9)) apothème (mot de niveau internédiaire (6-9)) parce que je ne les trouve pas. Answered by Chris Fisher at Claude Tardif.
	Un problème mathématique		2002-04-23
		From Mylène: En me servant de ces chiffres 1 2 3 4 5 6 je dois les utiliser seulement qu'une fois en faisant l'équation suivante. ? X ? X ? __ __ ? ? X ? = 2 Answered by Claude Tardif.
	Un empilement de spheres		2002-04-16
		From Sébastien: Lorsque j'etais encore a l'universite je me souviens qu'un prof nous avez dit, sans le demontrer (ce n'est pas bien du tout de sa part) que l'espace minimal qui existe dans un empilement de spheres est de l'ordre de 26% Voici plusieurs jours que je cherche a resoudre ce probleme de geometrie, et je n'arrive meme pas a trouver comment l'aborder. Answered by Claude Tardif.
	Nombres algebriques sur Q		2002-04-11
		From Un eleve: On sait que le corps des nombres algebriques sur Q est algebriquement clos. A priori partant d'un polynome f a coefficients algebriques sur Q on devrait pouvoir un trouver un polynome g a coefficients rationnels dont une partie des racines est constituee de racines du premier. y-at-il un algorithme qui permet qui permet le passage de f a g ? Answered by Claude Tardif.
	Problème de traduction		2002-04-11
		From Philippe: Je suis professeur de mathématiques en collège et j'aimerai que la classe de 5ème, qui a une spécialité "Anglais", fasse un cours de mathématiques en anglais. N'étant pas moi même trés fort en mathématiques version anglaises, je vous sollicite donc pour répondre à certaines de mes questions. Par exemple, je me demande comment on dit " 3 fois 5" en anglais. "2 plus 2" se dit "2 and 2 is...". J'ai des problèmes avec la multiplication, la soustraction (" minus" ou "out of" ?), et la division. De même , comment dit-on "2/3". J'ai aussi des problèmes pour le vocabulaire mais je pense pouvoir le résoudre en utilisant un bon dictionnaire. Ma question est donc: Existe-t-il des sites qui propose ce genre de traduction? Answered by Claude Tardif.
	Conversion de m2 en cm2		2002-03-10
		From Carole et Francis: Mon enfant est en 6ième année, il avait le problème suivant à faire dans un test: Trouve l'aire d'un rectangle mesurant 9 m par 4 m; donne ta réponse en m2 et en cm2? Voici la solution de mon fils: 9m x 4m = 36m2 9m = 900cm 4m = 400cm donc 900cm x 400cm = 360 000cm2 D'après moi sa réponse est bonne, j'aimerais avoir une confirmation puisque l'enseignante lui dit qu'il y a erreur. Answered by Claude Tardif.
	Les quantités d'aliments		2002-03-09
		From Benhacine: soient les aliments A1, A2, A3.....An contenant respectivement le nutriment "a" aux quantités a1, a2, a3, et an sachant qu'un organisme a besoin d'une quantité connue de nutriment "a" égale à "Be", Ayant: A1.a1 + A2.a2 +.....+ An.an = 100.Be et A1 + A2 + A3 +....+ An = 100 Quelles seront les quantités d'aliments A1, A2, et An qui satisferont le besoin défini "Be" de l'organisme? Answered by Claude Tardif.
	A/B = C/D		2002-03-06
		From Un eleve: Démontrer que si A sur B et = à C sur D, alors AxD et = à BxC. Answered by Claude tardin.
	Une autre bille de rayon différent		2002-02-27
		From Sarah: une bille de 6 cm repose au fond d'1 cylindre droit dont la base est un disque de rayon 10 cm. On verse de l'eau dans le cylindre de façon à recouvrir exactement la bille. Démontrez que l'on peut remplacer la bille par une autre bille de rayon différent (mais supérieur) de sorte que l'eau initialement versée recouvre exactement cette nouvelle bille Answered by Claude Tardif.
	Ses points de discontinuités est les irrationnelles		2002-01-08
		From Un eleve: Je voudrait montrer qu'il n'existe pas de fonction de R--->R tels que ses points de discontinuités est les irrationnelles, en utilisant la methode de "baire". Answered by Claude Tardif.
	Fraction rationnelle		2001-12-11
		From Audrey: réduire en une seule fraction et simplifier. (4-2x+x2)/(2+x) - (x+2) Answered by Claude Tardif.
	l'équation d'une rotation dans un graphique cartésien		2001-11-14
		From Ghaith: je d6sir que vous me rafraichissez un peu la mémoire s.v.p. j'aimerai savoir l'équation d'une rotation dans un graphique cartésien merci Answered by Claude Tardif.
	Minesweeper		2001-10-24
		From Un eleve: J'espere que vous pourrez m'aider. Est ce que vous connaissez un algorithme ou une strategie de resoulutiom pour le jeu du demineur (8x8 avec 10 mines)(Minesweeper). Answered by Claude Tardif.
	Un nombre entier relatif ou reel		2001-06-13
		From Omar: J'aimerais savoir c'est quoi un nombre entier relatif ou réel? Answered by Claude Tardif.
	Les tableaux de conversions		2001-05-03
		From Jean-Jacques: Sur quel site est il possible de trouver tous les tableaux de conversions de mètres,kg,litre,m2,m3 Quelle est la relation entre les m3 et les litres 1 m3 = 1000 litres = 1000 kg? Answered by Claude Tardif.
	coercif		2001-04-17
		From Sonia: J'ai juste une petite question de vocabulaire à vous soumettre: connaitriez vous la traduction en anglais du mot : "coercif", que je n'arrive pas à trouver sur le net! Answered by Claude Tardif.
	Les dimensions d'un rectangle		2001-04-09
		From Un elévè: 1. Les dimensions d'un rectangle sont a et b Si on augmente a de 3cm et b de 2cm, l'aire du rectangle augmente de 37 cm2, mais si on diminue a de 2cm et b de 1cm, l'aire du rectangle diminue de 16cm2. Quelles sont les valeurs de a et b? 2. Quelle est la valeur numerique de l'expression (ac+bd)+(ad-bc) sachant que a+b=1 et que c+d=1? Quelles sont les regles essentielles qui me manquent pour resoudre ceci? Answered by Claude Tardif.
	preuve par 9		2001-04-04
		From Michel: Pourriez-vous m'expliquer en détail comment fonctionne la preuve par 9 (pour une division et une multiplication). Je sais l'appliquer mais je ne sais pas pourquoi ça marche. Je ne retrouve pas la démonstration. Merci de m'aider. Exemple . 17x2=34 ; preuve par neuf : 1+7=8 ; 8x2= 16 ; 1+6=7 et 3+4=7, on peut donc supposer (sans affirmer) que cette multiplication a un résultat juste car la preuve par 9 est bonne, 7=7. Comment fonctionne cette preuve par 9??? Answered by Claude Tardif.
	Le volume d'un ellipsoïde		2001-03-17
		From Lise: Je cherche à calculer le volume d'un ovoide, avez-vous une formule? Answered by Claude Tardif.
	Recherhce sur pi et exponentielle		2001-03-17
		From Cyril: étudiant a la fac de sciences de montpellier je cherche des informations concernant la demonstration suivante: "comment prouver que pi et exponentielle sont irrationnels?" Answered by Claude Tardif.
	Zero		2001-03-15
		From Alexandre: j'aimerais beaucoup savoir si le chiffre zéro est considéré comme étant soit: pair impair pair et impair à la fois ni pair ni impair. Answered by Claude Tardif.
	Solides		2001-02-26
		From Joanie: J'ai présentement un projet à faire, je dois le remettre avant vendredi. Je dois trouver entre 31 ou 35 solides: prismes et pyramides J'ai a donner : le nom de chaque solide; son dessin; et le dessin de chaque solide décomposé en toute ses parties. Answered by Claude Tardif.
	Un lièvre et un chien		2001-02-20
		From Ganay Alain: Un lièvre à 9 sauts d'avance sur un chien. 7 sauts du chien égalent 11 sauts de lièvre. Quand le chien fait 4 sauts , le lièvre en fait 6. En combien de sauts le chien prend-il le lièvre? Answered by Claude Tardif.
	Boulier		2001-02-13
		From Un élève: Comment se sert-on d'un boulier (non asiatique) comportant 10 rangées de 10 boules chacune? Answered by Claude Tardif.
	Radical de n		2001-01-03
		From Un eleve: j'aimerai savoir ( d.Levy), élève de 1éS ce que signifie la phrase: radical de 2 + radical de 3 est un nombre négatif ( niveau intérmédiaire). Answered by Claude Tardif.
	Calculer la hauteur de chute de cette pierre		2000-12-16
		From Marcus: Une pierre tombe au fond d'un puit, à 5 secondes on entend un son (de la pierre). Calculer la hauteur de chute de cette pierre en tenant compte de la vitesse du son = 340m.s-1 Il faut savoir que pour la chute libre v= g.t ; h = 1/2 g.t2 ; v = 2g.h g intensité du champs de pesanteur = 10 ; h hauteur de chute. Answered by Claude tardif.
	racine carrée		2000-11-24
		From G. Bigorgne: Quel est donc l'origine de l'expression "racine carrée" ? Pourquoi avoir choisi cette expression ? Answered by Claude Tardif.
	Le volume d'une sphère		2000-09-17
		From Pitmill: merci de me donner la formule pour trouver le volume d'une sphère. Answered by Harley Weston.
	isomorphisme		2000-08-10
		From Romain Kroes: Pour les beoins d'un ouvrage d'économie que je suis en train de terminer, pouvez-vous me dire qui est (sont) l'inventeur de l' "isomorphisme" en mathématiques (calcul tensoriel)? Answered by Claude Tardif.
	Un polyedre ayant comme face 20 triangles		2000-08-02
		From Sonia: J'aimerai savoir comment s'appelle un polyedre ayant comme face 20 triangles équilatéraux égaux. Answered by Chris Fisher.
	Exposant à la 0		2000-07-04
		From Sylvie: J'aimerais savoir combien fait 0 exposant 0. Answered by Claude Tardif.
	Combien y aura t il de 9 dans la réponse?		2000-06-17
		From Marie: J'ai lu une énigme mais je n'ai pas la réponse."si l'on divise 123 456 789 par 999 999 999, combien y aura t il de 9 dans la réponse?" Answered by Claude Tardif.
	le nombre d'or		2000-06-14
		From Belhaj Saad: quel est le nombre d'or? Answered by Claude Tardif.
	Sens d'un mot		2000-06-01
		From Edward Brisse: Serait-il possible de connaître le sens précis du mot "PORISME". Exemple : "le porisme de Poncelet". Answered by Claude Tradif.
	la dimension fractale		2000-05-01
		From François RIVOIRE, Julien CHOLLET et Alexandre DECOSTER: nous sommes étudiants en première année MPSI en école d'ingénieur ISEN ( Institut supérieur d'électronique du Nord ). Nous avons choisi les FRACTALES ( ou plus précisément sur la dimension fractale et topologique ainsi que sur les suites logistiques) comme sujet de TIPE; serait-il possible que vous nous envoyez des démonstrations mathématiques ou des conseils car jusqu'ici nous avons eût beaucoup de mal à trouver des démonstrations se rapportant à ce sujet, Answered by Claude Tardif.
	Resolution of the equation f(x)=0		2000-04-01
		From Naoufal: How can i evalf the equation f(x)=0 with f function . Can you ansear me in french thank you very much Answered by Claude Tardif.
	Explications		2000-03-05
		From Jean Barbe: Comment expliquer l'algèbre à un adolescent du Sec. 111 Answered by Claude Tardif.
	Point de partage		2000-02-21
		From Sebastian Murciano: J'aurais besoin de savoir où je peux trouver de l'informations, ou est-ce que vous pouvez me donner de l'information sur : Point de partage d'un segment étudié en Secondaire 4. Answered by Claude Tardif.
	La bissectrice de l'angle ABC		2000-02-16
		From Laurent Gauthier: Est-ce redondant d'ecrire "angle ABC" avec un accent circonflexe sur le B? Peut-on ou devrait-on se contenter d'ecrire soit ABC (avec l'accent), soit l'angle ABC (sans accent) ? Le contexte dans lequel ceci apparait est le syntagme "la bissectrice de l'angle ABC", c'est-a-dire que je me demande si on devrait ecrire "la bissectrice ABC " (avec accent), "la bissectrice de l'angle ABC" (sans accent) ou "la bissectrice de l'angle ABC" (avec accent). Answered by Claude Tardif.
	Septante		1999-12-18
		From Guillaume Bessis: Pourqoui et depuis quand en France emploie-t-on l'expression 'soixante-dix' et non septante pour désigner 70 ? (idem pour 90 et nonante) Answered by Claude Tardif.
	Les equations		1999-12-09
		From Enciso Alberto: j'ai les equations suivantes: X1=Rs + A1/(B+W^2) X2=Rs + A2/(B+W^2) X3=Rd + A3/(B+W^2) X4=Rd + A4/(B+W^2) X5=Rg + A5/(B+W^2) X6=Rg + A6/(B+W^2) dont les coefficients Ai (i=1,2,..) et B sont constants (mais on ne conais pas leur valeur) et Rs, Rd, et Rg sont inconnues. Nous pouvons constater que la dependence de ces differentes expessions en fonction de W^2 est identique. Le tracé de l'une de ces expressions en fonction d'une autre est donc une driote. . . . Answered by Claude Tardif.
	ln(x+3)+ln(x+2)=ln(x+11)		1999-11-24
		From Thibault Portevin: "Résolvez l'équation : ln(x+3)+ln(x+2)=ln(x+11)" Je suis bloqué, pourriez-vous m'aider? Answered by Claude Tardif.
	la pantographie		1999-11-18
		From Erick et Christine: Nous recherchons la définition de pantographie voltaïque, que représente cette "figure" ? est-ce qu'on peut en définir une unité de mesure ? Answered by Claude Tardif.
	logarithme neperien		1999-11-10
		From Louise Kieffer: D'où provient la valeur e ( 2,7....) des logarithmes népériens ? Answered by Claude Tardif.
	15 films		1999-11-09
		From Hebert: Un touriste revient de vacnces avec 15 films: 2 films de photos d 'Italie 8 films de photos de Grèce 5 films de photos de Turquie. Aucune marque distinctive ne permet d'identifier les films. Pour des raisons financières le touriste ne fait développer à son retour que 11 de ces 15 films qu'il choisit au hasard.NB : on donnera les résultats sous forme décimale approchée à 10-4 près. Combien y a t il de choix différents possibles de 11 films parmi les 15 ? Quelle est la probabilité que , parmi les 11 films développés, il y ait: ... Answered by Claude Tardif.
	Gravity equation		1999-10-21
		From Jean-Marie Le Ray: J'ai dû traduire un texte avec la formule "gravity equation", que j'ai rendue par "équation de gravité", sans absolument savoir de quoi il s'agit. Quelqu'un sait-il si cela est juste et ce qu'est exactement une "gravity equation"? Answered by Claude Tardif.
	Derivées partielle		1999-10-19
		From Arnaud Flandin: Quel est la definition des derivées partielle Answered by Claude Tardif.
	La longueur des segments formant un triangle		1999-10-05
		From Michel Provencher: Connaissant la longueur des segments formant un triangle,comment détermine-t-on chacun de ses angles si: il S'agit d'un triangle rectangle Sachant que la somme des angles d'un triangle est de 180 degrés et sachant par conséquant qu'un des angle est de 90 degrés (triangle rectangle) il reste donc, 90 degrés à partager entre les 2 angles restant. Si les 2 segments formant l'angle droit sont de même longueur on obtient un angle de 45 degrés pour les angles restant soit 1/2 angle droit ce qui ne me pose évidement aucun problème. Quel relation, S'il y en a une, y a t-il entre la longueur de ces 2 segments et les angles restants. il S'agit d'un triangle quelconque Answered by Claude Tardif.
	Application surjective		1999-09-30
		From Charass: je suis étudiant en premiere année de deug et je cherche apres une definition si vous pouviez m'aider, ça serait sympa. qu'est ce qu une application subjective? Answered by Claude Tardif.
	Traduction		1999-09-27
		From Beatrice: Pouvez-vous me traduire en anglais les terms ci-dessous? Intrégration ensembliste Espaces vectoriels normés Traitement statistique du signal Equations aux dérivées partielles ... Answered by Claude Tardif.
	Le salinon d'Archimèdre		1999-03-11
		From Don Craig: I am trying to find the English translation of "Le salinon d'Archimèdre" and would appreciate any help. This is a figure, presumably studied by Archimedes, created from 4 semi-circles. Since I can't draw it for you, I will try to describe it with the help of the 5 collinear, horizontal points below. . . . . . A B C D E A semi-circle is constructed on AE as diameter (let's say above AE). Two more semi-circles are then constructed with diameters AB and DE on the same side of the line AE as the first semi-circle (above it). Finally, a fourth semi-circle is constructed on diameter BD, this time on the opposite side of the line AE from the others (i.e. below the line). These semi-circles and the region enclosed by them constitute what is called in French "Le salinon d'Archimèdre". If you know the English name of this curve I would appreciate it if you let me know. Answered by Harley Weston.
	Maths		1999-01-11
		From Stephane Roissard: Soit ABC un triangle dans lequel les trois médianes sont de meme longueur. Montrer que ce triangle est quilatéral. Answered by Jack LeSage.
	Le sang humain		1998-10-06
		From Golden: Le sang humain contient approximativement 2,5 x globules rouges. Chaque globule a un rayon de 0,004 mm. Si on le place ces globules bout a bout, quelle est la longeur de la chaine en millimetres? En kilometres? Compare toi avec la circonference de la terre (24 000 km) (Travail avec exposants) Answered by Claude Tradif.
	Un angle solide		1998-05-06
		From Giol: Qu'est ce qu'un angle solide ?? J'ai beau chercher dans mes documents, je ne trouve rien de bien convaincant sur le sujet si ce n'est une définition qui me semble bien vague et creuse ... En vous remerciant de votre attention ( puissiez vous illustrer votre réponse par un exemple, s.v.p...) Bonjour, Answered by Chris Fisher.
	les fractions		1998-02-24
		From Colette Huguenin: Bonjour je révise mes math de tout les secondaire et le livre louer la bibliothèque n'est pas entier voici le genre de problêmes qui me bloque (5 4/5+1/2)divisé 1/3 je sais que je dois commencer par la parenthèse mais...je fait quoi comme opération avec le 5? dois-je le multiplier ou l'additionner ou.......????? si je pouvais seulement avoir la base des fractions je redébloquerais surement Answered by Diane Hanson.
	Volume tetraedre		1998-02-13
		From Solecki Yannick: j`aimerais savoir s`il existe une formule de calcul simplifie pour trouver le volume du tetraedre en fonction de ses cotes et sans utiliser une expression matricielle. Answered by Chris Fisher.
	Question de trigonométrie		1997-12-11
		From Jean-Pierre Quesnel: Je suis dans le désert et je parcours 1000 km à partir du point "A" jusqu'au point "B". Si je reviens au point "A" et fais une rotation de 8 degrés en faisant un autre 1000 km, quelle sera la distance en km entre les points "B" et "C". Answered by Diane Hanson et Penny Nom.

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