







Soccer fans and cricket fans 
20180506 

From Chibo: In a survey of 60 sport fans, 45 enjoy soccer, 35 enjoy cricket and 10 do not enjoy either soccer or cricket, but some other sports.What percentage of sports fans enjoys both soccer and cricket? Answered by Penny Nom. 





Is a rectangle a parallelogram? 
20180228 

From ellie: is a rectangle a parallelogram? Answered by Penny Nom. 





A parallelogram, a rhombus and a rectangle 
20180207 

From Sambo: what do parallelogram, rhombus and rectangle have in common? Answered by Penny Nom. 





The modulus of a complex number 
20160729 

From Cheyenne: There's a question on my Summer Assignment I cant figure out. Here it is:
Find the absolute Value of the complex number. 5i
Please help? Answered by Penny Nom. 





Converting ml to g 
20160428 

From Lerato: I would like to know which formula should I use to convert ml to g? Answered by Penny Nom. 





The midpoints of the sides of a quadrilateral 
20160205 

From Andrea: The segments, joining, in order the midpoints of consecutive sides of a quadrilateral form a parallelogram. Answered by Penny Nom. 





Consecutive angles of a parallelogram 
20160128 

From Hanna: The consecutive angles of a parallelogram measures Answered by Penny Nom. 





Parallelogram area 
20150804 

From Nigel: To find the area of a parallelogram you multiply the base by the height of the parallogram, the height being determined by an imaginary line drawn at right angles to the base. However if I made a parallelogram with joints at each corner and maipulated it to an upright position where the base and sides were at 90 degrees to each other,, I could then simply multiply the base times the height to get the area. Since the sloping side of the parallelogram does not vary in my imaginary jointed model, why can I not simply multiply the base by the sloping side to get the area in the same way that I multiply the base times the height of a square to find its area ? I cannot find the answer to this on the internet although I have searched. Answered by Chris Fisher. 





A parallelogram inscribed in a circle 
20150204 

From narendra: how can we prove that a circular parallelogram is a rectangle? Answered by Chris Fisher. 





Percentages in a mixture 
20141002 

From viola: Hi there
can you help me convert the below so it makes 100% (individual %)
400 gr =
100 gr =
50 gr =
50 gr =
20 gr =
2 gr =
1 gr =
1 gr =
Be great to hear back from you
Thank you
V Answered by Penny Nom. 





Interior angles in a parallelogram 
20140830 

From xavier: so, one of my math homework questions requires me to know how to find out how to find the interior angles in a parallelogram, the question is, "how many interior angles does a parallelogram have?" Answered by Penny Nom. 





A number with all the digits different 
20140207 

From Jon: I'm not a mathematician but just curious. Is there a name for a number of up to ten digits where each digit is different,
i.e the equivalent of an isogram in linguistics? My online banking gives me a random 8digit number each time I log on
and it is rare to get one of the type I refer to. There must be calculable odds, but I'm only allowed one question!
Thanks in advance
Jon Answered by Harley Weston. 





The area of a parallelogram 
20131128 

From shivam: a parallelogram has sides 34 cm and 20 cm .one of its diagonal is 42 cm. calculate its area Answered by Harley Weston. 





A linear programming problem 
20130227 

From Kelley: A manufacturer of skis produces two types: downhill and crosscountry. Use the following table to determine how many of each kind of ski should be produced to achieve a maximum profit. What is the maximum profit? What would the maximum profit be if the time available for manufacturing is increased to 48 hours.

Downhill 
Crosscountry 
time available 
manufacturing time per ski 
2 hrs 
1 hr 
40 hr 
finishing time per ski 
1 hr 
1 hr 
32 hr 
profit per ski 
$70 
$50 

Answered by Penny Nom. 





How many students have neither brown hair or hazel eyes? 
20130120 

From Julie: There are 28 students in a class. 15 have brown hair, 17 have hazel eyes, and 10 have both. How many students have neither brown hair or hazel eyes? Answered by Penny Nom. 





A question about a parallelogram 
20121014 

From Renu: Question from renu, a parent:
ABCD is a parallelogram. BP and DQ are two parallel lines cutting AC at P and Q respectively. prove that BPDQ is a parallelogram Answered by Harley Weston. 





Probability 
20120823 

From Christine: In a study of alcoholics, it was found out that 40% had alcoholic fathers and 6% had alcoholic mother. Fourtytwo percent had at least one alcoholic parent. What is the probability that a randomly selected alcoholic will ... Answered by Penny Nom. 





If a parallelogram is a cyclic quadrilateral then it is a rectangle 
20120201 

From Kim: Show that if a parallelogram is a cyclic quadrilateral then it is a rectangle.
Hint: Observe that in a parallelogram ABCD we always have Triangle ABC is congruent to Triangle CDA. Answered by Robert Dawson and Chris Fisher. 





An equilateral triangle and some circles 
20120110 

From tushar: draw an equilateral triangle with side 6cm.draw 3circles with radii 3cm on each angular point of triangle.draw common tangent on each of two circles Answered by Penny Nom. 





A coin toss game 
20110829 

From Aniish: A and B alternately toss a coin.The first one to turn up a head wins.If no more than 5
tosses each are allowed for a single game,find the probability that the person who tosses
first will win the game?What are the odd's against A losing if she goes first? Answered by Penny Nom. 





The rate of change of the area of a parallelogram 
20110405 

From Gevork: Let a parallelogram have sides of 8 and 12 and let vertex angle A be decreasing at a rate of 2degrees per minute. Find the rate of change of the area of the parallelogram when angle A equals 30 degrees. Answered by Penny Nom. 





The diagonals of a parallelogram 
20110217 

From ginger: Find the diagonals of parallelogram where the the side is 40 and the bottom side is 15. Answered by Penny Nom. 





Determine if a point is inside a cube 
20101124 

From Ali: hi every one
i have a problem with cube
they told me to write a program that determine if a point is
inside a cube
so i need the equation of the cube to do the comparison.
in sphere it is easy
sqrt((xxp)+(yyp)+(zzp))<=radios
if u please could help me Answered by Robert Dawson. 





a^(2^n) 
20101022 

From Tim: I am trying to understand a^(2^n).
The hint they give is a^(2^(n+1)) = (a^(2^n))^2
I am writing a program that will solve a^(2^n) recursively but need to
understand the power before I begin.
I am currently pursuing writing (a) x (a^(2^(n1))) where the
(a^(2^(n1))) would be the recursive function call a n approaches 0.
Once n is 0, the result would be multiplied by a two more times.
Anyway, explaining these powers would be appreciated. I will most likely
complete the program before the answer but I want to understand the
logic of these powers. Thank you, Tim Answered by Stephen La Rocque. 





Converting kilograms to cubic metres 
20100716 

From Ilai: I want to convert kg to cubic metre Answered by Penny Nom. 





A probability tree 
20100520 

From Sandy: Children’s meals are being prepared for a large gathering. There is an equal number of chicken, hamburger, and fish meals. Each meal comes with a toy: a ball, a parachute toy, or a Frisbee. There are twice as many balls as Frisbees and an equal number of parachutes and Frisbees.
Use a probability tree to show the sample space and determine the probability that a meal consists of chicken or fish and comes with a ball as a toy. Answered by Penny Nom. 





Pyramids and parallelograms 
20100401 

From Vivi: Hi, my name is Vivi, and math teacher is giving a geometry test. I tend to forget how to find the surface area and volume of triangular pyramids and parallelograms. Do you have a way of remembering how to find the surface area? Answered by Harley Weston. 





Conditional probability 
20100326 

From Sandy: In a certain school, it is known that 80% of the students use the internet for school projects, 60% use email on a regular basis, and 90% use the internet for school projects or for email on a regular basis. A student from this school is selected at random
Determine the probability that the student used email, given that the student used the internet for school projects.
Sandy Answered by Penny Nom. 





How many people in total came to the museum that day? 
20100305 

From simon: 1354 people attended exhibition A and 1427 people attended exhibition B. 79% of people attended both exhibitions. How many people in total came to the museum that day Answered by Penny Nom. 





I want to convert my glaze percents into grams 
20100205 

From linda: I am a potter. I want to convert my glaze percents into grams.
ex. 20% of 20 lbs would equal how many grams?
is there a formula to figure this? Answered by Penny Nom. 





Linear programming using the Simplex Method 
20091228 

From William: A gold processor has two sources of gold ore, source A and source B. In order to keep his plant running,
at least three tons of ore must be processed each day. Ore from source A costs $20 per ton to
process, and ore from source B costs $10 per ton to process. Costs must be kept to less than $80 per day.
Moreover, Federal Regulations require that the amount of ore from source B cannot exceed twice the
amount of ore from source A. If ore from source A yields 2 oz. of gold per ton, and ore from source B
yields 3 oz. of gold per ton, how many tons of ore from both sources must be processed each day to
maximize the amount of gold extracted subject to the above constraints?
I need a linear programming solution or algorithm of the simplex method solution.
Not a graphical solution. Thanks. Answered by Janice Cotcher. 





Grams per square meter 
20090930 

From MANISH: how to calculate gsm given kg of 144 sheets and size in inches
example 28" x 22" & 16.3 kgs = ?gsm (of 144 sheets) Answered by Penny Nom. 





Grams to percent 
20090920 

From brandy: how do you convert 1.5 grams to a percent Answered by Stephen La Rocque. 





Rolling a six on the sixth roll 
20090504 

From Scott: What are the odds of rolling a die 6 times in a row and rolling a 6 only on the 6th try, but not any other time? And how is this calculated? Answered by Harley Weston. 





Ranking 6 players from 49 
20090324 

From liz: My daughter is having problems with this question,
if you had to match 6 players in the correct order for most popular outfielder from a pool of professional players numbered 1 through 49 , how many possibilities are there? Answered by Penny Nom. 





The sides of a parallelogram 
20090317 

From Sami: If ABCD is a parallelogram, prove that line AB is congruent to line CD. Clearly state your reasons and conjectures. Answered by Penny Nom. 





Cubic feet gas to grams of gas 
20090211 

From tim: I was trying to convert cubic feet gas to grams of gas. Is there a formula to complete this task? Answered by Robert Dawson. 





Will Juanita be late for class? 
20090128 

From safdar: juanita bumps into tory in the hallway between period 1 and 2,there is a 45% chance that she will be late for class.if she does not bump into tory, she will make it to class on time. there is a 25% chance that juanita will bump into tory. what is the probability that she will be late on any given day. be sure to introduce your events for this question and show the appropriate formula given the events. Answered by Penny Nom. 





The area of a triangle 
20090125 

From black: Explain how the formula for the area of a triangle can be determined by using the formula for the area of a parallelogram. Answered by Penny Nom. 





Converting grams to milliliters 
20090104 

From Faiza: I was looking for how to convert grams into mL and I read on this site
to convert one to the other you need to know what substance you are measuring.
so if I am measuring sugar or any of the baking ingredient like flour how do
I convert them from grams to mL is there a simple method I can use to do that? Answered by Penny Nom. 





650g+2kg+195g=how many kg 
20081211 

From christian: 650g+2kg+195g=how many kg Answered by Penny. 





A quadrilateral with two pairs of congruent sides 
20081210 

From nicole: what is the name of a figure that has 2 sides that measure 25 feet each and 2 sides that measure 10 feet each? Answered by Robert Dawson. 





A quadrilateral with exactly 1 pair of parallel sides and no congruent sides 
20081210 

From alie: a quadrilateral with exactly 1 pair of parallel sides and no congruent sides is what? Answered by Robert Dawson. 





Symmetries of a parallelogram 
20081124 

From anisha: how many lines of symmetry does a parallelogram have. A square and a rect are a
parallelogram too. so it is confusing?? pls help Answered by Walter Whiteley. 





Choosing light bulbs from a box 
20081114 

From Annie: A box of light bulbs contains 3 bulbs, two bulbs are defective.
What is the probability of choosing a nondefective bulb and a defective bulb in 2 draws?
What is the probability of choosing 3 defective bulbs followed by a non defective bulb?
What is the probability of choosing first 2 non defective bulbs followed by a defective bulb? Answered by Penny Nom. 





An Euler diagram and a logic argument 
20080918 

From Regina: Use a Euler diagram to determine whether the following argument is valid or invalid.
No wizard can yodel
All lizards can yodel
No wizard is a lizard Answered by Penny Nom. 





How many ml are in 40 grams? 
20080909 

From Nancy: I need to know how many ml are in 40 grams. So what is the base 1ml= how may grams Answered by Harley Weston. 





Reading a Histogram 
20080905 

From Bea: From a histogram only, can you find the frequency per each increment of an interval? Answered by Janice Cotcher. 





Microwave ovens and probability 
20080904 

From Vi: A microwave oven manufacturer claims that only 10% of the ovens it makes will need repair in the first year. Suppose three recent customers are independently chosen.
a. If the manufacturer is correct, what is the probability that at least two of the three ovens will need repair in the first year?
b. If at least two of the three customers' ovens need repair in the first year, what inference may be made about the manufacturer's claim? Answered by Harley Weston. 





A hexagon has 3 parallelograms 
20080721 

From Stephanie: A hexagon has 3 parallelograms but I am unsure of how to cut a hexagon into 3 parallelograms. Can you show me what this would look like? Answered by Harley Weston. 





How many pounds in 300 grams? 
20080624 

From Renelda: How many pounds in 300 grams? Can you send the formula? Thanks Answered by Penny Nom. 





Two forces acting on a body 
20080621 

From Rita: Before answering the question below, what exactly is, in basic words, resultant force?
QUESTION:
Two forces of 50 and 68 pounds act on a body to produce a resultant force of 70 pounds.
Find, to the nearest 10 minutes or nearest tenth of a degree, the angle formed between the resultant force and the smaller force. Answered by Harley Weston. 





The angles of a parallelogram 
20080611 

From light: ABCD is a parallelogram. If angle A. = (4x=17)degrees and angle B. = (3x5)degrees , what is angle c? Answered by Penny Nom. 





All wiffs are miffs and all miffs are kiffs. 
20080608 

From Allison: All wiffs are miffs. all miffs are kiffs. There are 25 wiffs. There are 76 kiffs. 33 kiffs are not miffs. How many miffs are not wiffs? Answered by Penny Nom. 





Naming a figure 
20080424 

From P.: What is the name of a figure that has 2 sides that measure
25 feet each and 2 sides that measure 10 feet each? Answered by Penny Nom. 





Ounces and grams 
20080402 

From Rakesh: 7.2 oz per sq. yard equals ? __ grams per sq. meter
How I can measure the weight of a Jeans fabric (in oz)? And what is the rellation between grams and oz? Answered by Penny Nom. 





The distance between the sides of a parallelogram 
20080330 

From jhon: Calculate the perpendicular distance between AB and DC of a parallelogram. Note: AB and DC are the sides of the parallelogram. Answered by Penny Nom. 





Drawing blocks from a box 
20080211 

From Inez: A box contains 3 red blocks and 1 green block. A block is chosen without looking and not put back. Then another block is chosen. What are the possible outcomes? Answered by Penny Nom. 





The interior angles of a parallelogram 
20080129 

From amber: the measure of one interior angle of a parallelogram is 42 degrees more than twice the measure of another angle. Find the measure of each angle. Answered by Penny Nom. 





The interior angles of a parallelogram 
20080128 

From steffie: How do you calculate the interior angle sof a parallelogram? Answered by Penny Nom. 





A parallelogram and a rhombus 
20080122 

From miguel: i have a problem proving a parallelogram a rhombus.. if a diagonal of a parallelogram bisects an angle
of the parallelogram , then its a rhombus
prove Answered by Stephen La Rocque and Walter Whiteley. 





Conditional probability 
20080114 

From Sara: Hello!
Ian has a photocopier in his office. If the photocopier is working on a certain
day then the probability that it will be working the next day is 0.9.
If the photocopier is not working on a certain day then the probability that
it will not be working the next day is 0.3.
The photocopier is not working on Monday.
(a) Calculate the probability that it will be working on Tuesday and Wednesday.
(b) Calculate the probability that it will not be working on Wednesday.
Could you please draw a tree diagram for this problem. Answered by Penny Nom. 





Forces on an inclined plane 
20080110 

From Ron: A body that weighs 540lbs is caused to slide up an inclined plane with a uniform velocity by a force that acts parallel to the plane. For each foot of horizontal distance, there is a vertical rise of 2in. If the coefficient of sliding friction is 0.16, what force is required to move the body? Answered by Stephen La Rocque. 





Converting grams of hair spray into milliliters 
20071202 

From komal: I am confused that i am converting 75grams of hair spray ( liquid) into ML? but i couldnt get the answer what is perfect answer for that please help me for this thing. Answered by Penny Nom. 





A thanksgiving day problem 
20071117 

From svetik: On Thanksgiving Day, a group of nutty professors dressed up as "turkeys" and participated in a local fundraising event. The event consisted of three types of races: the sprint, the relay, and the hurdles. One more “turkey” takes part in the hurdles only than the sprint only. The same number take part in the sprint and the hurdles as take part in the relay and the hurdles. Eleven of the “turkeys” taking some part in these three races do not do the relay. Five “turkeys” take part in the sprint and the relay and three enter all three races. There are four teams of four “turkeys” in the relay. And, one more “turkey” is running in both the relay and the sprint than in the hurdles only.
“Turkey” Coe turned and said to “Turkey” Kim, “How many ‘turkeys’ were taking some part in any of the three races?” The nuttiest math professor, “Turkey” Young, said “There were ________ ‘turkeys’ taking part in any of the three races.”
Fill in the blank!!! Answered by Penny Nom. 





EFGH x 4 = HGFE 
20071113 

From ROBIN: FIND THE NUMBERS THAT EACH LETTER STANDS FOR IN THE PROBLEM BELOW.
EFGH x 4 = HGFE Answered by Stephen La Rocque. 





How do i convert milliliters to grams for water and also for copper sulfate (CuSO4)? 
20071111 

From jenn: how do i convert milliliters to grams for
water and also for copper sulfate (CuSO4)? Answered by Harley Weston. 





What was the water level in the cylinder? 
20070911 

From glen: After a 5.63g sample of Wood's metal has been added to the water in a 10mL graduated cylinder, the new water level is 8.7mL. What was the water level in the cylinder before the sample was added? Answered by Stephen la Rocque. 





Which is more, 1.25 grams or 4.7 ml? 
20070822 

From jenni: Which is more? 1.25 grams or 4.7 ml Answered by Penny Nom. 





65 grams =_____?mg 
20070822 

From Quan: 65 grams = _____?mg Answered by Penny Nom. 





Proving a quadrilateral is a rectangle 
20070714 

From Sonja: I was having this discussion with another teacher and we need a third opinion. When you are trying to prove a quadrilateral is a rectangle which method should you use:
 Prove the shape is a parallelogram by doing slope 4 times by stating that parallel lines have equal slopes. Then proving a right angle by stating that perpendicular lines have negative reciprocal slopes.
 Doing the slope 4 times and stating that the shape is a rectangle because opposite sides are parallel because of equal slopes and it contains a right angle because of negative reciprocal slopes.
I guess the real question is do you have to first state that the shape is a parallelogram? Answered by Stephen La Rocque. 





The law of sines 
20070609 

From Felicia: A parallelogram has one side that is 12.0 cm and one angle that is 65°. The shorter diagonal is 25.0 cm. To the nearest tenth of a centimetre, how long is the other side of the parallelogram? Use the sine law. Answered by Penny Nom. 





Probability that a restaurant will succeed 
20070523 

From Cookie: You wish to open a new restaurant and are considering locations in Toronto and Hamilton, but only one location will actually become available. If it is built in Toronto, the restaurant stands an 80% chance of successfully surviving its first year. However, if it is built in Hamilton, its chance of survival falls to 65%. It is estimated that the chance of Hamilton being available is 60% and Toronto being available is 40%. Find the probability that the restaurant will :
a) survive its first year
b) be built in Toronto and survive its first year
c) be built in Hamilton, given that it survived its first year
d) not survive its first year, given that it is built in Toronto
Thanks Answered by Penny Nom. 





Converting yogurt 
20070521 

From Annie: I'm trying to follow a diet plan. The diet says I should have a 125ml tub of natural low fat bio yogurt. The only problem is, the yogurt pot lists its weight as 150g (with a large 'e' after it). Can you tell me how much of the yogurt pot I'm suppost to have please, or give me a conversion chart to change from g to ml for natural bio yogurt? Answered by Stephen La Rocque. 





Converting mass and volume of water 
20070510 

From Shian: Hello please help, I just can't seem to get the convertion thing and my mom tried to help but I still don't get it. How many grams does 1 milliliter of water weight? I was told 1g. How many grams does 0.1 liter of water weight? I was told 0.1g. Can you tell me if the answers given are correct with an explaination that I can understand? Thank you. Answered by Stephen La Rocque. 





Linear programming 
20070424 

From Sylvia: What is graphing linear programming? Answered by Penny Nom. 





Choosing a bicycle 
20070328 

From Jackie: A specific brand of bike comes in two frames, for males or females. Each frame comes in a choice of two colors, red and blue, and with a choice of three seats, soft, medium, and hard.
a) Use the counting principle to determine the number of different arrangements of bicycles that are possible.
b) Construct a tree diagram illustrating all the different arrangements of bicycles that are possible. c) List the sample space. Answered by Penny Nom. 





Grams to millilitres 
20070302 

From anton: I am trying to convert 28 grams of weight loss powder into mils Answered by Gabriel Potter. 





Grams/milliliters 
20070219 

From Keshia: If there are 27 grams of sugar in 240 mililiters, How many grams are in 100 mililiters? I have been trying to figure this question out for about an hour and I cannot seem to get it. Thank you for your help. Answered by Chris Fisher and Haley Ess. 





Centimeters to cubic meters and grams to kilograms 
20070214 

From Colleen: A box of balls measures 120cm by 20cm by 20cm and weighs 48 g. One thousand boxes = x cubic meters and weighs x kilograms. Also, one million boxes = x cubic metes and weighs x kilograms. One billion boxes = x cubic meters and weighs x kilograms. Solve for x. Answered by Stephen La Rocque. 





How many grams are in a 12 ounce coconut? 
20070208 

From Tristan: I have a problem where I need to know how many grams are in a 12 ounce coconut. Do I use "dry measure" with figuring out how many grams are in a ounce? And is that about 28 grams? Thanks. Answered by Penny Nom. 





The interior angles of a parallelogram 
20070207 

From jenniffeir: Can a parallelogram have two 45 degree angles and two 75 degree angles? Answered by Haley Ess. 





Grams and mls 
20070126 

From Larissa: Is there a formula to convert grams to mls..? Answered by Stephen La Rocque. 





The diagonals of a parallelogram are mutually bisecting 
20070121 

From Greta: I am having trouble proving that the diagonals of a parallelogram are mutually bisecting. Answered by Penny Nom. 





mls and grams 
20070119 

From JJ: If I have a 2000litre pool and need to put 2mg of chlorine per litre, how many mls do I need to add? Answered by Penny Nom. 





Two consecutive angles of a parallelogram 
20070117 

From Veronica: The measures of two consecutive angles of a parallelogram are in the ratio 9:11. Find the measure of each angle. Answered by Penny Nom. 





I want to convert milliliters into grams. 
20061214 

From Kenchotenzin : I want to convert milliliters into grams. Answered by Penny Nom. 





ml to grams 
20061111 

From Lisa: We have 900mL and you have to multiply by 1.18 grams do you just multiply and get 1062 grams or am I missing a step? Answered by Stephen La Rocque. 





An angle in a parallelogram 
20060813 

From Sam: Parallelogram ABCD has diagonal AC equal in length to side AB. CD is produced to E so that D is between E and C. If angle BAC =30 degrees find the size of angle ADE. Answered by Stephen La Rocque. 





Grams and milliliters 
20060727 

From Poh: We would like to know the conversion of 1 gm of cream/powder to ml. Answered by Stephen La Rocque and Penny Nom. 





Ounces of water to grams 
20060716 

From Liza: How many grams is in 10 ounces? I'm asking this question because i just bought a sea monkey and it says add 10 ounces of water and I don't know what that means. I have asked my parents but neither of them know. Answered by Stephen La Rocque. 





A person is given 3 true or false questions 
20060511 

From Larry: A person is given 3 true or false questions. They have no idea of the answers. What is the probability of the person getting them all correct? Could you show me a tree for this. Answered by Penny Nom. 





The area of a parallelogram 
20060312 

From Shayne: Is there a method of finding the area of a trapezium or/and parallelogram even if the height is not given? Could you also explain how to find the height? Answered by Penny Nom. 





Brokenline graphs and histograms 
20060216 

From George:
1. What is the main difference between a brokenline graph and a histogram? Both represent continuous variables.
2. What is the correct way to read a multiplication array: xaxis first and then yaxis, other way around or it doesn't matter?
Answered by Penny Nom. 





Milliliters to grams 
20051229 

From Kaitlyn: If I'm using baking soda, how do I convert milliliters to grams? Answered by Harley Weston. 





Brown hair and hazel eyes 
20050918 

From Julee: There are 28 students in a class. 15 have brown hair, 17 have hazel eyes, and 10 have both. How many students have neither brown hair or hazel eyes? Answered by Penny Nom. 





Converting from grams to milliliters 
20050915 

From A student: What if you don't know the liquid that you are converting from grams to milliliters? Answered by Penny Nom. 





Grams per liter 
20050220 

From A student: A litre and a half of water has 0.045 grams of herbicide added for spraying roses. How many grams of herbicide per litre is this? Answered by Penny Nom. 





Conversion of a recipe 
20050206 

From Peg:
A Hungarian friend gave me an old, old family recipe and it calls for:
20 dg. sugar
15 dg. filbert
I can't find a conversion table anywhere that explains how to get ounces from "dg." Do you know what the equivalent would be in ounces of dry measurement?
Answered by Harley Weston. 





1/4 tsp salt = ??? grams 
20041116 

From Julie: if i have 1/4 teaspoon of salt how many grams does that equal Answered by Penny Nom. 





Tennis balls and probability 
20041101 

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. 





Grams to milliliters 
20040925 

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 parallelogram 
20040730 

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 = 6x5 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. 





A new baby 
20040314 

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. 





Selecting balls from a golf bag 
20040221 

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. 





Grams and Milliliters 
20040217 

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. 





Probabilities and olivies 
20040214 

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. 





A problem with sets 
20040120 

From Jason:
Given that the universal set S is the set of all sports fans, and
F={xx is a football fan}
B={xx is a basketball fan}
H={xx 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. 





The area of a parallelogram 
20030406 

From A student: Find the area of the parallelogram with vertices (0,0),(7,2),(10,7),(3,5) Answered by Penny Nom. 





Can a square be a rhombus? 
20030304 

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. 





Can a square be considered a rectangle? 
20030227 

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. 





I have three circles... 
20030130 

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. 





Tree diagrams 
20021012 

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. 





Baseball, basketball and football 
20021008 

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. 





Parallelograms 
20020821 

From Moorthy: 11 parallel lines are intersected by another 9 parallel lines.Then how many parallelograms are formed? Answered by Walter Whiteley. 





Linear programming 
20020527 

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. 





Conditional probability 
20020519 

From Manny: In a certain school, it is known that 80% of the students use the internet for school projects, 60% use email on a regular basis, and 90% use the internet for school projects or for email on a regular basis. a student from this school is selected at random Determine thge probability that the student used email, 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. 





Conversion of units 
20020429 

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 health club 
20011125 

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. 





Applied geometry 
20011102 

From Jenny: Where can I find some handson 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. 





Milliters and grams 
20010920 

From Bettyjo: 500 ml is what in grams Answered by Pnny Nom. 





300 pounds 
20010912 

From Cassie: HOW MANY KILOS IS IN 300 POUNDS? Answered by Penny Nom. 





Genealogy 
20010322 

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 250300 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. 





How can you prove a quadrilateral to be a parallelogram? 
20010316 

From Joy: How can you prove a quadrilateral to be a parallelogram? Answered by Walter Whiteley. 





Vitamins A and B 
20010114 

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. 





Derfs, Enajs and Sivads 
20010107 

From John and Norman: All Derfs are Enajs. Onethird 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. 





False Positives 
20001029 

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 twotier 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. 





Pillows and Cushions 
20000927 

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. 





How many grams are in 1 ounce? 
20000404 

From Kathy G: How many grams are in 1 ounce? Answered by Penny Nom. 





Careers after a math degree 
20000331 

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. 





Congruent parts of congruent figures 
20000310 

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. 





100% on two tests 
20000201 

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. 





Bar graphs and histograms 
20000111 

From Raeluck: What is the difference between a bar graph and a histogram? Answered by Harley Weston. 





Linear programming and optimization 
19990409 

From Shams: What is Linear programming and optimization? Answered by Jack LeSage and Penny Nom. 





Converting Metric Measurements 
19990408 

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 
19990408 

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. 





Metric Conversion 
19990307 

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. 





Circumference and Area 
19990216 

From Natalie: finding the circumference of a circle? formula finding the area of a parallelogram? formula
Answered by Penny Nom. 





A Puzzle 
19981027 

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. 





Operations Research 
19981008 

From Lisa Barrett: What is the history of operations research and the study of linear programming? Answered by Judi McDonald. 





Isosceles trapezoid formula 
19980512 

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. 





Tangrams 
19980224 

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. 





Diagramming Powers 
19971015 

From David Fill: I am a teacher in Massachusettes. We have been diagramming numbers such as two to the third (a 3D 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. 





Histograms. 
19970926 

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. 





Diagonals in a polygon 
19960618 

From Steven: How many diagonals are there in a polygon? Answered by Denis Hanson. 





Léo a programmé sa tortue 
20100215 

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. 





programme de tracé 
20041021 

From jeanyves: pourriez vous me donner la définition de: qu'es ce qu'un "programme de tracé" Answered by Claude Tardif. 

