







Mathematical ideas in everyday life 
20171108 

From Ricita: Mathematical ideas to solve various problems of our everyday life ,environment
related problems. Answered by Penny Nom. 





3rd Grade math problem 
20170530 

From Angela: Following is a problem from my 3rd grader's homework assignment:
Solve. Draw a diagram to represent the situation.
Rachel has 20 oneinch beads. She wants to use all of them to make a square picture frame. What will be the length of each side?
Find Perimeter, Area, and Side Length Answered by Penny Nom. 





Selling price and markup 
20170424 

From Julie: What would the cost of an item be, if the sell price was $50 and the markup 48% Answered by Penny Nom. 





How much does the fish weigh? 
20170308 

From Jeri: Fish is caught that weighs 5 pounds plus half its weight. How much does the fish weigh? Answered by Penny Nom. 





Volume of liquid remaining in a tilted cylinder 
20161108 

From Brian: I am trying to determine the amount of a liquid remaining in a 55 gallon drum when it is tilted at 45 degrees and the liquid level is low enough so that the liquid does not completely cover the bottom of the drum.
Your help is greatly appreciated. Answered by Harley Weston. 





A barn roof 
20160529 

From Joe: Is it possible to build a barn roof (irregular pentagon?) with a 12' base and the other 4 sides 4' each? Thanks. Answered by Penny Nom. 





The volume of a truncated rectangular pyramidal pond 
20160513 

From Paul: How do you calculate a partially filled truncated rectangular pyramid if you always know the bottom rectangle, the maximum height top rectangle perimeter, but have a varying height. Similar to filling up a pond you know the current height and dimensions at the max rectangle how do you calculate it half full i.e. 10x30 outside perimeter with a 2x8 base and a max height of 6ft how do you calculate it at 3ft without remeasuring the top perimeter.
Thanks,
Paul Answered by Harley Weston. 





A deck that is half an ellipse 
20160228 

From Steve: On your website, I was reading a question and your response from a girl named Angela in which you provided a formula by which her father, a welder, could figure out points on an arc corresponding to equal 3' intervals on a 30' chord where the vertex was 1' off the chord. Is there an equivalent formula when working with an ellipse? I suspect this change will make the calculations significantly more complex. I am building a deck that is half an oval, and would like to be able to mark out the perimeter by measuring the distance from regular intervals on the primary access to a corresponding point on the perimeter. I will then connect the points on the perimeter and cut a reasonably smooth arc. The length of the primary access will be 22' and width of the deck at the vertex is 9'. I would like to be able to know the distance from the primary axis to a point on the perimeter at equal intervals of 6" along the primary axis. Can you help? Answered by Penny Nom. 





Shooting a ball at a target 
20160216 

From Thys: Hi
I have a problem with the formula that i use .(for programming)
I have looked all over the web to find a solution but no luck.
I have a cannon that shoots a ball at a target
I use this formula to calculate what my initial velocity must be to hit the target
at a angle of 30 degrees and a distance of 15m (the cannon and target position is known)
It works perfectly if both is at same height but if one is higher or lower it miss.
In an example I am working with the range is 30m, the angle is 45 degrees and the target is 10m higher than my position.
Please help
Formula = V0 = √RG / Sin(2α) Answered by Harley Weston. 





Roof Square footage 
20151111 

From Todd:
Question from Todd:
Good Day.
I have to figure out the square footage of a quonset style roof that's not playing by the rules The building dimensions (rectangular) are 63'x135' the height of the roof is 9.25'. It not an entire Quonset, It's that style of roof,(curved). There are concrete block walls 10' up to the metal roof.
Thank you!
Todd Answered by Harley Weston. 





The diameter and circumference of a circle 
20150901 

From Tracey: Hello,
I own a custom workroom, I am figuring out fabric quantities or an estimate. When
at the job site, I forgot to measure the diameter of the semi circle shape that I have to
make a cushion for!!!
If the circumference of the semi circle is 165" what would the diameter be, maybe half
this measurement????
I appreciate any help...I basically need the width from left to right to see if I can fit
the cushion on one width of fabric that is 52" wide! Answered by Penny Nom. 





Filling a pool with dirt 
20150501 

From Mike: I have a hole which a 24 ft pool in it is 10" deep in the the centre and goes to 1" inch at the edge want to fill it in with dirt how many yards of dirt would I need to fill it in Answered by Penny Nom. 





A wireless fence 
20150418 

From Dave: I'm buying a wireless fence to keep my pet in my yard. It has a half acre range. In a straight line how far would that be? Answered by Penny Nom. 





A fishfinder 
20150313 

From Dave: I have a fishfinder that has a 20 degree cone on bottom of boat going to the bottom of the lake.
How do I know the size of base diameter of the cone on the lake bottom depending on depth...
such as 10 feet deep, for example? Answered by Penny Nom. 





The length of a ramp 
20150305 

From Jaylynn: Hi, I've been trying to figure out how long my ramp would have to be in order to reach a height of 3.5 feet at a 30 degree angle for a sugar glider enclosure? Answered by Penny Nom. 





Bricks around a fire pit 
20150305 

From Jayson: I have a round fire pit. It measures 25 inches in diameter. I have 12 inch long square bricks to go around it . My question is what degree do I cut the ends of these bricks to make them fit around this circle? The brick dimensions are 12"Lx6"Wx4"D. Answered by Harley Weston. 





Stopping distance 
20150211 

From Audrey: A Harley Davidson motor cycle weighing 650 lbs with a rider weighing 175 bs
was going 40 miles per hour. He had to make a sudden stop . Slammed on brakes. How long a distance for him to stop? Answered by Penny Nom. 





Math in the universe 
20150121 

From GA: I want to find out examples in universe for this equation:
sin(x)/cos(x)=1 or tan(x)=1. I know the mathematical answer of pie/4 or 45 degree angle.
What I need to know is to find examples of this. I found an example in construction, for example, which is the shape of attic in the house.
I want to find examples in universe like in solar system, in quasars or jets coming out of them, in galaxies, in stars, in black holes, etc
Do you know of any such examples? Answered by Robert Dawson. 





Logarithms 
20140828 

From effaryna: how logarithms is applied in everyday life? Answered by Penny Nom. 





Cutting a round cake so that it doesn't dry out 
20140826 

From James: I'm wondering if there's a simple way to calculate the area between two parallel chords of a circle equidistant from its diameter, or if I have the area, to find the distance between the two chords.
Here's my "problem". You may have heard of the way of cutting a round cake so that it doesn't dry out  make two parallel cuts (chords) the length of the cake, take the middle piece, then push the two pieces together.
So I know the area of a 12" cake, and I want say, exactly an eighth of the cake. How wide do I cut the centre piece?
Now to get even more difficult, the next day I want another eighth from the centre. How wide do I cut the next pieces, and so on...?
Thanks,
James Answered by Harley Weston. 





Quarters 
20140704 

From kamal: how many quarters in the sum of 8 and 12 ? Answered by Penny Nom. 





Covering a 12 inch by 12 inch square hole 
20140702 

From Patricia: I am putting in a new bathroom fan. I am wondering if a new light with a 15 inch diameter will cover the existing square hole which is 12 by 12 inches? If the existing hole is 11 1/2 by 11 1/2 inches?
Also, if the 15 inch diameter does not cover the 12 by 12 hole, what size diameter would?
Thank you. Answered by Penny Nom. 





An oval pool 
20140621 

From steve: I have a 16' x 28' oval pool that is buried 24" deep inground. The dig site is dug
2' wider all the way around the pool. I need to back fill this area with stone. I want to fill this area with 6 to 8"
of stone. How many tons of stone will this take?
Thanks you
Steve Answered by Penny Nom. 





How do we use logarithms in our daily life 
20140601 

From ss: how do we use logarithms in our dailylife Answered by Penny Nom. 





An octagonal pad 
20140425 

From George: Hi,
I need to pour a cement pad in the shape of an octagon that allows
for 12" of clearance around the tank I will be putting on it.
The tank has a radius of 16'. Answered by Penny Nom. 





The cost before the sales tax 
20140413 

From Juanda: Hello,
I know the customer cost with tax and I know the sales tax.
How do I find out the customer cost prior to the added sales tax?
Thank you Answered by Penny Nom. 





A sand trench around a pool 
20140413 

From steve: How sand is needed to back fill a trench around a 24ft dia. pool that is 26" deep by 2ft wide. Making the outside dia. 26ft.
Thank You Answered by Penny Nom. 





Decimals,fractions and percentages 
20140411 

From Frances: Ask an expert to find out their real life usage of your topic... that is the question.
meaning what is your real life usage of using decimals,fractions and percentages.
This is all part of my math assignment to ask an expert real life usage... so please
reply back as soon as possible Answered by Penny Nom. 





Cutting a hexagon from a disk 
20140405 

From Paul: I am a machinist and sometimes need to make a hex from
round material.
If I know the distance of the flat sides opposite one another
of my hex, how can I calculate the size of material I need to turn
to give me the right diameter to finish the part with six sides? Answered by Penny Nom. 





The area of a 5 sided lot 
20140315 

From Michael: Question from michael:
This lot is in feet. 59x154x109x188x137 per the plot plan Answered by Harley Weston. 





Rolls of window film 
20140214 

From Travis: This question is probably close to the same question as "roll of paper"
We have Rolls of Window Film that we are trying to figure out an equation for a spreadsheet that we can use to "inventory" our window film.
We use a caliper tool to measure the thickness of the roll in millimeters.
the core thickness = 1.90mm
Full Roll thickness(including core) = 9.08mm to 9.12mm
Film thickness = 0.06
Full Roll of Film is supposed to average 1200" of film
What equation could we use to get the approximate inches left remaining on the roll if we measured the roll including the core with the Caliper tool in Millimeters? Answered by Harley Weston. 





Conics 
20140201 

From Kassidy: Hey, I have searched through all the questions about conics and how
people use them in the real world, but none of them were very specific
on how they are applied and the process, why it's so important etc.
I have a project due asking these questions and it's been very difficult
finding the right answer, if you could name jobs, how they are use and
specifically applied that would be greatly appreciated. Answered by Penny Nom. 





The fourth side of a quadrilateral 
20140123 

From joanna: left vertical measurement 2560mm
right vertical measurement 1850mm
base horizontal measurement 1750mm
question  what will the 4th measurement be please.
using a scale drawing I make it approx 1900mm but require an accurate measurement
regards
Joanna Answered by Penny Nom. 





25% profit 
20140102 

From Finn: Hello,
The question is all about buyandsell business.
Problem:
Pencil  $6 for whole sale price
$8 if I sell the item
How do I get the 25% profit? (you can change the whole sale price and the retail price[if i sell the item])
if I buy the pencil at 24 pieces and sell it at 24 pieces. Answered by Penny Nom. 





conical lamp stand/staved wood 
20131207 

From Henry: need to make lamp stand that is wooden staved; need it to be 25 inches at bottom and 10 inches at top; need to know angles for staves to be cut; the lamp stand will be rounded on a lathe and will be 40 inches tall John Lucas built one and it is pictured on his web page. thank you for any help/direction; I checked out the answered for cone shaped objects on your page but didn't find what I could use. thanks again. Henrywoodturner, parent teacher student . . . . . Answered by Harley Weston. 





A square inscribed in a circle 
20131014 

From Jenn: Hello! I am about to buy a 7'9" round rug, but I want to have it cut down into a square. What's the largest square I can obtain from this? Thank you! Answered by Penny Nom. 





Proportional rates 
20131010 

From Varsha: A province's Ministry of Social services has found that both the number of people needing social assistance and the province's total expenditures on social assistance are proportional to the rate of unemployment. Last August when the provincial unemployment rate was 8.4 %, the province provided assistance to 89,300 individuals at a total cost of 4107.4 million. The forecast unemployment rate for next August is 7.9%. How many people can the province expect to need social assistance next August? What amount should the province budget for social assistance in August? Answered by Penny Nom. 





GST and PST 
20130722 

From Bev: Total sales revenues are 116391.38 this amount includes 5% GST and 80% of this amount includes a 7% provincial tax. The other 20% is PST exempt. GST is included in all. How do I figure the PST I owe? Answered by Penny Nom. 





Dirt to fill a pool 
20130713 

From Neil: I had a 24 foot diameter pool. The perimeter of it was at ground
level. The pool sloped 1 foot deeper to the middle. In other
words "a 1 ft. dish. How many cubic yards of dirt do I need to
fill this hole? Answered by Penny Nom. 





Scheduling a 12 person fishing 
20130709 

From Don: Greetings Math Central!
I searched the index, but could not find a similar quandary.
Here's my predicament:
I am seeking help in scheduling a 12 person fishing outing.
We have four boats.
I would like to schedule three fishermen to a boat.
We fish 2 1/2 days, split into morning and afternoon sessions.
Thursday afternoon, Friday morning, Friday afternoon, Saturday morning, and
Saturday afternoon
We switch boats after lunch, with each fisherman moving to a different boat,
with different partners.
I would like to have each fisherman fish with as many others in the group as
possible, with a minimum of partner duplication.
I would like to have each fisherman fish in all of the four different boats
over the course of the trip at least once.
Would you please suggest a boat / fishing partner schedule that fits my
parameters as closely as possible.
Thank you!
Don Answered by Victoria West. 





A kennel for a beagle 
20130603 

From david: Hi, I'm building some beagle kennels and I am in need of help with an angle problem. I need to place a roof on my kennel with a drop of 2inches across 3ft 10inches. the posts on the right side will be 5ft and the post on the left will be 4ft 10in. the posts are 4x4 and the space to be covered is 3ft 10in from the outside of the 4x4. Please help, thanks. Answered by Penny Nom. 





How do i reverse this formula? 
20130420 

From MK: I have 22,000,000 worth of gold and wants to want to resell the gold back with a profit.
Each transaction of gold will have a transaction fee of 15%, so if i resell the gold back at 22,000,000, I will only get back 18,700,000 after 15% transaction cut.
The current formula is X15%X = Y where X = 22,000,000 and Y = 18,700,000
Will u be able to come up with a new formula if we don't know the value of X but we know the value of Y
Something like this X15%X = 22,000,000.
How do i reverse this formula to find the value of X
Thanks Answered by Penny Nom. 





A gravel pile in the shape of a triangular pyramid 
20130404 

From Casey: Hello
Right now I am stuck and I feel embarrassed because I feel like the answer is so easy I should know it.
I am working on a project and need to find a volume of gravel it will take to occupy this triangular prism like area. I am not sure what formulas I should use whether it be that for the volume of a pyramid or something more complex? Basically it forms a right triangle at one side then from there all points slope to one singular point about 10412mm away.
I am attaching a picture drawn up in paint with the actual dimensions to clear up any confusion.
Thank you for any help.
Casey Answered by Penny Nom. 





Question 
20130404 

From Casey: Hello
Right now I am stuck and I feel embarrassed because I feel like the answer is so easy I should know it.
I am working on a project and need to find a volume of gravel it will take to occupy this triangular prism like area. I am not sure what formulas I should use whether it be that for the volume of a pyramid or something more complex? Basically it forms a right triangle at one side then from there all points slope to one singular point about 10412mm away.
I am attaching a picture drawn up in paint with the actual dimensions to clear up any confusion.
Thank you for any help.
Casey Answered by Penny Nom. 





What is the subtotal & GST? 
20130304 

From REBECCA: Hi, I have a total of $300.
What is the subtotal & GST?
How do I work backwards? Answered by Penny Nom. 





Milling round stock to square stock 
20121217 

From Bryan: Question from Bryan:
I want to know what the smallest diameter round is that will make a 31/4" square? Is there a formula for that? I am milling round stock into square.
Thank you. Answered by Harley Weston. 





Practical uses of trigonometry 
20121111 

From Michael: Where can I find books or information on real life function of sine and cosine? Answered by Penny Nom. 





A mathematical expression with the answer 7 
20121110 

From emily: hey um i need to find and problem that fallows bedmas that has one division one multiplication and one sub and one add and one brackets and one exponents that has the answer of number 7 Answered by Penny Nom. 





A label to cover a plastic cup 
20121023 

From Kevin: I'm trying to make a label to cover the entire outer area or a plastic cup. I know there must be a way to figure out the dimensions needed, but I can't seem to figure it out. The circumference of the bottom of the cup is 21.4cm and the circumference at the top of the cup is 29.8cm. The cup is 14.5cm tall. What should the height of the arc from the plane connecting the two ends of the 21.4cm arc. I attached a diagram where x is the value I'm looking for. I'm guessing there is some simple relationship between the length of a line and the arc needed to turn that line into a perfect circle, but I don't know what it is. Can you figure this out and share it with me? Thanks.
Kevin Answered by Penny Nom. 





A tank with an inner walled compartment 
20121012 

From don: I have a tank 20 feet diameter, 19' 8" tall with an inner walled compartment that has a 7' 6" radius arc with in the tank. I need to figure out the volume of the inner area and the volume of the larger area. Answered by Harley Weston. 





GST in New Zealand 
20121010 

From Colleen: I work out my claimable gst each month but need to know the total sales or purchases amounts for filling in my six monthly paper work. How do I do that. I tried doing the opposite of calculating the gst i.e. x3 and /23 but it is slightly different to my total. Answered by Penny Nom. 





A profit of 35% 
20120907 

From Jack: If a product cost me $10.00 and I want a profit of 35% what is my sell price? How do I figure the sale price to make a 35% profit on the sale? Answered by Penny Nom. 





The volume of fluid in a tank 
20120906 

From Dave: I have vertical round flat bottom tanks of various dimensions. It is easy to find total volume but I would like to know how to figure out the coversion factor to go from how many centimeters of liquid is in the tank to the number of total cubic meters of volume. So if my float gauge on the tank says there is 50 cm of fluid in the tank, how many cubic meter of total volume is there? Answered by Harley Weston. 





A container of split peas 
20120906 

From Laurie: I have a container that is 471 square inches (length*width) and is 2.3 inches high. I want to cover the bottom with 1/2 inch of split peas, in order to anchor escort cards (place cards) for a wedding. How many pounds of split peas do I need to cover the area to a height of 1/2 inch? Thanks Answered by Penny Nom. 





A schedule for 6 teams and 37 games 
20120829 

From Giovanni: Hello, i try to prepare a schedules for 6 teams, and every teams will play 37 games before the playoff. How to make a schedules? thanks Answered by Victoria West. 





Making a wind sock 
20120828 

From John: I am trying to build a wind sock and need to be able to lay the shape
out on cloth. I need the wind sock front opening (diameter) to be
3 1/2" and the rear opening diameter to be 1". The windsock needs
to be 9 1/2" long. I tried using the example of the person trying to
make a crayfish trap but got confused and could not figure out my
numbers. Any help would be greatly appreciated.
Thanks
John Answered by Penny Nom. 





Golf for 16 in 7 rounds 
20120816 

From Elizabeth: Hello,
I am trying to sort out golfing for 16 guys for 7 rounds. However the twist is that the teams are broken down into 8 old boys vs. 8 young boys. Ideally, each of the players would only play each other once within their own team and then twice within all of the matches. Is that possible? Thanks for your help, my brain is hurting! Answered by Victoria West. 





A tapestry rod on a curved wall 
20120814 

From Marlyn: I have a curved wall with a radius of 6'. I am trying to have a 36" rod made to hang a tapestry and need to figure out the degree measure of the arc.
Can you help me please? Answered by Penny Nom. 





A 10 inch circle using 2x4s 
20120519 

From Ralph: I want to form a 10" circle with 4"high pieces of 2 x4's. If each 2x4 piece sit next to each other,What degree would I have to cut
each side of the 2x4's, and how many would I need to form a 10 inch circle. I know there is a formula for this out there somewhere. Answered by Harley Weston. 





Measuring the liquid in a horizontal tank 
20120228 

From Philip: I have a steel gas tank that is 3' dia X 5' length. The total volume is 1000 litres.
But how much is left when I use a stick and measure 6" from the bottom or 12" or 24" ??
Is there a formula to use for this task?
Thanks. Answered by Harley Weston. 





Building a tipi 
20120129 

From Lacy: Hi there!
We are building a tipi for our children. We want to build a large one about 15ft tall with a base of about 15 feet diameter. I am trying to figure out how much canvas we need to accomplish this. I graduated about 20 years ago and am struggling. Please help if you can. Answered by Penny Nom. 





The volume of a dugout 
20120128 

From Jan: is there a formula for calculating the cubic yardage removed from a dugout
for example that is forty feet wide by one hundred and twenty feet long by
twelve feet deep with a three to one slope? It is the slope that makes it a
little tricky. Thank you. Answered by Penny Nom. 





Uses of logarithms 
20111109 

From BEA: what is the use of logarithmic functions in real life or daily life? Answered by Penny Nom. 





Building a custom range hood 
20111008 

From Bill: I'm building a custom range hood for a customer with special order material that matches
their newly installed cabinets and I need it to be perfect. The hood is basically a pyramid
but the 4th side is the flat wall at the back and a flat, rectangular top. I need to calculate
the bevel and miter of the three sides but I never was very good with geometry functions
(although I am fairly good with other math fields). I either need the calculations from you
at least (shudder) a formula or set of formulas so that I can calculate them myself. Answered by Harley Weston. 





Geometry Related Careers 
20110901 

From Richard: Good morning,
I am hoping to find a list of careers that would relate to geometric constructions and tessellations.
I have searched the internet some and some of the sites I have found are a bit questionable or dated. Are there sites that Math Central would recommend?
I could not find anything when I did a search on the site.
Thanks in advance,
RVD Answered by Walter Whiteley. 





A stained glass lamp 
20110725 

From Guy: Like Kay, I also work in stained glass, but in 3dimensions. I am
frequently asked to replicate lamp shades in stained glass where the
diameter of the top is different (narrower) from the diameter of the
bottom (which is wider). Some people want 5, 6, 7, 8, 10, 12, 16, ,,,
nsided shades. Is there a formula I can use to determine the width
of the sides using the angle, if I remember correctly, I think it's
called theta. In other words, is there a formula where I can plug
in the angle which describes the arc of the circle. For instance, if
someone asks for a 7 sided shade, plugging in 51.43 (360/7). I
could then use that to determine the width at the top and bottom
rings to create the appropriate trapezoids. I've visited a few sites
so the formula looks like its a function of sin & cos but they are
presented like proofs for teaching. Your site appears to want to
actually answer questions without making the inquirer feel stupid. Answered by Harley Weston. 





The height of a fluid in a horizontal tank 
20110724 

From jason: Same set up as many others, cylindrical tank on its side, but I am interested in defining the change in volume and/or fluid level as a function of time at a constant volumetric outflow. I plan on hooking a pump to the tank so "gpms' will be constant. I have a couple different sized tanks and pumps so I want a general equation. Thanks for your help. Answered by Harley Weston. 





The length of a belt around three pulleys 
20110518 

From Grant: I need to calculate the belt length around these pulleys, please can you
help or refer me?
Known variables
D  Large Pulley Diameter
d  Small Pulley Diameter
c  Center Distance between D and d
T  Tension Pulley Diameter
x  Horizontal Distance between T and d' Centers
y  Vertical Distance between T and d's Centers
I need to calculate the belt length around these pulleys.
Kind Regards,
Grant Answered by Harley Weston. 





How much gravel do I need to make it level? 
20110222 

From Robert: I have an area that is 55 feet long x 75 feet wide and goes from 0 to 13 inches deep. How much gravel do I need to make it level? Answered by Penny Nom. 





Calibrating a conical tank 
20110205 

From Bill: Hi, I have a round tank with tapered sides where I know the diameter at the top and bottom. Is there a formula I can use to calculate the volume by measuring from the bottom up the side (at the angle of the side) to any given point? Thanks, Bill Answered by Stephen La Rocque and Penny Nom. 





Daily life example of logarithms 
20110204 

From owais: what are the application or daily life example of logarithms? Answered by Harley Weston. 





A fence around a water tank 
20110201 

From Heath: I am building a fence around a water tank. the fence is to be in the shape of a normal octagon. The tank has a circumference of 57 ' 6''. I would like the fence to be 3 ft from the tank at the skinny point . How would I calculate(for the simple guy) where to set each of my 4x4 posts at the 8 corners. Any help would be greatly appreciated. Answered by Harley Weston. 





Mathematics and a musical dilemma 
20110119 

From rahul: how is mathematics applied in entertainment? Answered by Harley Weston. 





Exponential form 
20110102 

From jumana: find any five examples of exponential form from real life situation Answered by Penny Nom. 





An air duct in the form of a circular cylinder 
20101219 

From ed: an air duct in the form of a circular cylinder has a cross section if diameter 16 in. the distance between the bases is 20 ft and the elements are inclined at an angle of 50 degrees to the bases. find the amount of magnesia required to protect the duct with magnesia covering 1/2 in thick? tnx Answered by Stephen La Rocque. 





Sales as a function of advertising 
20101208 

From Adori: The sales S(in thousands if units) of a product after x hundred dollars is spent on advertising is given by S=10(1e^kx). Find S as a function of x if 2500 units are sold when $500 is spent on advertising. Answered by Penny Nom. 





A punchcode lock box 
20101129 

From Doug: I am a real estate agent that uses punchcode lock boxes on houses to store the keys. I need to crack the code on one of our boxes, so I need a list of the possible combinations.
Rules:
4 digit code
Numbers 09
Each number can only be used once
Order of the numbers does not matter.
With advice from this site, I have calculated that there should be 210 possibilities.
10x9x8x7 (5040) gives me the total number possibilities and 4x3x2x1 (24) gives me the total number of ways to arrange those numbers.
So if I divide the possibilities by the arrangement, I get 210. (5040 / 24 = 210) GREAT!!!
Now, how do I develop a list of those 210 combinations?
Thanks for your help. Answered by Robert Dawson. 





The slope of a hole 
20101028 

From William: What is the slope of a hole that is 7.4 mm in dia by .5mm in depth. Answered by Penny Nom. 





Mathematics and medicine 
20101013 

From Dixie: need equations used in medicine for medicine and intravenous administration Answered by Penny Nom. 





20% profit on the selling price 
20100924 

From ata: My cost is 100 and I want to make 20% profit on my selling price (not 20% of the cost). So, what should be calculation formula? Let's say my cost is 493.71 and I want to make 53.28% profit on the selling price; so how to determine the selling price? Answered by Penny Nom. 





A reverse PST calculation 
20100923 

From Manning: Hi, I'm a manufacturing contractor in Saskatoon. The way to calculate PST for us is using total contract amount x 70% then 5%.
For example, contract amount of $100 x 70% x 5% = $3.5 (PST). The subtotal is using contract amount + PST.
$100 + $3.50 = $103.50.
If you only know the subtotal is $103.50 including PST, how do you reverse calculation to get the contract amount?
Thank you very much for your help. Answered by Harley Weston. 





Constructing a tipi 
20100920 

From mike: we are thinking about making a lightweight tipi tent but we need to know what the angles and lengths of each side that we will need to cut. The height of the tipi wants to be about 2.2m span at the widest point wants to be about 3.2m we want to make it based upon a 6 sided(hexagon) shape thanks for your help Answered by Harley Weston. 





How are decimals used in every day life? 
20100901 

From Keith: how are deciminal used in every day life Answered by Tyler Wood. 





A spaceship playhouse 
20100726 

From Dave: I would like to build a spaceship playhouse for my grandson I want it to
be about 36" around and I want to use 5/4 decking boards that measure
5 1/2" wide how do I figure out how to lay out a base pattern to nail to
(what angle do I need to cut and how many boards will it take to go around
the circle. Answered by Penny Nom. 





The tonnage of some gravel 
20100722 

From Gregory: i have a road that is 8 miles long 20 feet wide and 4 inches deep what is the tonnage for gravel i would need Answered by Penny Nom. 





I need to learn to think mathematically 
20100720 

From Student: I need to learn to think mathematically, and like math while doing it, got any ideas, help. Answered by Walter Whiteley. 





Fibonacci and induction 
20100712 

From James: I'm trying to prove by induction that F(n) <= 2^(n1)
where f(1)=f(2)=1 and f(k)=f(k1)+f(k2) for k >=3 is the Fibonacci sequence Answered by Stephen La Rocque and Tyler Wood. 





An octagon shaped bench 
20100709 

From rob: i am trying to build a octagon shaped bench to fit inside a 69 inch round hot tub so that the tip of each point touches the edge of the circle where it will be fastened. Answered by Stephen La Rocque. 





A play tent 
20100628 

From Susan: Hi!!!
I am making a play tent as seen at the link below and need to figure out how to get the dimensions for the cone shape. The one shown has 4 different seams, but I guess I can get away with just one seam to sew it together (?) I need it to go over a hula hoop as that is what I am using for the round support at the top. My hula hoop is
35" in diameter from outside edge to outside edge. I would like the height of the teepee to be around 30" from the center to the peak.
Thanks so much, oh my gosh, I have been fretting for 2 days about this and my hair is about to fall out!!!!
Please contact me if you need any additional info.
~Susan
http://www.landofnod.com/family.aspx?c=52&f=4100 Answered by Penny Nom. 





Math in the workplace: nursing 
20100524 

From Taylor: How is math used in the workplace  Nurse Anesthetist? Answered by Penny Nom. 





The low leg height of a shutter 
20100520 

From brian: I work for a shutter company and am in need of a formula to figure
out what the low leg height would be if given the width of shutter,
the high point of arch top and the radius. example would be a 18" wide
shutter with a 80" high leg on the right side and a 30" radius. I would
need a way to figure what the low leg height (left side of shutter)
would be. Or if given width, low leg height and radius what the high
side would be? If any of this can be given in laymen's terms it would be
much appreciated.
Thanks,
Brian Answered by Harley Weston. 





Rolls of sod 
20100427 

From judy: My yard is 35 feet by 29 feet. I want to put sod on the entire yard.
The rolls of sod are 9 square feet. How many rolls of sod will I
to complete the job? Answered by Penny Nom. 





Tiles 
20100425 

From Pat: how many 6 inch tiles will I need to purchase for an area that is currently covered with 351 4 inch by 4 inch tiles.
Each box of 6 inch tiles states it contains 16 pieces and covers 4 square feet. Answered by Penny Nom. 





Commission 
20100424 

From TAHIR: I want to predetermine the amount of commission on sale of my product which will be the amount that I shall have to pay .
For example, the price is $ 600and commission 5% .
1) I calculate commission on 600 @ 5% = $ 30
When added $ 600 the retail price = $ 630
2) But on $ 630, 5% commission = $ 31.50
So we make a loss of $ 1.50 .
3) Again if we add this $ 1.50 to $ 630 the price = 631.50
But the commission when calculated does not tally
and we make a loss of $ 0.075.
Please let me know how to determine the commission beforehand so that it matches our accounts. Answered by Penny Nom. 





Vapor trails 
20100412 

From Frank: I'm not sure if this is a proper question to ask so if I have misdirected my question I apologize and no response is expected. I am trying to figure out a way to measure vapor trails from my back yard in Phoenix Arizona. If I used a compass and spread each point of the compass to the start and finish of the vapor trail I would have the angle of an isosceles triangle. The other two angles would be identical. The height of from the inverted base of the triangle to my standing spot on the ground would be about 35,000 feet. I'm thinking that there should be a way to figure out the length of the inverted base (vapor trail) but I'm devoid of mathematical skills and can't seem to figure out how to do this. Is it possible to figure out the length of a vapor trail using this method or do you have an easier way to accomplish the task?
Any help you could offer would be most appreciated.
Thanks....Frank Answered by Harley Weston. 





The area of a field of view 
20100407 

From Frank: I know we have a field of view of 90 degrees and the distance we can cover is 6 miles. What is the area we can cover/view?
A formula would be nice to have since the diameter or distance of the wedge area can change and the degree of the field of view can also change.
Thank you and I look forward to hearing from you.
Frank Answered by Penny Nom. 





A proof by induction 
20100325 

From SAMUEL: use mathematical induction to proof that each statement is true for every positve integer n
1/1.2+1/2.3+1/3.4+......1/n(n+1)=n/n+1 Answered by Robert Dawson. 





The nth derivative of x^(n1) log x 
20100310 

From shambodeb: This is a successive differentiation problem by Leibnitz theorem
If y = x^{n1} log x ; Proof nth derivative y^{(n)} = (n1)!/x Answered by Harley Weston. 





An irregular octagon 
20100309 

From Gayle: Question from Gayle:
I am building an irregular shaped octagon wooden box.
The measurements are 291/2 inches by 211/2 inches.
Sides are 12 inches.
It will be 36 inches high.
What would the cutting angles degrees be? Answered by Harley Weston. 





A square corner 
20100211 

From Trevor: I am building a new house and wish to set it out on site with the use of
profile boards and string. I want to be certain it is correct in terms of
squareness. I have a vague idea that the square on the hypotenuse should
be equal to the sum of the squares of the other two sides.
I get a little lost here and need some help. The building is a rectangle
measuring 40x30 feet to exterior brickwork. I guess that the length
of the hypotenuse should be exactly the square root of the combined
squares of the two sides.
Using the above measurements could you give me calculations from nuts
to soup as to the correct length of the diagonal. And what adjustments
are needed if everthing is not in accord.
Trevor. Answered by Robert Dawson. 





A dirt berm 
20100205 

From casey: My question is two fold. I want to build a dirt berm that is 95 feet long and 8 feet high which has a 45 degree angle on each side of the slope. My first question is how wide will the berm end up being? Second question is how many cubic yards of dirt will I need to get? Thanks! Answered by Harley Weston. 





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. 





The height of a roof 
20100131 

From carl: Width of my roof I am building is 5M at baseline, and the pitch is 40%.
What will the height be, and how can I work this out in the future. Answered by Penny Nom. 





Loading a headboard in a uhaul 
20100120 

From gina: I have a uhaul 9'10" long 4"9"wide 4'7"height I have a headboard 74 inches in height would it fit the box diagonally Answered by Penny Nom. 





A proof by induction 
20100112 

From Bhavya: Prove by induction that if Xi >= 0 for all i, then
(Summation Xi from 1 to n)^2 >= Summation Xi^2 from 1 to n Answered by Penny Nom. 





A magic/math trick 
20091204 

From Valentin: What is the explanation for the following math trick: you think of any four digit number add those digits take that sum and subtract it from the first number then you say three of those new numbers in any order and the other person guesses the last digit.
How does he do it? Answered by Claude Tardif. 





A truncated cone 
20091111 

From Lucian: I need to calculate the bottom inside diameter of a truncated cone.
The top insdie diameter is 1450mm.
The material is 6mm thick
The cone angle is 20 degrees
The slant length is 152mm
I would like a formula so that I can build a spread sheet Answered by Penny Nom. 





Cutting a pipe at an arbitrary angle 
20091024 

From Carol: I have read your article on cutting pipe,etc. at a 45 degree angle. I need to develop
an equation and pattern for cutting any size pipe (3" to 7") to any degree. I don't
understand how to transfer the wave pattern to graph paper.
Thanks. Answered by Harley Weston. 





What jobs use conics? 
20091022 

From denise: i have to type a paper on what jobs use conics and i can not find anything can you help
thanks
Denise Answered by Penny Nom. 





Find the intersection of y=x1 and y=sin(x) 
20091010 

From Usama: There are many modern calculators and softwares that can plot the functions.
I have two very simple equations y=x1 and y=sin(x), if i draw them manually on paper i can not get the accurate value.
But i think a computer can easily draw perfect straight and curve lines so it should be easy to find the intersection point of two lines.
Is there any way or software that can tell the exact value of intersection point of two lines? Answered by Robert Dawson and Harley Weston. 





Hexadecagon 
20090920 

From Rick: Is there an easy way to figure the even side lengths of a Hexadecagon in layman's
terms, so I know how long to cut the exterior support boards for my pool deck.
The pool is a 16' diameter Hexadecagon and my Wife wants a 4' wide splash deck
all the way around which would make the outside 24' in diameter. Answered by Chris Fisher and Harley Weston. 





Segments of a ring gasket 
20090920 

From Robert: I am in the process of making an Excel spreadsheet in which our sales
team just needs to enter the outside diameter, inside diameter, and
number of segments to price ring gaskets that are too big to fit on a
sheet of material and need to be cut into segments. With your help I
was able to create a spread sheet that can calculate the Chord lengths,
and Segment height on a single gasket segment. I am now stuck trying to
come up with a formula to figure out the height of the second segment
when it is stacked on the first segment, then use it to add more
depending on the quantity of segments needed. I have an illustration
below showing 2 segments (of a gasket that was segmented into 4 pieces)
stacked together. I need to find a formula to get the dimension from
"A" to "B". Answered by Harley Weston. 





Dart teams 
20090918 

From Sally: I have 14 dart teams. Each team has a home bar.Usually it is one week home, the next week away. I have 3 locations that have one board only, yet have 2 teams at each location. I have one location that has 2 dart boards, and 3 teams. The last location have 3 dart boards and 4 teams.Can you make me a schedule that will be home and away, and every teams plays each other twice. In case you are wondering, the bars sponsor the teams.Thank you. Sally Answered by Robert Dawson. 





Show your work 
20090902 

From Gerald: We have a 6th grade student who can solve math problem successfully without showing her work. The teacher thinks it is not fair that she doesn't show her work and the other have to and do. What sort of classroom accommodation(s) would you recommend for this type of student. It would seem to be a popular problem since there are many student who think more global than sequential. Answered by Victoria West, Penny Nom and Robert Dawson. 





How deep is the hole? 
20090825 

From Scott: If I have a hole three foot in circumference that runs at a 15degree angle from the surface and continues for a length of 100 feet, how deep would the hole be at 100 feet? Answered by Penny Nom. 





A paper towel roll 
20090819 

From Jeff: I am making a spiral tube with paper that is 2" in dia. and 102" long
I will be using paper that is slit 3" wide how many lineal feet of paper will
I need to to cover the 102"
I will be using 3 rolls of paper that will over lap the other by half to make
a hard tube (paper core) in a roll of paper towels
Thanks Jeff Answered by Penny Nom. 





Math in everyday life 
20090803 

From Naveen: Dear sir,
We are advised to do a project on "Mathematical modeling to solve various problems
of our everyday life/environmental related problems...... Can u plz help us by mailng some
ideas, suggestion,reference to make my project successful.... Thanking you......
Waiting for your favourable reply...... Answered by Penny Nom. 





The retail price for an ice cream scoop 
20090705 

From Patricia: Hi  I am trying to figure out the fairest retail price for an ice cream scoop. We have an ice cream parlor
and the cost of the ice cream we buy by the bulk container has recently been increased so now we must charge
more for our scoops. We pay a wholesale price of $25.40 for 242 ounces of ice cream. The cost per ounce is
$0.105. What is the formula for figuring out how much to charge retail per scoop? This is probably so simple
but confusing to me. Please help. Thank you! Answered by Harley Weston. 





A roll of paper 
20090705 

From mark: is there a simple way of finding out how much is left on a roll of paper. i have read similiar questions and answers on here but all seem very complicated and not being very good at maths does not help me much. some are in inches and all have different figures to mine so if i give my figures hopefully i wil understand it better. the radius of the cardboard core is 52.25mm, the radius of the paper at 2000 linear meters is 158.625mm. the thickness is 0.17mm. when nearing the end of the paper how do i work out how much is left in a simple way. thank you in advance for any help you can give me Answered by Harley Weston. 





liquid in a 3/4 inch pipe 
20090630 

From junior: We are in dilemma at my job. We need to figure out the formula for how much water can our pipe hold. It's inside diameter is 13/16" and is 50ft. long? Answered by Robert Dawson. 





The surface area of a fire pit 
20090630 

From eric: whatw is the square footage of the inside wall of a fire pit 2 feet deep and five feet in diameter? I need to estimate both the floor and wall square footage to order bricks. Answered by Robert Dawson and Harley Weston. 





Integers and decimals in day to day life 
20090629 

From mitichie: can you tell use of integers and decimals in our day to day life. Answered by Penny Nom. 





Designing a shelf 
20090628 

From Bjorn: I'm putting up a shelf and thought I'd be nice and cut the sharp and pointy
corners off. I want to the cut to be at a 45 degree angle, but I also want
the exposed edge to be the same length as from the wall to the beginning of
the cut  so the end of shelf will look like the first two sides of an octagon.
I've managed to construct the solution, but I haven't been able to calculate it...
Please help! Answered by Stephen La Rocque. 





Math jokes 
20090623 

From Emily: I am teaching a whole bunch of elementary age, kids and i need some math jokes. I need math jokes that
are about shapes, numbers anything that i can will be teaching over. this week is shapes though. Please,
and thank you,
Emily Answered by Victoria West and Harley Weston. 





An octagonal shaped gravel pit 
20090416 

From Melissa: What is the square footage of a 7'3" square ocatogon with a height of 5 inches? I need to know how much pea gravel to buy for my sons gravel pit. Answered by Stephen La Rocque. 





Winding paper after a break 
20090410 

From Olen: Question from Olen:
I work in a paper mill and have been handed the task to search for a formula to determine how much paper needs to be added to a parent roll to make up the difference at the winder. (Ex. The spool diameter at the reel is 18.25" we measure roughly 33.5" to make two 58" rolls in the winder. If the is a paper break and the roll diameter in the winder is 30" how much do I add to a single parent roll (22" roughly) to make one 58 " and the 28" needed at the winder. I would appreciate any help to complete this task. I would like to be able to build a chart that operators can refer to based on what is needed. Thank you. Answered by Harley Weston. 





An arched or round top window 
20090407 

From Dale: I need a formula to figure the lineal footage of trim require to trim an arched or round top window. The variables that I have consist of the width of the window the height of the arc and the radius. Answered by Harley Weston. 





Why learn math? 
20090401 

From Uno: I got myself in a lot of trouble today. I got into an argument in school with my math teacher because while learning geometry I said that this was useless.
I don't understand why I need to learn algebra, geometry & trigonometry.
I don't see how we use this in real life and it is almost like my teachers don't know either. They say I have to learn it because... I don't think that is a good enough answer.
The only way I don't get suspended is if I can come up with real world applications of why we learn math.
I need help... I am already in deep trouble with my parents. Any resources on how learning a proof is used in real life? Answered by Claude Tardif and Harley Weston. 





Subdividing a foursided lot 
20090327 

From kannan: i have a 1.5 acre land having four sides
AB=64.8 meters
BC=94.2 meters
CD=54.4 meters
DA=127.2 meters
angle at D is 90
the side AB (frontage)is road facing i want to split the plot in to two halves
having same almost area and almost equal frontage, kindly help me, if possible
explain with drawing.
Regards
Kannan Answered by Harley Weston. 





Octagonal panels for a horse pen 
20090325 

From Tony: I am building a pen for my horse. I am going to use 12' panels in the shape of an octagon. How many feet will he have from side to side using 12' panels.
Thanks,
Tony Answered by Robert Dawson and Penny Nom. 





The diameter of a roll of plastic 
20090324 

From truong: hi. i have trouble to calculate the diameter of the plastic roll. the sheet is 765 m long and 0.8 mm to wrap around the core 400 mm in dia. please help me with the formula to calculate the dia of plastic roll, thanks in advance Answered by Harley Weston. 





16 golfers 
20090318 

From Bill: We have 16 golfers. We golf for 5 days, in foursomes. It should work out that each player plays with each other player 1 time exactly.
I just can't figure it out.
Thank you in advance!
Bill Answered by Claude Tardif and Victoria West. 





The amount of material remaining on a reel 
20090304 

From James: Question from james:
I am after a standard calculation so that after each usage of the Reel I can get the Remaining Quantity in kilos left on the roll
below is an example of roll
THICKNESS: 30 MICRON
REEL WIDTH: 7.5 CM
REEL DIAMETER: 76 CM
REEL WEIGHT: 7.13 KILOS
The core centre has a 9cm diameter, the weight of the roll is excluding the core , and after each use the diameter of the role is measured.
I am a factory supervisor working on project and need this calculation info for template.. Thanks James Answered by Harley Weston. 





The area of a 5sided lot 
20090302 

From Linda: I have a problem I'm hoping you can provide some help with. When I check the property information for our home on our District of North Vancouver website, it shows that our property is supposed to be 1146.99 Square Metres. Yet another property which has identical measurements is listed as having 1173.7 Square Metres. I would like to figure out who is correct. Answered by Harley Weston. 





An octagonal landscaping frame 
20090301 

From Richard: Hi
I am trying to put landscape timbers down in octagon shape that measures 6
feet across and outside measures 360 degrees.. The timbers are 4 inches by 4
inches. I need to know at what angle to cut boards and at what length i need to
complete octagon.
Thanking you in advance for your kind assistance.
Richard :) Answered by Harley Weston. 





More on the gst 
20090223 

From melissa: I need to know the amount of gst that was in the amount of 630.67? How do you figure this out? I don't need the amount of gst after, but the gst included? Answered by Penny Nom. 





An octagonal poker table 
20090223 

From Corey: I'd like to build an octagonal poker table using 4'x8' sheets of plywood. I would like each side edge to be approx. 2' wide. I am sure that due to the angles I can do this with one sheet of plywood, but i don't know how to measure for this. Can you help? Answered by Robert Dawson and Harley Weston. 





A conical sleeve 
20090217 

From Jonathan: I'm having a hard time making a design pattern for a cone sleeve, the thing is the cone sleeve is 22 degrees, how can i know the angle of this when it is flat on paper, based on my calculations, it should be around 66  69, but i want it to be exact can anybody help? Answered by Penny Nom. 





The floor area in a spherical space station 
20090214 

From Ed: I am writing a science fiction novel that involves a spherical space station with a
radius of 800 meters. Inside, artificial gravity allows parallel floors set 4 meters
apart. If you count the floor that has a radius of 800 meters as Floor 0, then the
next floor up (Floor +1) would by 4 meters above the surface of Floor 0. There
would then be Floor 1 4 meters down from Floor 0. This would continue until
you reach the top or bottom floor, where there is at least 4 meters but less than
8 meters to the top or bottom of the sphere. Obviously the top and bottom
floors would have the (same) smallest area, while Floor 0 would have about 2
million square feet.
My problem is figuring out the total area of all of the floors, or for that
matter, any particular floors or the total number of floors (the total of all the
+ floors, the  floors (these numbers will be the same) plus Floor 0.
Ed Answered by Penny Nom. 





9 golfers 
20090212 

From Beth: I am organizing a golf trip for 9 women. We are playing in threesomes
and are playing four days.
I would love to mix it up so that everyone gets to play with each other
at least once. Any mathematical suggestions as to how I can make this
happen?? Answered by Robert Dawson. 





Forming an arc with 2 inch steel 
20090211 

From Craige: I need to calculate the bending radius of 2" wide steel to achieve given inside and outside arc lengths Answered by Harley Weston. 





Fertilizer in a bin 
20090203 

From Todd: Hello I am looking for a formula to figure out the fertilizer volume in a hopper bottom bin not only when it is full but part full as well. When you are filling it is heaped up in the middle to make a cone and when you are emptying the bin the cone is inverted so it would be nice to be able to quickly figure out the tonnes partly filled and when full.
Lets say the bin is 32 feet high from top of bin where you fill to the bottom where the product goes out and it is 16 feet in diameter. I know how to calculate the cylinder it is the cones on the top and bottom of the bin I have the main question on. Answered by Harley Weston. 





Calculating markup 
20090203 

From Tonya: I'm trying to figure out the formula for the following, I have a product that I want to receive a certain profit, but with this product I also have to pay a percentage of commission to someone. I need to know how to calculate my new selling price taking into account the markup percentage, but I don't want my cut to be lowered. I have calculated the markup percentage to get my new selling price with the commission, but it lowers my cut once I pay the commission and I don't want it to do that. Thanks Answered by Penny Nom. 





Ambitious 7th Grader 
20090128 

From John: I have been asked to tutor a 7th grader who is very good in math. He is taking the most advanced course that his school offers to 7th graders. This course will cover Algebra 1 over a period of two years, using McDougal Littell's Algebra, Structure and Method, Book 1, a book I like a lot.
I have been hired not to help him with his schoolwork, which is too easy for him, but to guide him through something in math beyond his schoolwork. This was his idea, an idea which surprised his parents, but one which they support.
Do you have a suggestion for me? If so, I would be very grateful to hear from you. I think this could be a lot of fun for me and my new student, if I pick the right path.
Thanks and best regards,
John
John Answered by Robert Dawson, Victoria West and Walter Whiteley. 





25,000 pounds of sheet metal 
20090127 

From JESSICA: I need to convert 25,000 lbs. of 32x48 sheet metal into total sq. feet. What would be my formula? Answered by Robert Dawson. 





An octagonal carpet 
20090124 

From Larry: I am cutting a piece of carpet that is 9 feet x 9 feet and need to cut it into an octagon. How far do I cut from the corner of the square. thank you for any help. Answered by Harley Weston. 





PST and GST 
20090120 

From janet: Hello
I need to figure what one would pay pst 8% gst 5% on a total of $1700.00
I have a small business some pay with cash I need to calculate the taxes in reverse Can you help with formula that the government might like
Thank you
Janet Answered by Harley Weston. 





Multiplying negative numbers 
20090115 

From stephanie: hi, I'm currently working in a grade 8 class where the students are
learning about integers. the students were asked to find examples of how
integers are applied in real life. they were able to find aplications for:
adding and subtracting both positive and negative integers. however,
we could not find an example of where two negative integers would be
either divided or multiplied together in real life. For example: (2)(4)= +8.
please help. Answered by Harley Weston. 





Concrete around a pipe 
20090114 

From Doug: How much concrete will i need for a hole that is 20 feet deep 20 inches in
diameter with a 8inch pipe in it. I need to know how much concrete
on the outside of the 8inch pipe. Answered by Penny Nom. 





A applied math trig problem 
20090113 

From Simon: I wish to find all the answers for the following equation over the interval (0,1):
cos^2(pi * n^x) + cos^2(pi * n^(1x))  2 = 0
where n is any integer > 0 Answered by Robert Dawson and Harley Weston. 





18 golfers and 5 rounds 
20090110 

From steve: We have 18 golfers 5 rounds .
Would like 3 foursomes and 2threesomes each day
Different groups each day. Answered by Victoria West. 





Pouring angles for a crucible 
20081220 

From Richard: I am trying to work at pouring angles and volume left in during pouring a crucible, The crucible is cylindrical and flat bottomed.
I know the diameter, radius and volume of the crucibles. and the volume of liquid going into it.
So lets say the crucible is only half full firstly I need to work out the angle just before its going to pour. ( I can work this out as long as there is a certain volume of liquid if its not enough I cant do it)
Now the problem I also need to work out how much I should tilt the crucible to allow a certain amount out and be able to do this untill the volume reaches 0 at 90' turn. This is where I am stuck.
The reason for needing to be able to work this out is so i can develop a constant flow for example 10Kg of metal per second.
Thank you very much for you time Answered by Harley Weston. 





The volume of a feed hopper 
20081218 

From John: I need to calculate the volume of a feed hopper, and I'm not sure how to break it down. The top of the hopper is 36" x 36", it is 30" deep, and ends at a 6" x 6" plate. One side of the hopper is straight top to bottom, of course tapering on two sides to meet at the plate. The other three sides angle down at about 75 degrees. I need to determine the cubic foot volume of this hopper (it is used for ground coffee) so I can configure a vibrator to knock down residual grounds. Thanks. Answered by Robert Dawson. 





Wall covering 
20081210 

From Jeanie: I need to convert 14 LY of wallcovering (54" wide) to square feet. Can you please help me? Answered by Penny Nom. 





The volume of a pipe 
20081210 

From Walter: What is the volume of a pipe 7.92 inches inside diameter and 22 km. long in cubic feet of water Answered by Robert Dawson and Harley Weston. 





Square yards of dirt cover 
20081208 

From Phillip: How many square yards will 600 cubic yards of dirt cover, at a depth of 4 inches? Answered by Harley Weston. 





Golf  24 guys 4somes 6 rounds 
20081207 

From Duane: Thank you. What about 24 guys 4somes 6 rounds everyone playing with each
other at least once.
Thanks again.
Duane Answered by Victoria West. 





What is the pre GST price? 
20081205 

From Chris: I've been looking at a few answers to the question of before and after GST price calculation.
the suggestion have been :: multiply the pre GST price by 1.10 to get the
price and reverse to get a pre GST price.
But how do you calculate the pre GST price from an existing retail price?
For example if you take an item that is $150.00 and multiply it by 0.10
you get $15.00 as the GST add on. Apparently giving you $135.00 as the
pre GST price. However if you then multiply $135.00 by 1.10 you get the
$148.50 as the total.
So the question is how does one calculate the real pre GST price from
an existing retail price?
Regards,
Chris Answered by Penny. 





Combinations of Golf Groups 
20081205 

From Duane: We have a golf outing coming up with 25 golfers playing 5 rounds in 5somes. Is there a formula to figure out where everyone can play with different people each round? Thanks, Duane Answered by Victoria West. 





6 golfers play threeball 
20081204 

From Ian: I have a group of 6 golfers wanting to play 3 rounds as 2x threeballs, but with different players each day. Is this possible? Can you provide some threeball combinations for this please? Answered by Victoria West. 





Decimals and fractions used in our daily lives 
20081204 

From josh: i have a projecct due friday and i need to know, how are decimals and
fractions used in our daily lives. i am having trouble coming up with
ideas. i need seven more that dont involve money or recipes. please
help me. Answered by Harley Weston. 





What is so important about quadratics? 
20081129 

From zoe: what is so important about quadratics? Answered by Harley Weston. 





Six golfers 
20081125 

From Joe: I have a group of 6 golfers wanting to play 3 or 4 rounds but with different players each day if possible. We know we cannot make it happen without some playing with the same person. Can you provide some pairings for this? Answered by Victoria West. 





Quadratic equations arising from practical problems 
20081124 

From Lenval: Why do quadratic equations arising from practical problems often give physically impossible solutions such as negative distances, negative times or, say, a polygon with a negative number of sides? For example: "A river in flood carries a tree tsquared  23t metres downstream in t seconds. How long does it take for the tree to be carried 50 metres downstream?" This gives t=25 and t=2. Please explain the second 'solution', which is not physically possible. Answered by Chris Fisher and Victoria West. 





Cubic yards of fill dirt 
20081122 

From Donnie: I need to know the formula to figure cubic yds of fill dirt to fill an area from 4ft. deep to 18 inches deep
this lot is on a slope and I am wanting to level 176 ft long by 4ft. deep
the sides is 115 ft. wide
the upper side is 18 inches deep. Answered by Harley Weston. 





15 cubic yards of dirt 
20081120 

From Phillip: How far, in feet, will 15 cubic yards of dirt cover, if I'm laying it 12 feet wide and 4 inches deep? Please provide formula. Answered by Penny Nom. 





An odd shaped lot 
20081113 

From Janice: Hi I am attaching a survey of an odd shaped real estate lot. I am hoping
you can help me determine the acreage.
Janice Answered by Harley Weston. 





A barrel on its side 
20081113 

From Dave: Question from Dave:
How many gallons are left in a 36x60 in. barrel (laying on its side) and has 16 in. of gasoline left. I have attached a diagram. Answered by Harley Weston. 





The cost of a steel plate 
20081105 

From Tammie: What is the formula to calculate the following:
I have a plate of steel that is 1/4" x 48" x 192" at a price of $15.23 per square foot
What is the formula to calculate the cost if I only use 1/4" x 471/4" x 681/8" of that steel plate? Answered by Penny Nom. 





The volume of a pond 
20081104 

From Malcolm: I am looking for a formula to find the volume of my pond. I know the average surface diameter and the average bottom arc length.(The arc from one bank through a point in the bottom and on to the surface on the other bank. I am not able to get a good measurement of the depth at this time. Can the volume be figured with the known measurements (the cord and the arc)? Thanks: MS Answered by Harley Weston. 





A bay window 
20081030 

From Scott: Given the length of an arc, the rise of an arc, and the number of segments
that I need to divide the arc into  how do I determine the length of each
segment? Imagine a bay window. It could have 5 side or 7 sides, just as
an example. How do I determine the width of each window given that the
unit will be mounted into a frame with a 96 inch opening. The rise of the
unit will extend out 18 inches. Lets say that the number of single windows
unit within the unit is 5. How wide should each window be? Do you
understand? Answered by Harley Weston. 





Scaling a logo 
20081020 

From Carl: Hello!
I hope that you can help me out here. I've been trying to figure this out for awhile now and can't come up with the answer logically.
I am a graphic designer by trade and need to figure out how large my client's logo should be.
The logo will need to be sized proportionally with the surface area of the page.
The logo will always be sized at 1.2938(w) x .75(h) on a letter size page (8.5 x 11).
My question is...
When you increase the size of the page (not always proportionally sized  dimensionally) how do figure out the NEW size of the logo.
I could have a page 20" x 40" or 30' x 4'... or ANY size really.
I believe I have the new surface area of the logo but can't find the new dimensions. Answered by Harley Weston. 





The area of a rug 
20081016 

From Natcha: How can I convert the Carpet Roll Size to Square Meters.
I have one Roll of carpet, (Quality is 2300 g/m2; 7 pitch/in, 9 rows/in; width: 2m) with dimension 0.5 m width and 4 m length. I needed to know that quantity of that Roll in Square Meters. Answered by Penny Nom. 





A roll of film 
20081016 

From John: I need to know how to calculate the build up on a roll of film is calculated.
Example: I start with a 6" diameter core, and I start winding .005" thick film on the core, so I am adding a total of .010" to the diameter each wrap.
If I continue to do this for a total length of film of 3000 feet, what will the roll diameter be?
So what I need is the formula to perform this type of calculation.
Can you help me? I want to be able to plug the formula in a spread sheet and to be able to input a core diameter, a film thickness and a total length and get a roll diameter. Answered by Penny Nom. 





Concrete around a pipe 
20081008 

From mick: i am trying to find the area of concrete to be placed around a concrete pipe! Dimensions can be 12m wide by 5m wide by 7m deep and pipe been 8m by 600mm radius... Answered by Stephen La Rocque. 





The dimensions of a pool 
20081008 

From Justine: This may be a really silly question but I am trying to work out what the possible dimension a pool may be if we have 20m length of wall of an above ground pool (laid out flat on ground)
We have been given a second hand above ground pool and we know it was in an oval configuration and we are just trying to get a guesstimate of the potential size it may be as the people couldn't tell us the size Answered by Penny Nom. 





An arc and an angle 
20081005 

From Cory: I have a chord length of 150'. From the left starting point, I know that
30' right of starting point is 9' in height. This would be the top of the arc.
What is the arc in degrees and can anyone display an image to help me
understand? Answered by Penny Nom. 





The area of an arched transom 
20080928 

From Ivan: What is the formula for figuring out the square footage of arched transom windows & doors? Answered by Harley Weston. 





Increase pricing by 5% 
20080928 

From Adrian: I am working to increase pricing by 5%. If the price is 100, I would typically use the formulas 100 * 1.05 = 105, which is a $5 increase. An associate suggests I divide to get the desired increase. For example, using $100 with a 5 percent increase. I would use the forumula 100/.95 = 105.26. Thas is a 5.26 increase. Can you explain this method to me an why the different increases? Which one is correct. Answered by Penny Nom. 





A three 09 tumbler lock 
20080922 

From Louis: I recently gave my daughter an old briefcase which uses a three 09 tumbler lock. She set the lock and now she can’t open one side.
Q. Is there a 3 digit combination number generator available to give me the 1000 possibilities?
Thanks,
Lou
PS In this type of lock you can repeat the same digit three times. Answered by Penny Nom. 





Cutting a pipe at an arbitrary angle 
20080920 

From John: from the original question Al asked about cutting a 200 diameter pipe in 45 degrees. can someone explain the math steps required to creating the graph. I am trying to do the same thing only using a 150 degree cut. Answered by Harley Weston. 





The weight of a concrete cylinder 
20080918 

From Curtis: I am trying to calculate the weight of a concrete cylinder. The diameter is 56" and the thickness or depth is 24". Can anyone help me? If possible I would like to see the formula as to how the answer was derived. Thank you Answered by Harley Weston. 





Art and Integers 
20080917 

From pamela: how do artists use integers? Answered by Janice Cotcher. 





Cubic yards and quarts 
20080916 

From Mary: I need 2 yards of soil, how many quarts is this? Answered by Penny Nom. 





Cutting a pipe on a 45 degree angle 
20080912 

From Bakshani: how do you a mark a pipe 5 inch diameter and cut it to form a 45 degree angel Answered by Stephen La Rocque. 





Mixing watercolour paints 
20080907 

From bob: So, I'm making a chart to help me mix watercolor paints. There are
25 different paints. Each paint will mix with another paint just 1 time.
There is no need to mix red with blue, and then blue with red. Since
the result is the same, we only need 1 combination of the 2 paints.
And there is no need to mix red with red, so we can eliminate 25
combinations of the same paint. Answered by Penny Nom. 





Mathematical induction 
20080905 

From James: I need to prove a problem by induction regarding the Triangle Inequality. The problem is
abs(a1 + a2 +...+an) <= abs(a1) + abs(a2) +...+ abs(an). Answered by Victoria West. 





20 golfers playing 5 rounds in 4somes 
20080903 

From joe: 20 golfers playing 5 rounds in 4somes. 5 players in group A play with all 15 golfers in groups B,C,D but not with any in their own group (A).
5 players in group B play with all 15 players in groups A,C,D but not with any in their own group (B) and so on. So each 4some has an A,B,C,&D player each of the 5 rounds. Answered by Chris Fisher. 





GST and PST 
20080825 

From Monique: okay i live in ontario and i want to find out what my grand total will be so
i know how much i will have to pay...
so if i have a before tax total of $48.40... what will my grand total be? with
GST and PST i know that GST=5% and PST=8% Answered by Penny Nom. 





The volume of a ditch 
20080812 

From John: Question from John:
I am trying to figure out how much flowfill I will need for a ditch that we are digging out. The ditch is 300' long and is 4' deep on one end and 2' deep on the other end. We are going to dig this ditch out and replace it with a flowfill concrete material. How much flowfill material will we need or what is going to be the volume of this ditch? Answered by Penny Nom. 





Square miles 
20080806 

From Koni: I'm trying to figure out the distance our buses travel throughout our district to pick up students for school. How do you figure square miles?
If our district measures 6 1/2 miles wide and 2 3/4 miles deep, what is our total square miles? Answered by Penny Nom. 





The best time to teach math 
20080803 

From Kelli: Is there a best time to teach math in the elementary classroom? Has anyone done any research about this? Answered by Stephen La Rocque. 





The volume of a fuel tank 
20080801 

From G.: I have a fuel tank that is 70 inches by 48 inches and 24 inches deep, how many imperial gallons does it hold? Answered by Victoria West. 





Lot size of a four sided lot 
20080730 

From JAMES: I'm trying to find out this lot
size in acres.
I looked at a bunch of your suggestions, but I guess
I'm not smart enough
to figure it out.. I have attached an image of the
lot, hopefully with
enough info. for you..
Thanks,
Jim Answered by Penny Nom. 





Problems understanding math 
20080727 

From Cindy: why do so many people have problems understanding math.
is it because at some point along the way they didn't fully understand
a concept and they then lose confidence. Learning math is cummulative so what you
don't learn at one point just gets more confusing as you move along. how do
we correct this? how can i help students in junior and senior high who do poorly in math. Answered by Stephen La Rocque and Victoria West. 





Volume of a Shed 
20080724 

From lou: I need to know the interior volume in cubic feet of a shed with the dimensions 8' x 10' x 7' with a roof peak of 9'. Thanks Answered by Janice Cotcher. 





How many gallons of fuel still in the barrel? 
20080722 

From Charles: I have barrel 6 feet long and 3 feet diameter that is laying on it's side with 5 inches of fuel, how many gallons of fuel still in barrel Answered by Penny Nom. 





Taking two math classes 
20080721 

From Bailey: i am going into the 7th grade, but i am going to be taking 9 th grade math.
i was wondering if anyone could help survive doing two different math classes at the same time. Answered by Harley Weston. 





How much sand do I order? 
20080715 

From jackson: We would like to put 2 inches of sand down. The pool is 24 feet.
How much sand will we need?
The person we spoke to yesterday was talking in tons, but on these sites it is
talking cubic yards or feet.
Please help. We would like to get the sand ordered so we can get the pool up! Answered by Harley Weston. 





Chords and arcs 
20080711 

From Ronnie: We are trying to build a semi life size ark decoration , and we are trying to cut the sides out . The curved sides and we can't figure our radius , all we know is that our chord length is 24ft. any suggestions on how to find the radius or maybe even the arc length or circumference or diameter? Answered by Harley Weston. 





Mathematical induction 
20080711 

From lyn: can you give me a basic example of a mathematical induction Answered by Harley Weston. 





A four sided lot 
20080709 

From michelle: the front is 65.29
left side 162.26
the back 155.00
right side 101.01
right angle=50.00
left angle= 153.30 Answered by Harley Weston. 





GST and PST 
20080702 

From Sharon: The question was asked before but it was based on a G.S.T of 7% and I am now interested in the answer for 5% G.S.T.
It usually comes up when I husband bring homes a gas bill that doesn't break down the gst and pst, but rather just gives him the total cost I have to know how much GST he paid. If it is Diesel the PST isn't included but if it is regular gas he pays both. PST is 7%. Answered by Penny Nom. 





A six sided lot 
20080625 

From Zack: Please help me find the area of my lot. I am sending a fax of the drawing and dimensions.
Zack Answered by Harley Weston. 





A golf tournament 
20080624 

From Roland: We have a golf tournament, 12 players, three rounds. We want to pair so that we have pairings with as few duplications as possible. Answered by Janice Cotcher. 





The sum of the digits of a number 
20080623 

From Ben: Question: Using mathematical induction, prove that if the sum of the digits of a number is divisible by three, then the number itself is also divisible by 3. Answered by Penny Nom. 





Concrete blocks 
20080618 

From marvin: How many cement blocks do i need to build a 8 ft. tall wall x 1,300 ft. long? Answered by Harley Weston. 





Percent difference? 
20080614 

From Cathy: I am trying to verify a "percent of difference" as stated on a tax form. I cannot seem to come up with the equation to do so.
Here are a few examples on the form:
Last year $62.91 this year $66.05 tax difference $3.14 percent difference 5.64%
Last year $ 2014.97 this year $1982.93 tax difference $32.04 percent difference 57.56%
Last year $97.66 this year $79.58 tax difference $18.08 percent difference 32.48%
I have tried several different ways and per some of Q&A's already on your site I still have a problem and would appreciate some assistance.
ThanksCathy Answered by Penny Nom. 





Escort cards on a rectangular table 
20080613 

From Susan: What size rectangular table will we need to put 230 2" X 3.5" escort cards on for my daughter's wedding reception with a spacing of .5 inch between them on all sides? Thanks so much for your help Answered by Penny Nom. 





Rectangular cards on a round table 
20080611 

From Susan: How many 4" X 3.5" wide escort cards will fit on a 48" diameter table. These are for my daughters wedding. I have already added the extra spacing between the cards into the size of the cards.Thanks for your help Answered by Janice Cotcher and Harley Weston. 





What is the GST component? 
20080611 

From Jilly: I need to find a quick and easy formula for finding the gst (10%) of the total amount in $ terms, eg: the total is $500 what is the gst component? Answered by Penny Nom. 





Packing a truck 
20080610 

From Ann: I am renting a 24ft box truck and have been told it is 1401 cubic feet. I want to know if I have 23 display cases to move and each is 6ft X 2ft X 3ft will the all fit? Or do I need additional info in order to figure this out? Answered by Penny Nom. 





Filling a hole with sand 
20080605 

From greg: I have a 18 ft. diameter circle and need to put 2 in. of sand in it i need to know how much sand in cubic yards and tons Answered by Harley Weston. 





I want to fill my backyard slope with fill dirt. 
20080525 

From Piero: I want to fill my backyard slope with fill dirt. The slope is 50 feet wide and the distance from the top of the top of the slope to the bottom is about 15 feet deep and the slope angle is at a 45. I want to know how many yards of dirt do I need to fill a space that is 20 feet out, 15 feet deep at a 45 degree angle. Answered by Stephen La Rocque. 





Ten acres 
20080525 

From RICHARD: hi, i am getting 10 acres of ground from a aunt which is going to be taken out of a 50 acre tract.both the north and south lines are 1320 feet long.i need to know how long the east and west lines will be to make the 10 acres and what the square footage will be for the 10 acres Answered by Harley Weston. 





Applications of trigonometry 
20080524 

From Mohita: I have got a project in the school and i am not getting anything about the topic. The topic is that we need to find the application of trigonometry on any one of the real life situations using 3dimensional figures. I mean how can trigonometry can be used in real life situations like navigation, architecture, survey, astronomy etc. Answered by Penny Nom. 





A 9 team flag football tournament 
20080522 

From James: I like to run a 9 team flag football tournament where each team is guaranteed 3 games prior to playoffs. All games must have playoff implications and must not be a consolation game. Answered by Victoria West. 





A season schedule for 9 teams 
20080522 

From James: would like to put together a season schedule for 9 teams with each team playing three or 4 games leading to a 1 to 9 ranking. Answered by Victoria West. 





Volume/weight of a salt shedweight 
20080521 

From James: How do I find the volume/weight of a salt shed. I have a 3000 ton barn, I need a better way of finding how much salt to order as it gets used. I know how to calculate volume, how do i get tonnage from there?? Answered by Harley Weston. 





Covering the bottom of a pool 
20080521 

From Chris: I need to know how many sheets of 4 foot by 8 foot by 1 inch foam
I will need to cover the bottom of a 27 foot diameter pool? Thanks! Answered by JaniceCotcher. 





A weird shaped lot 
20080521 

From James: Need to find square foot of a residential lot on a culdesac. Weird triangular shape. Measurements : 126.18 170.08 138.2 48.4 Answered by Harley Weston. 





The length of an arc 
20080516 

From Don: I am trying to determine the length of an arch with a two foot backset from 32 foot frontage. Answered by Harley Weston. 





Tyres in a shipping container 
20080514 

From Carlene: I need to work out how many tyres will go in a shipping container.
The shipping container is 10 foot long, 8 foot wide and 8.6 foot high.
The tyre is 175 millimeters across and it is 14 inches in tyre thickness.
How many tyres will fit in my container? Answered by Stephen La Rocque. 





Searching for an adult math anxiety course 
20080513 

From Helen: Hello
I am a professional female in my 30's with an continued fear of maths, particularly mental arithmetic. I've been able to keep my 'secret' hidden until now but I dread that one day I'll be found out.
More importantly, it is preventing me for applying for promotion where I know maths will be required. I've tried many times on my own to overcome this but soon get frustrated.
Therefore, I've been searching the internet to find short (up to one month) courses specifically adressed to alleviating my fears and hopefully teach me maths again in a way that I can remember and not get flustered.
Unfortunately, I have not been able to find anything at least not for adults.
I would be wiling to take a long vacation to attend this type of course, or tutoring, in any country.
I'd much appreciate any pointers.
Helen Answered by Walter Whiteley. 





The volume of a ditch 
20080509 

From Dixie: I need to find the cubic feet of a ditch 36 inches wide by 28 inches high, by 1561 feet long.
then I need to convert it to cubic yards then to tons. of rock Answered by Penny Nom. 





An octagonal prism 
20080427 

From Melanie: My son is identifying geometric shapes in the real world? We are stuck on octagonal prism, rectangular prism and square prism. Can you help me out with some examples. Thanks Answered by Penny Nom. 





The volume of a triangular shaped pond 
20080410 

From Bret: we have a pond that is triangular shape : 130ftx130ftx150ft and is 4ft deep. How can I figure out as to how many gallons of water it will take to fill it up? Thanks for your help :) Answered by Penny Nom. 





Cutting a 200 diameter pipe at 45 degree angle 
20080410 

From Al: i want to cut a 200 diameter pipe in 45degrees. Can you demonstrate how to develop a flat rap around please Answered by Harley Weston. 





How many bags of mulch? 
20080407 

From MJ: I have an area that is 35' X 50' and I want to cover it with 2" of mulch.
Do I take length X Width X depth? Bags of mulch are sold in 2 or 3 cubic feet per bag.....I just want to know how
to do the math. can you please send me the equation? Answered by Penny Nom. 





A 100 acre square pasture 
20080403 

From Richard: I need to know how many lineal feet there is around a 100 acre pasture that is square in shape. I am no longer able to get out and measure it myself, and cannot remember the math to compute it. Answered by Penny Nom. 





How long will it take to pump the water out of the basement? 
20080401 

From Shiva: I need to pump water out of a flooded basement, using two 50 (gpm) pumps. The basement has the dimensions shown and is flooded to a depth of 16 inches. How long will it take to pump the water out of the basement? Answered by Harley Weston. 





Packing a trailer 
20080401 

From Shellie: I have a trailer that is 8 ft x 5 ft. I have a hutch base that is 32 in
x 52 in,
hutch top is 47 in x 52 in, table 56 in x 44 in, 6 chairs that are 48 in
x 20 in.
I know that the cubic feet of the trailer is l x w x h=3D 5 x 8 x 5=3D 200
cubic feet
I know that the area of the items are approximately 1026 feet.
How do I
know
if these things will fit? I would like to know the math behind it? Answered by Penny Nom. 





I have to fill a hole with clay 
20080331 

From Tim: Dear Sirs I have to fill a hole with clay and then 8 inches of top soil. The area is a 24 foot circular hole left by a now removed swimming pool. The area in question pithces from the house from 48" to ground level within that 24 feet. I was wondering how many yards o the top soil has to be 58 inches deep thank you f fill(clay) I would need and how many Yards of top soil to cover that hole Answered by Harley Weston. 





How many bags of cement do I need 
20080330 

From Joe: How many bags of cement do I need if I want to extend my carport 6 inches all around?
The carport is 15ft. x 15ft. and the existing slab is 4 inches thick. Answered by Harley Weston. 





A fish tank in the shape of an irregular pentagon 
20080329 

From richie: i am building a fish tank. it is going to be an irregular pentagon. the sides are going to be
24"
24"
8"
8"
32"(approximately)
there will 3 right angles A, B, E
my question is how to figure out the degree of the angles that are not right angles (C,D)? Answered by Chris Fisher. 





A car tire full of concrete 
20080327 

From robert: I want to build a volleyball net support. I am using a car tire 24"odx16"id filled with concrete. how much will this weigh? thanks Answered by Penny Nom. 





The length of the ramp on a motorcycle trailer 
20080325 

From Joshua: I am currently building a motorcycle trailer. I am trying to figure out the length of the ramp so that the bikes don't scrap the trailer/ramp as they are loaded. This is the info I have: the motorcycle is 6" off the ground in the center, the point where the tires touch the ground are 80" apart, the trailer deck is 20" high. How do I figure the length of the ramp? Please show equation so I have for future reference with different measurements. Answered by Stephen La Rocque and Harley Weston. 





A hydraulic cylinder 
20080324 

From james: I am trying to adjust the placement of a hydraulic cylinder that raises a dump bed up from the frame of a truck.
How long would the cylinder (height of a triangle) have to be to raise the bed to a 70 degree angle?
The base from pivot to cylinder is 132.5 inches. Answered by Stephen La Rocque. 





Twenty golfers 
20080316 

From john: I have a group of 20 golfers. We plan on playing 6 rounds of golf in 4 days. I would like to have the most possible combinations of players without each player playing with anyone if possible, in the 4 days of golf Answered by Victoria West. 





Mathematics in cooking 
20080315 

From Emily: What forms of Mathematics are used in Cooking? Answered by Harley Weston. 





I need to level a 18ft x 21ft area that is very uneven. 
20080304 

From Shelia: I need to level a 18ft x 21ft area that is very uneven. I have used a line level to determine the number of inches at various places in the area. This varies from 1 inch to 15 inches in order to bring the garden area up level. How do I calculate cubic yards so I can order topsoil for the area. If needed, I have the number of inches needed for each square yard area. Answered by Penny Nom. 





Pea gravel 
20080224 

From Linda: I have a space of 16 feet by 8 feet. I want to fill it with pea gravel 6 inches deep. If the bags of pea gravel are
.53 cubic foot. How many bags would I need. Thanks so much. Answered by Stephen La Rocque. 





1/(1x2)+1/(2x3)+1/(3x4)...+1/(n(n+1)) 
20080220 

From hossun: Find a formula for 1/(1x2)+1/(2x3)+1/(3x4)...+1/(n(n+1))
by examining the values of this expression for small values of n.
Use mathematical induction to prove your result. Answered by Stephen La Rocque. 





A real life example of a decagon 
20080212 

From Htet: I have a math dictionary to complete by February 13, 2008, Wednesday, and I need to know what a real life example of a decagon can be. I need help on this! Answered by Penny Nom. 





Total profit 
20080203 

From Rhonda: I help to manage a concession stand. We sell a variety of items. Some have a profit of 60%, some 80%, etc. We have done nothing scientific to choose our prices. We just try to stay in the ballpark of schools around us. Our administrator wants to pay those that run the concession stand a percent of what is in the cash box after startup money is taken out. We have some gathered some data (not much) on how many of each item we sell and can certainly calculate percent profit. Is the profit for the entire concession stand a weighed average? I'm thinking (% profit on candy)(number candy sold) + (percent profit nachos)(number nachos sold) + (percent profit pop)(number pop sold), etc. Will this work? Does the AMOUNT of profit for these different items need to be figuredin? Hmmm. . . Answered by Victoria West and Harley Weston. 





The size of a lot 
20080202 

From linda: Hi, could you please tell me how close to an acre of land my lot is. The lot size is 140 ft by 200ft. I am trying to see how close to an acre it is. Answered by Penny Nom. 





Tiles on a basement floor 
20080131 

From ORIETTA: I have a basement 1000 sq ft I want to purchase tile that are 18x18inches
and they are charging 4.15 sq ft how much would it cost since I will need
less tiles to cover the area since it's not 12X12 Answered by Penny Nom. 





The acre measurement of a property 
20080130 

From Kim: I would like to know the acre measurement of a property that is 673.68 feet by 820.76 feet. Answered by Penny Nom. 





Belledout pier 
20080128 

From Gina: I need to know how to find the total yards needed to fill a concrete pier that is 54"/ 108" and 26' deep.
That is...54" @ the top of the pier belled to 108" @ the bottom...26' deep. Answered by Stephen La Rocque. 





Out of school applications of Pythagoras Theorem 
20080123 

From Laura: Hi,
I am currently working on a math summative in which I have to choose a real life subject and relate it back to the material in my grade 12 math class. I find the history and discovery behind the Pythagorean Theorem and Identity very interesting, but I have yet to find a reallife application of the equations. Yes, I know they are used for finding distances, heights etc., but realistically, how many people actually use it in those situations? Very few. I was hoping for a new application. Is the pythagorean theorem (sin^2x + cos^2x = 1) even applicable? Thank you,
Laura Answered by Harley Weston. 





A 16 sided lot 
20080116 

From R: I am having a land of 16 irregular sides i know all the length of the sides how to calculate the
area of the land Answered by Harley Weston. 





How many rolls of stock do I need to buy? 
20080116 

From Dan: How many rolls of stock do I need to buy?
Given:
The rolls are 40" wide, 20" roll o.d., 4" core o.d., gauge is 0.008"
I need to cut these master rolls in 6" strips (4" of waste per master roll)
and I need 1,270,500 linear feet of this strip. Answered by Stephen La Rocque. 





How many bags of cement will I need? 
20080115 

From James: I want to extend my front porshe more to the left atleast 14' 1" length wise and 5' 1" width wise with 4" thickness. Now i already decimalized in feet those inches, resulting with 14.08 length and 5.08width and 0.33 of thickness. I then Get my square feet of 71.53. And go on to cubic feet getting a 23.60 in cubic feet. Now i want to convert to cubic yards so i then divide 23.60 into 27 and get 0.87. Now my question is how would i use this to go and buy the necessary bags of cement knowing that a 94 lb. bag of cement is 1 cubic foot of bulk material. To fill 4 inch of thickness and 14' of length and 5 of width? Answered by Stephen La Rocque. 





Practical applications of sequences 
20080101 

From carl: can you give me examples of different kinds of practical applications of sequences? Answered by Penny Nom. 





An irregular octagon 
20071223 

From Sheldon: I am attempting to construct an irregular octagon picture frame out of bamboo. The bamboo is 1" in diameter and the opening should be 20" H X 16"W.
What measurements should be used? Answered by Penny Nom. 





The Principle of Mathematical Induction 
20071215 

From iris: we have some confusion in our problem. Please help us.
We would like to know "the principle of mathematical induction"
(i) for n=1, p(1) is true.
(ii) assume that for n=k>=1, p(k) is true we have to prove p(k+1) is true. Here (Is n=k>=1 true? or Is n=k.1 true?)
Thanks. Answered by Penny Nom and Victoria West. 





Negative numbers 
20071214 

From mannal: what negative integers do we use in the real world? like 30 temperature? Answered by Penny Nom. 





Is math anxiety a learning disability? 
20071213 

From Steven: Is math anxiety a learning disability? Answered by Victoria West. 





Bags of concrete 
20071206 

From Chris: I need 1 and one half yards of concrete for a project. If one bag is equal
to 0.38 cubic feet, how many bags will I need? Answered by Penny Nom. 





The diameter of a gasket 
20071201 

From Jorge: I have an application where I am using a circular silicone gasket. I have the total length but would like to calculate the diameter with the given length. What formula should be used? We receive these gaskets in a roll and cut them about 21 inches and glue the ends together to make it one piece. I would prefer to purchase these already cut and glued but require a diameter. If I had the overall diameter from a 21 inch length gasket, I can look online for a part that comes close to the diameter.
Jorge Answered by Harley Weston. 





The square footage of a property 
20071130 

From Warren: The west property line is 240' long with a 90degree angle to the south property line.
The south property line is 493' long with a 90degree angle to the east property line.
The east boundary is 165' long.
The length of the north property line is not known but it is a straight line from the north end of the east property line to the north end of the west property line.
Could you please tell me the total square feet and how many acres?
And how you calculated the answer Answered by Penny Nom. 





An arched entry 
20071128 

From amber: i am working with an arched entry. i know that the radius is 25' and the height is 20'11". i need to know the length of the arch and degree of bend of the arch. how do i find these? Answered by Stephen La Rocque. 





Straight lines 
20071126 

From Divyansh: hello
i am in eleventh class and am, preparing a project on straight lines
i cant really find uses of straight lines and its equations in daily life
i am also thankful to you in advance and am waiting for your answer eagerly because i need to submit my project only this week
thanking you Answered by Penny Nom. 





Area of a 17sided lot 
20071121 

From Lynda: My uncle is wanting to buy this piece of land [a 17sided polygon] but we are questioning the acerage total. the measurements are [on the attached diagram]. Answered by Stephen La Rocque. 





How many yards of fencing do I need? 
20071116 

From Terrie: I have to order fencing for a 25acre, rectangular field.One side of the field is 1/4 mile. How many yards of fencing do I need to enclose the field? Answered by Stephen La Rocque. 





A cylindrical tank 
20071116 

From Mario: I want to determine how many gallons i have inside a cylinder (tank) that is resting on its side (the Height), NOT standing up.
I know V=pi x r2 x H. And 1 cubic foot = 7.48 gallons. Here are the dimensions r=2' H=20'. Now my question is how do I determine how much
liquid i have inside, if the level of the liquid is about 1/2 of the way of its Diameter (in other words 2'). Remember this cylinder is lying
on its side. Answered by Penny Nom. 





How many yards of dirt? 
20071116 

From wade: i own 4acres of land and would like to fill it with 10inches of dirt can you tell me how many yard of dirt it will take to do so Answered by Penny Nom. 





Our company charges a 4% margin 
20071113 

From Nadja: Our company charges a 4% margin on top of a pay rate to obtain the total charge rate. A
client is denying that the total charge rate is calculated in the following
way:
Pay rate/0.96 = Charge rate
Please could you provide me with an explanation which I can pass on as
to why it is calculated in this way? Answered by Penny Nom. 





Is there a practical use for radian measure? 
20071026 

From Paula: Is there a practical use for radian measure in any profession? Which professions might us radian as opposed to degree measure? Answered by Harley Weston. 





I need to rebuild a wagon wheel 
20071026 

From Pat: I need to rebuild a wagon wheel, the metal wheel rim is 41" diameter, inside the rim is a one and a half inch by one and a half inch wood wheel.
I thought I would glue up a hexagon from a 2x6 or 2x8 piece of wood and then draw and cut out the 41" diameter wood circle.
? what would work better the 2x6 or the 2x8 and what is the lenghth of the cuts needed in order to give me the 41' diameter I need. Answered by Harley Weston. 





Stanley Cup costume (truncated cone pattern) 
20071019 

From Janet: You hockey fans will love this question. I am making a Stanley Cup halloween costume and need a flat pattern for the bowl portion. I believe a truncated cone will work nicely. Base circumference needs to be 32" (10.19 diameter). Top circumference needs to be 44" (14 diameter). It needs to be 8" high. Thanks for your help. Answered by Stephen La Rocque. 





An octagonal table 
20071018 

From Lorne: I am 77 years old and want to build a table top with each side measuring 23 inches.
I believe the diameter would be 55.5 inches. Is this correct and what is the angle of the cuts I have to make? Thank you for your patience. Answered by Penny Nom. 





How many cubic yards of dirt do I need? 
20071016 

From BELINDA: I need to fill an area of 30,000 square feet with dirt that is 18" in height. How many cubic yards of dirt do I need to do this? Answered by Penny Nom. 





A 9 team league 
20071011 

From Dary: I have a 9 team pool league. Each team must play each other once only. But 2 teams cannot play at the same place location each week. I can't seem to match this up and I get stuck. Answered by Victoria West. 





Mixing cement 
20071009 

From Sandra: How many bags of cement do I need for a floor for a house that is 8meters long, 8meters wide and 50cm deep. Answered by Stephen La Rocque. 





calculating percentages for my class 
20071009 

From Cori: I teach a class in which there are seven projects/quizzes worth 10% each,
and the midterm and the final are each worth 15%. No problem figuring out
their final grade, but I have to give a midterm average, having only FOUR
of the seven 10% things, and the midterm test. The closest I've come to
an accurate "average" is to just add them together (as equals) and average them. Answered by Victoria West & Harley Weston. 





Golf pairings 
20071002 

From Mike: Regarding arranging golf players so no person plays with anyone more than once.
You have given examples for 16 and 24 players. If it can be done, i need a
solution for 20 players, 4 players per team one round per day for 5 days Answered by Victoria West. 





The amount of dirt 5 feet deep over a 50 acres 
20071002 

From Debbie: Please tell me how to calculate the amount of dirt stripped 5 feet
deep over a 50 acre site. How do you calculate the amount of dirt in an acre
and then excavating it a certain depth. How does one calculate the amount of
dirt excavated and moved and how to price to charge for the service? Answered by Stephen La Rocque and Victoria West. 





Irrational functions 
20071001 

From alicia: i have a question about irrationals functions.
i have been using them quite some time now, but i wonder where they can be found in daily life?
i hope you can help me, Answered by Harley Weston. 





400 square yards of sidewalk 
20070927 

From Vanessa: I am having a small problem being a subcontractor
I'll having trouble calculating how much concrete it will take to pour a 400 square yard sidewalk 5' wide 4" depth can you show me the equation to figure out how many yards of concrete i will need. Can you help me please?
Thank you very much and have a wonderful day. Answered by Penny Nom. 





The incline of my yard as it slopes away from my house 
20070922 

From Janet: I need to calculate the degree (or is it percent?) of incline of my yard as it
slopes away from my house. Do I visualize a right angle formed by a
level line from the bottom of the slope to the side of the house, and then
compare the line of the slope against the right angle to get the degree?
Or is an incline calculated by the measurement of the rise in 100 feet? For
instance, if the ground rises 3 feel in a distance of 100 feet, is that a 3%
incline? And if it rises 4 feet in a distance of 25 feet, is that a 16% incline?
Thanks so much. Answered by Stephen La Rocque. 





How students learn math in other countries 
20070920 

From Patricia: I'm desperately searching the web for information on how students learn math in other countries. Years ago I had some worksheets that explained the addition algorithm as it was taught in other countries. That is the sort of thing I need. I teach 6th grade math in an urban school and have many students from other countries (Mongolia, Somalia, Ivory Coast, Honduras, Serbia) I want to celebrate their heritage while helping them learn the basics of 6th grade math. Answered by Diane Hanson. 





Area of an irregular lot 
20070920 

From Joanne: I found your web site through ask.com & it's great. Really hoping you can help me. We are looking at purchasing an existing home with a lot size that is advertised at 2.04 acres, however, even with my limited math skills I know this is not correct.
Their calculation takes the deepest part of the lost (179 feet) multiplied by the widest part of the lost (497.26 feet) as if it was a perfect rectangle. As you can see from the faxed diagram it is far from rectangular in shape.
Can you advise as to the true lot size? As I mentioned we are looking at this property as a purchase so time is of the essence.
I have also faxed this information (with the diagram) to the number listed on your web site. Thank you so much for your help. Answered by Harley Weston. 





Filling a planting bed 
20070918 

From Luke: How many 40lbs bags will it take to fill area 21feet long 45inchs wide 9 inch deep? Answered by Penny Nom. 





How do I determine how many tons, 15 yards of top soil is? 
20070918 

From Terry: One company is selling topsoil by the yard and another by the ton,
how do I determine how many tons, 15 yards of top soil is? Answered by Penny Nom. 





How much stone will be needed to fill the trench? 
20070914 

From Debbie: A trench 100metres long 1ft wide*18inches deep with a 4inch pipe laid. How much stone will be needed to fill the trench.
How much weight in stone would I need to fill it? Answered by Penny Nom and Victoria West. 





Two inches of topsoil 
20070910 

From Nick: I have to cover a 5,300 square feet area with topsoil 2" deep. How many yards would I need? Answered by Harley Weston. 





How many cubic yards of concrete? 
20070831 

From Teresa: How many cubic yards of concrete are required for the structure with a bottom piece that is 8" high by 72" by 72", a side that is 8" by 72" by 60", another side that is 8" by 72" by 60 ", a side that is 8" by 72" by 60" with a circle cut out that has a radius of 18", and finally another side that is 8" by 72" by 60" that has a circle cut out that has a radius of 12". Answered by Stephen La Rocque. 





Is there a way I can calculate correct square footage for odd shapes? 
20070831 

From Tom: I manage a golf course, and we are about to over seed the course for the upcoming winter months. We will be over seeding all greens, fairways, and tee boxes. Noone of the area that we will be placing seed on is a regular shape. The closest shapes they would be is a circle, rectangle or square, but most of them are all odd CURVED shapes. I know what the equation is for Square ft., and I know how many Square ft. are in an acre, but I need to be precise with the amount of seed I order. Is there a way I can calculate correct square footage for odd shapes. Answered by Harley Weston. 





Applications of sequences and series 
20070827 

From Trish: I'm a grade 12 learner working on a math project based on sequences and series. I'd like to know the different types of sequences and series such as fibonacci, fourier, farey, etc.
I've already used the Fibonacci Sequence and Harmonic Series
and need two more.
The simpler the sequence or series type the better.
I'd also like to know in which nonmathematical areas use sequences and series
and how.
Areas such as engineering or science. Answered by Penny Nom. 





Filling an old swimming pool 
20070827 

From Russ: I would like to know how much fill material I would need to fill an old swimming pool. The pool is 18' wide x 36' long and is 4' to 10' deep. Answered by Penny Nom. 





Where do you use trigonometry? 
20070821 

From jenny: where do you use trigonometry besides architecture and engineering? Answered by Stephen La Rocque. 





Markup 
20070820 

From Drew: I own a manufacturing business and I need to figure out the best way to mark up our products so that we can make a profit for this year. Say for instance we have a plow that we can make for $938.00. We need to mark it up 20% so that we have some income. Do we take the $938 x 20% = $1125.60 or $938 / 80% = $1172.50? Answered by Stephen la rocque and Harley Weston. 





I want to fill the hole up with dirt 
20070819 

From Roger: I have an 18 foot round hole which is 16 inches deep. I want to fill the hole up with dirt. How much dirt do I need to fill the hole?? Answered by Penny Nom. 





The area of a five sided lot 
20070819 

From Karyn: I have been looking at your site, but I am still confused as to how to
figure out the exact square footage of my irregular lot (since it is a gradual fan
lot from the front, and triangles out in the back). Answered by Harley Weston. 





When is the best time in the day to teach math? 
20070813 

From Sarah: Do most teachers teach math in the morning or the afternoon? Is it true that kids learn and absorb more information in the morning? When is the best time in the day to teach math? Has there been any research on this? thank you! Answered by Stephen La Rocque. 





Water bill woes 
20070812 

From Terry: I know that a cubic foot of water=7.48051945 gals., but I keep getting my water bill and they go by thousands of a gal. per cubic foot. Is there a conversion that says that shows this? Water department=.763 x cubic foot used=thousands of gallons water used that month. Exampel: 72cu. ft meter reading x .763+ 58. galons of water I use in a month. Total 58=thousand = +gallons. This is wrong. There are only two people in the house. Answered by Stephen La Rocque. 





GST and PST 
20070811 

From Cynthia: I paid $15.98 for an item. Both GST (.96) & PST ($1.12) were added for a total of $18.06. I know that .96 is GST (6%) and $1.12 is PST (7%).
Other than looking at the receipt, if all I have is the total amount paid, how do I calculate how much of the total are taxes? Answered by Penny Nom. 





An old bike lock 
20070808 

From Jeremy: I have an old bike lock i found in the garage of the house i just moved in to. It has four columns and the nubers are 1 through 6. I understand that there are 1236 (6x6x6x6) possibilities. Is there a graph of all the possible combinations cuz i looked all over the web and couldn't find one. Answered by Penny Nom. 





I want to learn math 
20070807 

From Maria: Hello. I am 16yearsold, and I would like to learn as much mathematics as I can
and to really understand it. I would like to know what people mean when they
say things like "thinking mathematically" or "math is equally beautiful and true".
However, I'm not sure where to start. :) What do you think of going back to the
beginning and working my way through Euclid?
Your help would be very much appreciated. Thank you. Answered by Harley Weston. 





Dirt in a sloped round hole 
20070803 

From Ken: How much dirt do I need to fill a ground hole 20 ft in dia. with a sloping floor that has a ht. of 5" on one side and 12" on the other side? Answered by Stephen La Rocque. 





A gas tank 
20070801 

From Randy: I am trying to determine the size of the gas tank on a used truck I just purchased. There is no tag on it showing the size. It measures 50" wide by 12" high by 18" deep. How many gallons of gas does it hold? Answered by Penny Nom. 





An irrigation ditch 
20070731 

From Kevin: I would like to know how many cubic yards of concrete I would need to fill a section of irrigation ditch that measures 12 inches on the bottom, 40 inches on top, 16 inches high and 20 feet long with a 18 inch diameter, 20 foot long culvert sitting in the ditch (to remain open). I am trying to build a roadway across the irrigation ditch. Thanks very much. Answered by Penny Nom. 





Building a garage 
20070729 

From charles: I want to build a garage that is 24 feet 4 inches wide by 50 feet long.
can you please tell me what the length of one corner is to the other? Answered by Penny Nom. 





320 acre lots 
20070729 

From melisa: we are splitting a 320 acre parcel into five 35 acre lots with one 145 ace lot. I have the footage of each side there are eight:
5280 x 2640x2640then out1320x1320up x2640back inx1320upx1320this now would meet back to the 5280foot side i know there is a half of a square mile and 320 acres.what would the measurements be in feet for length to make a square or a rectangle to make a 35 acre lot? Answered by Harley Weston. 





A pile of soil that is 284' around and 12' high 
20070726 

From bev: I have a pile of soil that is 284' around and 12' high. I need to know how many yards are in that pile. And then how do I convert that to cubic yards Answered by Penny Nom. 





The volume of a cistern 
20070719 

From sharon: We have a cistern to hold spring water that measures 12 feet in depth by 5 feet in diameter. How much in liquid gallons will it hold? Answered by Penny Nom. 





Pythagoras theorem in daily life 
20070717 

From sana: i would like to what are the 5 practical uses of the Pythagoras theorem in
daily life??? its for a math project
thanx a lot
sana Answered by Penny Nom. 





Five button push lock 
20070706 

From Jeffrey: We have a 5 button push lock and we were wondering how many different codes were possible in this situation. In this lock each button can only be pressed once (ie it's not a numbered key pad) and order matters. How would we find out the # of possible codes? Answered by Stephen La Rocque. 





Tons of concrete 
20070703 

From Trey: I have 300,000 square feet of concrete and want to know how to convert this to tons? Answered by Harley Weston. 





The volume of a pool 
20070703 

From maria: we have a pool that is 2 feet by 5 feet by 3 1/2 feet  how many gallons of water does it hold Answered by Stephen La Rocque. 





I need to provide 712 cubic feet to water storage capacity 
20070703 

From William: I need to provide 712 cubic feet to water storage capacity.
If I use 15 inch diameter pipe, what would the length need to be
to provide the capacity? Answered by Stephen La Rocque. 





The combintion of a bike lock 
20070701 

From Tricia: I have a bike lock that I know the numbers 3, 6, 8, & 9 are part of the combination, but I can't remember the order. What is the calculation to get all of the possible combinations. Answered by Stephen La Rocque. 





A sand base for a pool 
20070701 

From Clark: I am adding sand for a base for a pool. It is 20' round and I would like the sand
to be 2" deep. Can you tell me how many cubic feet that would be?
Thanks! Answered by Harley Weston. 





A cylindrical slab of concrete 
20070630 

From Kenn: I have a tank that needs a base of cement put in it. I dont know how to do this. The tank is 8 feet across and I want the cement to be 5 or 6 inches deep. Can you please tell me how much cement I need to do this. Answered by Harley Weston. 





The lock code for my phone 
20070630 

From Amanda: okay so i forgot my lock code for my phone its four digits but i know it doesn't have a 1 or a 0 in it so it has to be from numbers 2 to 9 i need to know all the four digit combinations asap cause i cant use my phone till can someone please help me Amanda Answered by Penny Nom. 





Edging around a pool 
20070626 

From Celeste: I have a 27ft. above ground pool. I want to put edging around it but do not know how many feet of edging I need. Can You help? The edging will be approximately 2 feet away from the pool. Answered by Penny Nom. 





How many tons of sand? 
20070619 

From Richard: I need to know how many tons of sand it would take to fill a container 20 feet
long, 20 feet wide, and 6 inches deep. I am not sure of the makeup of the sand as
far as dry, loose, wet, etc. If you could give me calculations of all the variants it
would be appreciated. Answered by Stephen La Rocque and Penny Nom. 





How fast was he going? 
20070603 

From Mary: if a motorcycle left a 63 foot skid mark before hitting a car how fast was he going ? Answered by Penny Nom. 





The surface area of a fire hose 
20070526 

From Vanessa: Why do we need to find the surface area of a fire hose (cylinder). Answered by Stephen La Rocque. 





Mulch price comparison (price per cubic yard versus price per cubic foot) 
20070523 

From Dianna: This is a 2fold question. I am getting some mulch that is measured in 1 cubic yard for $25.00.
Walmart has a 2 cubic bag for $3.00. I need to cover a 376 sq ft area. I need to know which is
the best deal and how much I need to buy to cover the 376 sq ft. Answered by Stephen La Rocque. 





How many tons of dirt is this? 
20070523 

From Deb: I need to know how many tons of dirt(6 inches deep)would it take to cover 8 acres? Answered by Stephen La Rocque. 





Lot acreage 
20070521 

From Sherri: I have a lot that is 2565 x 1056 x 2636 x 285 that is roughly in the shape of a triangle, with the small strip on the top of the triangle, that I would like to figure the sq. footage for. Could I draw a line from one corner on the top to the opposite corner on the bottom and get the area of those two triangles, then add that together to come up with the sq. ft.? Answered by Stephen La Rocque. 





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 of sand to volume (a sand ceremony) 
20070521 

From Linda: I'm getting married. We are having a sand ceremony. The empty bottle we are using holds 800ml. I have bags of colored sand. Each bag is 30g. There is 7 people participating in this ceremony. What I need to find out is how many grams of sand i need for 7 people to participate to fill this jar. Answered by Penny Nom. 





Parabolas in the real world 
20070518 

From Katherine: Hi, my name is Katherine, and my mean old math teacher just assigned us a test in which
we have to write two examples of how parabolas are used in the real world, each one page
single spaced, size 12!! I know you have already answered some questions like this, but
I still don't understand the whole baseball thing, and any other way parabolas are used.
And how I can write a whole page on it. But that's my problem, not yours, I just need help
with a little explanation on how parabolas are actually used today. I know this might be kind
of confusing for you, but imagine how it is for me!! Answered by Stephen La Rocque. 





Buying topsoil 
20070516 

From Claudia: I am trying to figure out if it is cheaper to buy topsoil by the bag (one 40lbs bag for $1.66) or having it delivered for $60 for 4 cubic yards. Answered by Penny Nom. 





4 digit lock 
20070516 

From Kathy: Hi,
My name is Kathy and I'm a REALTOR, I have 2 different lockboxes that
I cannot remember the combinations for, so what I need is all the
different combinations for 4 digits that cannot be the same, i.e. 0123.
Can you help me out? I would hate to throw them away as they cost
about $30 each.
Thank you,
Kathy Answered by Stephen La Rocque. 





Volume of a wedge 
20070514 

From Mark: We need to fill in dirt along a 75 foot long fence, 3 feet out , statring at 6 inches agaisnt the fence, sloping to 2 inches at the grass. I am trying to calculate the volume to order enough cubic yards of dirt to fill this. Answered by Stephen La Rocque. 





Lot size / acreage (more than three sides) 
20070511 

From Martha: What is the lot size of the following dimensions equivalent to acre.
141.85 x 52.55 x 217.63 x 38.89 x 68.08 Answered by Penny Nom and Stephen La Rocque. 





Pattern for a truncated cone 
20070511 

From Mike: I have been trying to get this cone flat so I can build this column. Can you please help me so I can figure this out? Thanks for your help. Answered by Stephen La Rocque. 





Area of a pentagonal lot 
20070509 

From Mimi: I would like to know the square footage of a pentagon with the
following measurements:
Property is .43 of an Acre
Front: 57.11'
NW: 105.78'
S: 120'
SE: 145'
E: 102.86'
I don't want you to try to show me how to work thru the problem since
I will never comprehend it. For some reason, I am unable to perform these
kinds of equations. I will greatly appreciate your help. Answered by Penny Nom. 





Cubic feet of sand 
20070509 

From Paul: I have an above ground pool that is 585 sq feet. I want to cover the bottom in 3 inches of sand. The sand supplier says I need about 6 cubic yards, based on your prior answers on this subject. I come up with 1.8 yards. What is the correct amount? Answered by Stephen La Rocque. 





Uses of pi 
20070508 

From Kari: How is pi used in real life? Answered by Penny Nom. 





Square footage of a lot 
20070503 

From Linda: I have two lots which I am trying to calcuate the square footage of
one lot is 50 x 285.72 x 50 x 270
2nd lot is 50 x 285.72 x 50 x 277.61
Any help would be appreciated. The answers would be GREATLY
appreciated. Answered by Penny Nom. 





Reverse Calculation of GST and PST in Quebec 
20070503 

From Derek: Could you please tell me how to figure out the PST and GST paid on an item.
Example: I paid $10 total (including taxes) and the GST is 6% and the PST is 7.5%, HOWEVER, in Quebec, we pay the PST on the subtotal+GST.
Thanks, Derek Answered by Stephen La Rocque. 





The grade of a shoulder 
20070428 

From Robert: I am building a road with a 1.2 meter shoulder. The plan calls fo a 6% shoulder grade. When I use my metric calculator I come up with a different answer when I multiply 3/4 of an inch by 1.2 meters and when I multiply 1.2 meters by .06%? Answered by Penny Nom. 





The size of a freezer 
20070423 

From Jacqui: How many can packages can fit? I have a freezer that is 7cf. But
it contains a little tray component. The freezer measurements without the
tray is(bear with me, I'm not good with LxWxD) 23 across x 16 W x 25
deep (I'm assuming depth) and the tray is 8 across x 16 w x 15 D. We are
trying to see how many 9 L x 6 W x 3.5 D packages can fit in the freezer.
Please help me. I'm getting app. 60. I need 84 to be able to fit. Answered by Penny Nom. 





Constructing an octagonal deck around a circular pool 
20070420 

From Cliff: [I am building an] octagonal desk encompassing 17 foot diameter circle for pool.
I have seen other octagonal calculations but none of these tell me how much allowance for a circle to fit within the octagon without losing the circle edge can anyone help
thanks cliff Answered by Stephen La Rocque. 





Relating volume to depth in a cylindrical container 
20070419 

From Dan: I have a cylindrical polyethylene rain barrel 23" in diameter and 35" high. If I've calculated correctly thus far, its volume is:
14, 547.49 cubic inches (or 8.418686 cubic feet or 0.31 cubic yards)
and could, ideally, contain 62.6 gallons of rain water whose weight would be 525.32 lbs. (62.4 lbs./cubic foot X 8.418686).
I'm having difficulty relating inch depth markings on the side of the barrel to volume capacity; i.e., how many inches in depth
in a cylinder of the size given would = how many gallons (or quarts) of water. The barrel stands upright on its end and is, thus, 35" high
when oriented in this fashion, much as a 55gallon oil drum appears when similarly stowed.
Dan Watley Answered by Stephen La Rocque. 





Fractions! Fractions! Fractions! 
20070416 

From Maria: Why are fractions important for:
1) The study of Mathematics
2) Real life Answered by Haley Ess. 





Principia Mathematica 
20070412 

From victoria: i need help making a poster on emilie du chatelet a great mathematician can you describe
the newton principia because i know that she worked on it
thanks,
victoria Answered by Stephen La Rocque and Penny Nom. 





A wooden hexagonal pyramid 
20070412 

From David: Im trying to form a hexagonal pyramid out of plywood and need to know the height to the center point of the pyramid. I want to use standard 4x8 sheets of plywood and split them diagonally. Then with the resulting triangles combine them to form one triangle. Then i want to accumulate 6 of these triangle total and put together to form a hexagonal pyramid. Answered by Stephen La Rocque. 





An arc shaped groove into a peice of metal 
20070412 

From daniel: hello i work at an engineering workshop the other night i was asked to machine an arc shaped groove into a piece of metal the cord length was 6 mm and the height from the middle of the cord to the arc was 1mm i was hoping to find the diameter of the cutter needed to do the job and also the formula to work out how to find the diameter. i believe it is 10mm dia thankyou for your time and knowledge Answered by Stephen La Rocque. 





Yards of sand in a ton 
20070409 

From Teresa: how many yards of sand are in a ton and how many yards of limestone does it take to make a ton Answered by Penny Nom. 





A cabinet with an arched front 
20070409 

From Joe: I am building an arched front cabinet that is 71 inches wide, 12 inches deep at both ends
and 16 inches deep at the center. To accurately build this cabinet I need to known the radius of
the circle that would form that arch.
Thanks,
Joe Answered by Penny Nom. 





An arched opening for a large doorway 
20070408 

From Richard: I am trying to build an arched opening for a large doorway...I know the vertical sides of the opening to be 8'9" from the floor to the lowest point of the arch on each side...I know it is 15 1/2" from the center horizontal point to the top of the arc...I know the vertical sides are 11'11" apart...what I need to know is the radius to create the proper arc. Can you help? Answered by Stephen La Rocque. 





The area of a parcel of land 
20070403 

From Ricky: I need the attached land parcel (#0436) converted to acreage.
This would be of great help to me.
Thanks,
Ricky Answered by Penny Nom. 





A "claw setting" for a gemstone 
20070330 

From Stephanie: I'm trying to make a cone out of a flat sheet of metal for a "claw setting" for a gemstone.
The cone must be 8mm wide at the top and 11mm long tapering to a point. But because the prongs must be cut out of the top the cone should not start to taper for a length of 3mm from that top 8mm. The 3mm prong is then bent over the 8mm stone. That probably doesn't make enough sense. But I don't know how to explain it. If it helps a claw setting is the very common prong setting for engagement rings or earrings. Please help as soon as possible as this is a commissioned piece for someone and I'm running out of time. I don't remember any math really from high school so please make the instructions really easy to follow. Thank You!! Answered by Penny Nom. 





How many tons it will take to fill in this area 
20070329 

From Amy: I have to fill an area with millings (crushed stone). The measurements are 14 foot long, 14 foot wide, and a depth of 6 inches. How do I find the square footage and how do I convert that into tons?
I need to know how many tons it will take to fill in this area. Answered by Penny Nom. 





6 team schedule for softball 
20070329 

From Angie: I have 6teams that can only play 3 days a week. Each team must get 18 games in for the season. I have to split them being the home team and the away team sometimes. Answered by Penny Nom. 





How many yards of gravel do I need? 
20070328 

From Joel: I am constructing a French drain 100 feet long x 6 inches wide by 18 inches deep. Within this trench will be a 4" diameter pipe which will be surrounded by washed gravel. How many yards of gravel do I need? Thanks! Answered by Stephen La Rocque. 





The volume of a hopper 
20070323 

From amitesh: Let me know how to calculate the tonnage of hopper / bins / chutes of different sizes and dimensions. Answered by Penny Nom. 





Examples of algebra used in life 
20070321 

From Arianna: i need to find about 5 different examples of algebra used in life, and im not sure where to start. does anyone have any suggestions as to topics that i should choose for my project?
thank you so much for all of your input.
Arianna Leigh Answered by Penny Nom. 





28 golfers playing golf over 7 days 
20070320 

From ian: I have 28 golfers playing golf over 7 days
I would like everybody to play with each other at least once
Is there a schedule?
Thank you
Ian Answered by Penny Nom. 





How may litres are in my fish pond 
20070318 

From beryl: I need to work how may litres in my fish pond.
I have measures it in two sections because of it shape.
One section is 1600w, 1100L, 540D.
the other section is 1060W, 1800L, 380D.
Thank you
beryl Answered by Penny Nom. 





Percentage markup 
20070316 

From Debbie: What formula or formulas do I use if I want to ultimately charge a customer $300 for a service, but need to factor in a 15% commission for a sales rep, $20 to cover the cost of our overhead, the cost of a $25 coupon that we will be sending to the customer to apply to future services. In other words, what amount do I initially quote the customer to be able to cover these costs? Answered by Stephen La Rocque. 





The area of a property 
20070314 

From Greg: Hi my name is Greg. I have a piece of property I am trying to buy,
but need to find out the square feet of it first.
The four sides are unequal lengths and none at a right angle or
parallel. Here are the measurement in feet.
The base of the square is 29.12 feet in width.
The right side of the square is 44.33 feet high.
The top of the square is 28.80 feet in width.
The left side of the square is 46.20 feet high.
I have not done this math in ages and really need your help. Answered by Harley Weston. 





A truncated cone 
20070310 

From Russell: Hello, I have attempted to use two of your answers already given and had no real success. This young lady is making a cat food dispenser using a truncated cone. The top of the cone as a diameter of 5 inches with a height of 6 1/2 inches and diameter of 3 inches for the bottom.
Could you please map out a solution for the both of us to understand? Thank you so much for your time and for this wonderful service.
Russell Answered by Penny Nom. 





How many barrels would this container hold per inch? 
20070310 

From LaDonna: My container is 50" across and 40.5' ft. long. I believe it would hold 140 barrels. If measuring, how many barrels would this container hold per inch? Answered by Penny Nom. 





What is pi? 
20070309 

From Billy: What is pi? Answered by Jaymi Peterson and Sara Ulmer. 





A steel pipe pile 
20070308 

From Sean: Need to fill a 18" OD x 60 feet steel pipe pile with a wall thickness of 1/2" What is the amount of concrete I need in order to fill? Thank you Answered by Stephen La Rocque. 





A fountain as a parabola 
20070308 

From Emily: I have to do a math project proving that something in real life is a parabola. I really need some help here because i don't know where to start. I want to do it on a fountain and prove it's a parabola but how do i do that? I would really appreciate it if you could help Emily Answered by Stephen La Rocque. 





Chords and arc lengths 
20070308 

From Angela: my dad, who is a welder, asked me a question pertaining to chords and points on an arc to which I cannot for the life of me find an answer or an equation. if you could help, it would be much appreciated. I am sending an attachment of the problem. Answered by Stephen La Rocque. 





A metal shroud for a outdoor fireplace 
20070306 

From Arnold: I am making a metal shroud for a outdoor fireplace, it is basically a lampshade type pattern,like the bottom of a cone.The top has to be 6 inches to fit the 6 inch stovepipe,and the bottom will be a 24 inch circle. the sides will be 18 inches in length.With the cost of the sheet metal,I can only afford to cut this out once,can you help me with the pattern ? Answered by Penny Nom. 





One acre of water, one foot deep 
20070305 

From Jeff: If you have one square acre of ground flooded with one foot of water and a pump that pumps 1000 gallons a minute how long would it take to drain the one acre of ground? Answered by Penny Nom. 





The volume of a trailer 
20070304 

From Ron: I just can not seem to work this out, i think it is old age catching up with me, I am buying a trailer that is 25 feet long 7.5 foot wide and with 4 foot sides and i am trying to work out how many m3 it will hold can anyone help. Thank you in advance for any help. Regards Ron Answered by Penny Nom. 





A long narrow cone 
20070304 

From Amy: I am an art student making a piece of jewelry out of a flat metal sheet. I'm trying to make a long narrow cone that's roughly 3 1/4" long and just slightly under 1" wide at the base. Since I'm no math wiz, I'm having a really hard time. Please help. Answered by Penny Nom. 





Slope 
20070302 

From Lacey: My algebra 2 class is researching graphing and slope and we would like to know how we use graphing and slope in everyday life. So if you could get back to me with some real world examples i would really appreciate it. Thanks for your help! Answered by Steve La Rocque, Penny Nom and Sara Ulmer. 





How many yards of concrete? 
20070228 

From jeremy: I need to figure how many yards of concrete to use. I work for an asphalt company, and we are expanding into concrete. Currently we measure everything in sq. ft. So we came up with 6,960 sq ft of concrete to remove and replace. Currently there is 6" of concrete, and 2" of bedding material. We would like to replace only 4.5" of concrete, the rest in bedding. Here is how I figured, am I correct. 6,960 Sq ft (to simplify I made the Sq ft 350 X 20 ) 350 ft X 20 ft X .33 (1/3 ft or 4") = 2,310 cubic feet 2,310 cb ft / 27 = 85.55 cubic yards Is this correct? Answered by Penny Nom. 





How many cubic yards can my truck hold? 
20070225 

From Mike: If I have a dump truck that has a box that is 14' long sides that are 3.5' high and the width is 7.5' wide... how do I figure out how many cubic yards this truck can hold? Answered by Steve La Rocque, Penny Nom and Melanie Tyrer. 





Circles 
20070222 

From Erika: I have a research paper due on real life uses of conic sections I've looked through all your conic topics and uses of them, but and i cant seem to find real life uses for circles. What are real life uses of circles? Answered by Penny Nom. 





What jobs involve using conics? 
20070221 

From Nicki: What jobs involve using conics? Answered by Penny Nom. 





Things that are shaped like a parabola 
20070214 

From carra: i can't find other examples of things that are shaped like a parabola except for bridges.............. Pls. help it is due tomorrow. thank you very much:) Answered by Steve La Rocque, Penny Nom and Walter Whiteley. 





How many gallons will it hold? 
20070127 

From Taye: I am building a aquarium for my daughter, It is 6 feet long 24 inches high and only 5 inches wide. How many gallons will it hold? Answered by Stephen La Rocque and Penny Nom. 





Splitting a 5 acre piece of property 
20070125 

From John: I have a 5 acre piece of property that I wish to split into 5 individual 1 acre parcels. The 5 acre parcel 1s 660 feet in length and 330 feet in width. The first two parcels are 264'x165', but I am asking for help getting the perimeters of the last 3 lots, one of which is a irregular pentagon. All of the one acre parcels must have an area of 43,560 square feet each. Answered by Penny Nom. 





As many player combinations as possible 
20070118 

From Ken: I coach a 5th grade basketball team with 12 players. I'd like to come up with a way to get as many player combinations as possible with two teams of 6 so that the makeup of the teams is different each time. An example would be: Players 16 on one team and players 712 on the other. Then I could have 1,3,5,7,9,11 on one team and the evens on the other. Then 1,2,6,7,9,10 on one team and the rest on the other. Can you help set something like this up? Answered by Chris Fisher. 





An octagonal bird house 
20070113 

From Soren: I'm in the process of building a birdhouse that is an octagon (based on previous questions, looks like that's a familiar tune). The essential elements are known, but I get stuck when trying to determine the angle for the cuts that would be made to the thickness of the wood so that they all fit together when assembled. Each octagonal section is 7 inches in width and the peak of the roof will be 2 inches higher than the sides. My sense is that the angle cuts that need to be made to the 'height' of each piece of wood. By height I mean the thinnest part of the wood that is neither the length nor the width to use colloquial terms. While it's clear that a slight angle is needed, it would seem that the angle would necessarily change as the distance from the top of any one side to the peak changes. Please advise if more clarification is needed. The 2 inches is random and can be changed if more convenient. Whew! Answered by Harley Weston. 





Calculating rainwater volume 
20061230 

From Mark: Trying to calculate 1" rainfall on a 1000 sq' roof=how many gallons of water would collect in our cistern. Answered by Stephen La Rocque. 





An octagonal birdhouse 
20061230 

From Verner: I am building a octagon birdhouse,what degree would I cut each side of each piece of wood to assemble the birdhouse? Answered by Penny Nom. 





The proof of inequality by mathematical induction 
20061207 

From Carol: S(n) = 2^n > 10n+7 and n>=10 Answered by Stephen La Rocque. 





I have to design a lettering on corrugated plate 
20061129 

From Tim: For a client of mine I have to design a lettering on corrugated plate. The lettering has to appear "normal" when viewed from the front (100%) I am so far now to consider the shape of the plate to be two halves of an oval/ellipse. What I would like to know is a way to calculate the percentage in which I have to "stretch" my design in order to let it appear "normal". Answered by Stephen La Rocque and Penny Nom. 





The Fibonacci sequence 
20061121 

From Ross: Let f0 = 0; f1 = 1,... be the Fibonacci sequence where for all n greater than or equal to 2 fn = fn1 + fn2. Let Q = (1+square root of 5)/2. Show that for all positive n greater than or equal to 0, fn less than or equal to Q^(n1). Answered by Penny Nom. 





Composition of functions 
20061119 

From RJ: Let f0(x) = 2/2x and fn+1 = f0 o fn for n greater than or equal to 0. Find a formula for fn and prove it by mathematical induction. Recall that o represents function composition. i.e., (f o g)(x) = f(g(x)). Answered by Stephen La Rocque. 





Conic sections 
20061119 

From Joyce: My son has a project on conic sections. I need the following information on Parabola, Circle, ellipse,and hyperbola. He can't find the following information for each conic section: equations with explanations, four uses for each shape and Shape explanation. Answered by Penny Nom. 





Induction 
20061116 

From John: Find a formula for 1/(1x3)+1/(2x4)+1/(3x5)...+1/(n(n+2)) by examining the values of this expression for small values of n. Use mathematical induction to prove your result. Answered by Penny Nom. 





Motorcycle expansion chamber design 
20061114 

From David: I'm interested in calculating cone information regarding motorcycle expansion chamber design for example. I guess it's called a truncated cone, from what I've read so far. If I know the center line height, small radius, and large radius of a truncated cone then, how can I calculate the angle (included angle?) the cone forms? I'd like to know the variations of the formula so I can calculate for angle, or length, or one of the diameters if I know the other two measurements. Answered by Stephen La Rocque. 





Some applications of conic sections 
20061113 

From Burt: how are circles, ellipses, and hyperbolas used in everyday life Answered by Penny Nom. 





A proof by induction 
20061106 

From Zamira: i have a problem with this mathematical induction: (1^5)+(2^5)+(3^5)+...+(n^5) = ((n^2)*((n+1)^2)*((2n^2)+2n1))/12 Answered by Penny Nom. 





ESL and mathspeak 
20061103 

From Matt: My name is Matt and I am an ESL teacher in Korea. Recently I have begun tutoring a student who will be going to Canada soon as a 9th grade student. She is a very capable student and is concerned that her mathematical abilities outstrip her ability to communicate in English. I am writing mainly to inquire what level of mathspeak I should teach to this student. For instance: should I be explaining geometric terms, or simply algebra? And if algebra, should I include complex numbers and the quadratic formula? If there are things that she will be taught in Canada, I'd prefer her to learn them firsthand from a math teacher. However, knowledge that she will be presumed to have I would like to teach. Answered by Karen McIver. 





Ratios, proportions and medicine 
20061025 

From Steven: I don't understand why we need to learn about ratios and proportions because i want to become a doctor and i don't know if i'll ever use this type of math. Answered by Penny Nom, Claude Tardif and Walter Whiteley. 





How do we use fractions in every day life? 
20061019 

From Tori: I am doing fractions in class and we need to write a paper about them. So my question is:"how do we use fractions in every day life?" Answered by Claude Tardif. 





An octagonal room 
20061018 

From Rick: I am a cabinetmaker, and I have a client who has an octagonal room which he would like to be used as a walkin closet. Each side of the octagon is 60" in length. Each wall section is to have a 24" deep cabinet installed on it. I am trying to figure out the width of each cabinet allowing for a 3" space between cabinets at the front corner. Answered by Stephen La Rocque. 





The focus of a parabola 
20061001 

From Lily: I have a mathematical assignment which includes applications of parabolas, hyperbolas and ellipses in the real world. I have been searching the internet and now I am ware that most of the applications of parabolas have a connection with what people call "the focus". However, I do not think I clearly understand what "the focus" of a parabola is. Would you please explain it to me? Answered by Penny Nom. 





I need to cut an octagon 
20060923 

From Freddie: I have a 48 inch square piece of wood that I need to cut into an octagon, help. What's an easy way to just measure and cut it. Answered by Penny Nom. 





Constructing a cone 
20060920 

From Suresh: i want to know the required size of plate for cone rolling,sizes are 2950mm is bottom dia,894 is top dia and 600 is height.I have already read u r answers but i little bit confused ,harely and sue have given useful answers but when i worked both method the required plate size is different. so i like to know which method is easy and correct.and also i like know whether it can be rolled without segment my rolling machine width is 1500. Answered by Penny Nom. 





The square footage of my property 
20060917 

From Jack: I have been trying to calculate the square footage of my property, without success. The measurements are below.
Is there a simple formula that can be used based upon the outside parameters? Or, is there a simple way to calculate the square footage? Answered by Stephen La Rocque and Penny Nom. 





A perpendicular intersection of two barrel vaults 
20060721 

From Neal: I'm wanting to build a series of architectural models of different roman and medieval buildings out of cardboard. Once I have perfected the models I want to print them out on card stock so that school kids (or anyone else) can make the buildings.
A feature of many of these models is the cross or groin vault (a perpendicular intersection of two barrel vaults).
A single barrel vault is easy to imagine as a plane (a rectangular piece of cardboard) that will be folded into a semicircular arch.
The intersection of a second barrel vault and this one is presenting me with problems. The second plane needs to have an ellipse cut into it so that when it is folded into the arch, it will mate up with the curve of the first barrel vault.
Given that the two pieces of card have identical widths (and therefore identical arcs in cross section) is there a way to calculate the ellipse that needs to be cut so that it can be cut before the second arch is folded? Answered by Edward Doolittle. 





I have a ditch how many tons of dirt will it take 
20060625 

From Scott: I have a ditch 200 feet long 10 feet wide and 5 feet deep.How many tons of dirt will it take to fill it? Answered by Stephen La Rocque. 





Designing a garage 
20060608 

From A builder: I'm currently designing a garage and came upon this interesting math problem. I've tried using various methods to solve it but have so far been unsuccessful. I've included a picture as its far easier to show you my question than explain it verbally. I realize it could be done by trial and error but i'm looking for a real solution. Answered by Stephen La Rocque and Penny Nom. 





The area of part of a circle 
20060529 

From Larry: need to find area of a circle between a given line (cord) to the circumference of the circle (see attachment). I often review blue prints of homes and many times have to know the area the home. Answered by Stephen La Rocque and Penny Nom. 





A triangle problem 
20060518 

From Jim: Right angle triangle with a hypotenuse of 20 units.
Square inside the triangle with sides of 4 units, the square shares two sides with both legs of the triangle, and the corner touches the hypotenuse limiting the triangles size. Answered by Penny Nom. 





The volume of water in a sphere shaped water tower 
20060514 

From Dan: I work in the water industry, providing automatic controls for water systems. I was wondering if there was a formula for calculating the volume of water in a sphere shaped water tower? With the use of a pressure gauge we know the elevation of zero water {the bottom of sphere) and the overflow elev. (near the top of sphere) I would like to calculate how many gallons are at any elevation in between. Answered by Stephen La Rocque. 





Superimposing images 
20060330 

From Laurie: I am a parent and trying to find real world applications for the math strand that includes superimposing one item on another to determine identical. The Alberta strand is match size and shape of figures by superimposing one on top of the other. I am trying to find a way to put this into context for everyday life. Any ideas? Answered by Penny Nom. 





The area of a block of land 
20060326 

From Ronald:
I have a building block of land with four unequal sides and only one right angle. I want to know the total area (in metres) and how the calculations were carried out.
The four sides are: Rear of property: 9.14 metres
left side: 36.9 metres
Right side: 32.61 Metres
front to street: 27.43 Metres
The front to street and right side constitute a right angle. but there are no others. Answered by Penny Nom. 





Quarts, liters cubic yards and soil 
20060319 

From Kathy: I am trying to find out how many quarts of dirt there are in a yard of dirt. The local flower store sells bags of dirt that are 20 quarts or 22 liters for $1.25 and another store sells a yard of dirt for $25.00. Which is the better deal? Answered by Penny Nom. 





Building a flower bed 
20060317 

From Bobby: I am building a flower bed 60 ft long by 8 ft wide by 3 ft deep. How much dirt will it take to fill it with top soil/dirt. Answered by Penny Nom. 





Cubic yards of dirt 
20060128 

From Greg: How many yards of dirt do i need to cover an area of 1000 ft long, 20 ft wide and 3 inches deep Answered by Penny Nom. 





How do you find the angles in a triangle? 
20060127 

From Keith: How do you find the angles in a triangle if you know the lengths of the sides? Answered by Chris Fisher and Penny Nom. 





The angles in a hexagon 
20060122 

From Linda: My problem is in relation to wood and making a six sided object from it. On my saw, there is a place to set the angle to which you wish to cut. I cannot for the life of me, figure this out. I am starting with a piece of plywood (1/4" x 6" x 18") and need to know what the angle degree would be to make each of the sides match perfectly to form a hexagon. Trial and error just is not working. Can someone help me? Answered by Penny Nom. 





An irregular octagon 
20060120 

From Robert: I am building a poker table which is in the shape of an irregular octagon. I know the table measures 72 inches long and 48 inches wide with two parallel straight sides of equal length and six smaller sides of equal length ( three at each end of the table), what I don't know are the lengths of the any of the sides. Answered by Harley Weston. 





Barrels of oil in a tank 
20060109 

From Francis: How many barrels of oil (42 gallons of oil in one oil tank) would there be in an oil tank that was 15 feet tall and 10 feet across? Answered by Penny Nom. 





The area of an octagon 
20060103 

From Nikki: I want to figure out the square footage of an octagon. i have 8 panels that are 24" wide. Its for my dogs and i wanna know how much room they'll have. Answered by Penny Nom. 





A probability question which resulted from a game of Yahtzee 
20051231 

From Robert: Could someone please assist me with this probability question which resulted from a game of Yahtzee we were playing in Melbourne, Australia on our holidays.
The object on this turn was to throw a “large straight” which is 5 numbers in sequence from 5 dice numbered 1 – 6. A player initially throws all 5 dice and then selects those dice they want to throw again for a further two more times. In this instance the player on their first throw, threw a 1,2,3,4 and 6.
Question: What is the respective probabilities of gaining a straight if they were to –
a) put back say the 6 and try and throw a 5 on the two further throws or…..
b) put back the 1 and 6 and try and throw a 1 and 5 or 5 and 6 on the two further throws bearing in mind that if one of the numbers was a 5 on the second throw they could hold that number and try for a 1 or 6 on the third throw.
I would be most appreciative if someone could assist in showing me how to calculate the probabilities particularly in the second instance (b). Answered by Penny Nom. 





Why do we bother learning prealgebra and algebra 1? 
20051223 

From Priya: My students always ask "Why do we bother learning prealgebra and algebra 1?" and I haven't found an answer to satisfy them yet. Can you help me? My students are from grade 9 to 11. I have tried giving them real life examples in each topic but it just feels like they are not satisfied!!! Answered by Penny Nom. 





Cubic yards of fill 
20051223 

From Mike: And I have a question in regards to the amount of fill needed to bring a vacant lot up to "grade level".
The lot is 112' x 87' and I need to bring in fill to elevate the finished level up 4'. Answered by Penny Nom. 





Percentages in our daily life 
20051223 

From Naina: what are the uses of percentages in our daily life Answered by Penny Nom. 





A sheet metal cone 
20051205 

From Laura: I am an art student and in the process of making a cone out of sheet metal. I am unable to work out the template I need to produce my final cone. The dimensions I have are that the final cone will be 58mm high and will have a diameter of 102mm. Answered by Penny Nom. 





How is trigonometry applied to everyday life? 
20051203 

From Yadira: My question is how is trigonometry applied to everyday lives and functions. Ex: Builders use it but how and what are some examples of the trigfunctions or formulas that they use? Answered by Harley Weston. 





Area of a lot 
20051203 

From Ben:
How do you calculate the area of the following Lot?
I figured the following angles from the deed, which read:
N 86 degrees, 45 minutes E, for 322 feet.
S 10 degrees, 30 minutes W for 113 feet.
N 84 degrees, 30 minutes W for 368 feet.
N 50 degrees, 42 minutes E for 76 feet.
N 40 degrees, 40 minutes E for 15 feet.
There is a discrepancy between two surveyors and I'd like to figure out how to calculate the Area of such a shape. Answered by Harley Weston. 





The sides of an octagon 
20051102 

From Royce: I understand there is a simple calculation to determine the sides of an octagon when you know the distance across the parallel flats. something like .447 . can you help? Answered by Penny Nom. 





A slump cone 
20051027 

From Wendy: we are trying to make a slump cone (used to measure the slump in concrete). It has dimensions of 8" diameter on the bottom, 4" diameter hole on the top and a height of 12".
Please help, it is getting frustrating. Answered by Penny Nom. 





How many cubic yards of dirt will be needed? 
20051027 

From Mike: We are filling in a hole left by the removal of an aboveground pool that was dug into the ground. The diameter is 25' across and the depth is 5'. I wondered how many cubic yards of dirt will be needed to fill this hole. Answered by Penny Nom. 





A conical hat 
20051022 

From Manish: I need to make a conical hat for my daughter's upcoming fancy dress, the circumference of the base(hollow) is 50 cms,the height of the cone is 30 cms,what should be the dimensions of the paper which will make a cone of the beforementioned dimensions? Answered by Penny Nom. 





Labour efficiency 
20050823 

From Rob:
The problem, on the surface, seems very simple and yet has created some controversy among a group of accountants. The problem itself has to do with labour efficiency rates and only involves two variables; standard working hours, and actual working hours. The difficulty lies in deriving an efficiency % from these two numbers.
Standard working hours or the targeted number of labour hours required to produce one widget, which I will represent as "s". Actual working hour or the actual number of labour hours require to produce one widget, which I will represent as "a". Labour efficiency I will represent with "E". The prevailing calculation with which I have a problem with is this:
s/a=E or if s=3000, and a=4000 then 3000/4000=75%
What bothers me about the calculation is that the standard hours get represented as a percentage of the actual hours and in my opinion changes the focus of the calculation from standard or target, where it should be, to the actual hours. I cannot define why, but this just seems inherently wrong to me.
The calculation that I use:
(1+((sa)/s))=E or if s=3000, and a=4000 then (1+((30004000)/3000))=66.67%
My calculation is like a %change from standard calculation. However, there is something that also concerns me about my calculation.
If you substitute 100 for a and 50 for s, then you come to a quandary, because if you plug those numbers into the second equation the result is of course zero % efficient which doesn't sit right with me either. If you plug them into the first calculation you get 50% efficiency which doesn't really seem to work either, because you require 100% more hours to do the same work in this case. ???
Is the first calculation correct? Am I missing something altogether? Are both calculations off base? Answered by Harley Weston. 





Framing an arched wall 
20050812 

From Mike: I'm framing a building wall with a curved (arcing) top section. The radius of the section is 74'6" with a height above finish floor of 16'0". The horizontal run of the arced section is 23' 1 1/2" with a low height above finish floor of 12'4". If I start with a 16' stud at the high end how long are the subsequent studs if they are on 16" centers? Short of laying this out on a tennis court how can I work out the lengths of the studs? Answered by Penny Nom. 





Digging a hole for a pool 
20050608 

From Debra: I need to have dirt hauled away from my built in pool and the haulers are asking me how many yards of dirt there is. How would I figure that out? It is a 24 ft round pool and 3 inches of soil depth was dug out. Answered by Penny. 





An octagonal deck 
20050607 

From Scott: I want to build a octagonal deck. The wood I am using are cut in 8 foot lenghts. What I want to know is if the sides of the octagonal are 8 feet, what is the diameter. Also what are the angles of each side? Answered by Penny Nom. 





The volume of a hopper 
20050528 

From Brian: I would like to know the volume of this rectangular hopper. can you help Answered by Penny Nom. 





Jobs relating to the topics of ratios and proportions 
20050517 

From Alexa: What are some jobs relating to the topics of ratios and proportions other than architects and map makers? Answered by Walter Whiteley. 





A wishing well 
20050328 

From Don:
I am building a wishingwell
out of pieces of 2by4. I have included a picture of a miniature version
of what I want. There are to be ten 2by4 pieces around the well and
I want the circle around the outside of the structure to have a diameter
of approximately 3 feet. How long to I cut the 2by4's to build the
wishingwell.
Thanks,
Don
Answered by Harley Weston. 





The volume of a stock tank 
20050313 

From Cord: I am a farmer and I have recently installed a new stock tank which is 1650" in circumference and 10' deep. How many gallons of water will it hold? Answered by Penny Nom. 





A 6 sided (hexagonal) pyramid 
20050122 

From Steve: im trying to make a 6 sided (hexagon) pyramid, from 6 triangles of 12mm plywood, i know all the angles to cut apart from the one one to join all 6 triangles together. Rough measurements are outer edge (A) of each triangle is 13cm's, length of other 2 sides (B&C) of triangle outside to center is 14cm's with a height of the whole thing together about 6cm's. Answered by Chris Fisher and Harley Weston. 





Quadratics 
20050105 

From Usman: Hi, in my Grade 11 Functions math class we have been assigned the task of finding jobs and careers related to quadratics, I have done many searches but have been unsuccessful, then I saw your website and emailed. I also have to use an example of a math problem that the job uses, then solve it, this will all compile on bristol board for a presentation. I would greatly appreciate it if you could send me some links and references of sources that refer to this subject. Answered by Harley Weston. 





An elliptical table 
20050103 

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. 





Modelling monthly temperature with a cosine 
20041225 

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. 





Proof by induction 
20041120 

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) = 2n1 x 3 (equation 1)
Equation 1 must be proven using mathematical induction. This is where I am having a problem. Answered by Penny Nom. 





Construction of a cone 
20041120 

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. 





Practical applications: parabolas and Pythagoras 
20041024 

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. 





Pythagoras in everyday life 
20041013 

From Tiffany: I was wondering if you have any reallife uses of the pythagorean theorem that you use in your everyday life. Answered by Penny Nom. 





The area of a lot 
20040929 

From Deb: I am trying to figure out how many square feet are in a piece of property. Start at Point Athen go 140 feet norththen 100 feet due eastthen 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. 





An Octagonal playhouse 
20040713 

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. 





How much loam to fill a hole? 
20040619 

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. 





Pi 
20040510 

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. 





A stained glass window 
20040329 

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. 





Volume of a fuel tank 
20040301 

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. 





Bundles of asphalt shingles 
20040124 

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. 





Cubic yards in a concrete wall 
20040118 

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. 





Inequalities 
20040108 

From Michael: How do you use inequalities in your job and in your everyday life? Answered by Penny Nom. 





Ratios and proportions 
20031231 

From Frank: I would like to know how you use 'ratios and proportions' in everyday life. Answered by Penny Nom. 





Factoring in 
20031216 

From Priscilla: How can you use solving by factoring in real life applications? Answered by Harley Weston. 





Math jobs 
20031212 

From Veronica: Do you know a couple of jobs I can get when I am older in Math? Answered by Harley Weston. 





Knitting gauge and felting 
20031027 

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 postfelting 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. 





Applications of logarithms 
20030916 

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. 





Slope 
20030720 

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. 





A geometry problem 
20030708 

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. 





How much soil will be removed? 
20030702 

From Amy: My site is 1230' (eastwest) by 1300' (northsouth) and we need to remove 2 feet of soil from the entire site, how much soil will be removed? Answered by Penny Nom. 





Area of a trapezoid 
20030413 

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. 





Uses of conic sections 
20030401 

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. 





A triangle and a circle 
20030321 

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. 





The origin of integers 
20030319 

From Travis: What are the real life usages of integers? Also what is the origin of integers? Answered by Harley Weston. 





A question on combinations 
20030306 

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. 





Excluded values 
20030222 

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. 





Filling in the back yard with dirt 
20030204 

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. 





Cubic yards in a gravel pile 
20030110 

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. 





The area of my lot 
20030107 

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. 





Decimals in everyday life 
20021124 

From Fritz: How do you use decimals in your every day life? Answered by Penny Nom. 





Clown has eight steps to climb 
20021105 

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, 32=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. 





Mathematics and Music 
20021101 

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. 





Integers in real life 
20021015 

From Rica: What are the real life usages of integers? Answered by Peny Nom. 





Math test 
20020628 

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. 





The best time to teach math 
20020310 

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. 





Proof by induction 
20020220 

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. 





Three bugs on a line 
20020212 

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 lefthand 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 3by3 square at the bottom lefthand corner of the grid. (b)
 Is it possible to remove all the pegs from the six holes closest to the bottom lefthand corner of the grid (the region indicated in the picture below)?
Answered by Claude Tardif. 





Parabolas 
20020203 

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. 





The size of a lot 
20020126 

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 
20020123 

From A teacher: How does young children's logico mathematical knowledge develop? Answered by Walter Whitely. 





A 1 m by 1 m square box in the xyplane 
20011215 

From Murray: Inside a 1 m by 1 m square box in the xyplane, 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. 





Integers 
20011202 

From Alison: How do you use integers in your everday life? Answered by Harley Weston. 





Ratios and proportions 
20011126 

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 3 dimensional 5 pointed star 
20011108 

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. 





Proof by induction 
20011016 

From John: Can you help me with any of these?  For any natural number n > 1, prove that
(4^{n}) / (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
x^{n} + x^{n  2} + x^{n  4} + ... + x^{n} >= n + 1. Answered by Penny Nom. 





Theme day 
20011014 

From A teacher: I woulld like a math theme for a theme day in a high school, grades 912. Our last theme was fractal fest. Answered by Penny Nom and Claude Tardif. 





Mathematical & conventional meaning of a word 
20011012 

From A student: What is the mathematical & conventional meaning of a word? Like the word Rational or Median. Answered by Penny Nom. 





Ratio and proportion 
20011010 

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. 





Percentage in our daily lives 
20011008 

From Natasha: What are the uses of percentage in our daily lives? Answered by Leeanne Boehm. 





Proof by induction 
20010930 

From Kyle: I'm trying to learn induction and I need to see how this done please help with this problem... 2^{0} + 2^{1} + 2^{2} +... + 2^{n} = 2^{n+1} 1 is true whenever n is a positive integer. Answered by Penny Nom. 





Don't worry too much about your difficulties in math... 
20010907 

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. 





Quadratics 
20010516 

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. 





A sequence of even terms 
20010429 

From A student: A sequence c is defined recursively as follows: c0 = 2 c1 = 4 c2 = 6 ck= 5ck3 for all integers Prove that cn is even for all integers. Answered by Leeanne Boehm and Penny Nom. 





Math Puzzle 
20010310 

From Vanessa: I have a math puzzle. I have been working on it for over 2 weeks. Here it is: use the numbers 125 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. 





Math game 24 
20010221 

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 
20010221 

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. 





Polynomials and exponents 
20010115 

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. 





Women mathematicians 
20010107 

From Kisha: Can you please tell me names of at least five female math teachers who changed history back then? Answered by Penny Nom. 





The pythagorean theorem in everyday life 
20010106 

From Josh: What are some ways that we use the pythagorean theorem in jobs, or even in everyday life? Answered by Claude tardif. 





Bridges and parabolas 
20001118 

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. 





Where will we use this in the real world? 
20001011 

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. 





Induction 
20000907 

From Joe Peterson: How do I prove by the principal of mathematical induction? 1.n+2.(n1)+3.(n2)+.....+(n2).3+(n1).2+n.1=(n(n+1)(n+2))/6 Answered by Paul Betts. 





Writing in Math 
20000605 

From Laurel: How can I incorporate writing into my math curriculum? Answered by Penny Nom. 





1+4+9+16+...n^2 = n(n+1)(2n+1)/6 
20000601 

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. 





Mary Fairfax Greig Somerville 
20000503 

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. 





Chisanbop 
20000419 

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. 





Math in various careers 
20000418 

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. 





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. 





Rule of 78 
20000322 

From Dan Baumgarten: Can you explain the rule of 78 and the reverse rule of 78? Thanks. Answered by Claude Tardif. 





Induction 
20000316 

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. 





Mathematical deduction and mathematical induction 
20000307 

From Espera Pax: What are mathematical deduction and mathematical induction, and what is the difference between them? Answered by Harley Weston. 





The positive effects of mathematics on human's thought 
20000302 

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. 





A roll of paper 
20000115 

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 famous mathematician 
19991012 

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. 





Logic and mathematical logic 
19991006 

From Polly Mackenzie: What is the difference between logic and math logic? Answered by Walter Whiteley. 





English to french maths words translators 
19990922 

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. 





Cognitive development as related to learning mathematics 
19990804 

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. 





Compound Interest 
19990701 

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. 





Computer use in mathematics classrooms. 
19990623 

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. 





Resources for realworld math activities 
19990326 

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 realworld careers? Answered by Jack LeSage. 





Primary Mathematics 
19990208 

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. 





Math and Writing 
19990121 

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 
19990119 

From Kim Brandson: I am trying to put on a Math Olympics for K5 students in my district. Any ideas? Resources? Suggestions? Answered by Jack LeSage. 





Fitting a Curve 
19990119 

From Kirk Doward: 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 nonlinear. 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. 





Touch Math 
19981109 

From Melinda Robinson: I am a contracted district substitute teacher for grades K8. 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. 





Human Calculator 
19980914 

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. 





Multiplying by Nine  Chismbop Style 
19980427 

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. 





Clock Arithmetic. 
19980309 

From Joann Dixon: What is clock mathematics? Answered by Patrick Maidorn. 





A Finite Math Question. 
19970907 

From Angela L.: How many threedigit numbers can be formed using only the numbers 1 to 7 if the number 2 must be included? Answered by Penny Nom. 





Mathematical Induction and the Derivative 
19970318 

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. 





What are fractals and are they of any practical use? 
19960626 

From Ron Lewis: What are fractals and are they of any practical use? Answered by Chris Fisher. 





An application of Pythagoras' theorem 
19960409 

From Mike Jones: We'd like to know what practical applications there may be for the Pythagorean theorem. Answered by Penny Nom and Maxine Stinka. 





Terminologie mathematique 
20101031 

From Adil: Bonjour ,
Pourriezvous m'indiquer les titre et auteur d'un bon dictionnaire
francais anglais de terminologie mathematique ?
Auriezvous egalement l'adresse d'un site web traduisant du francais
a l'anglais les termes ert expressions mathematiques ?
Merci par avance,
Adil Answered by PierreLouis Gagnon. 





Le terme suivants 
20080330 

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. 





Un problème de math 
20040910 

From Sophie: (V est en fait le signe de la racine carrée)
(3 / V27) x ( V75 ) = ??? Answered by Claude Tardif. 





Un problème mathématique 
20020423 

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. 

