







A circle with a circular hole 
20190311 

From Sue: My little one is wondering if a circle with a circular hole could be described as an irregular semicircle.
As it has 2 sides but is not the standard shape. Could you share your thoughts ?? Answered by Penny Nom. 





Three consecutive whole numbers 
20180622 

From whaha: the sum of three consecutive whole numbers divided by 4 is equal to 6. find the numbers. Answered by Penny Nom. 





Gauss' Addition of whole numbers. 
20180430 

From Brad: I found this on your site. Question: what is the sum of the first 100 whole numbers??
Is there a different formula if the numbers begin at a number other than one? For example
What is the series I want to add is goes from 7  53? Answered by Harley Weston. 





The wholesale price given the retail price and the markup 
20180207 

From Matthew: Retail $99
Markup is 80%
What is the equation to find the original (wholesale) price (55)?
thanks Answered by Penny Nom. 





The number of truckloads to fill a hole 
20170618 

From Jennifer: How many full size truck bed pickup loads do in need to get to fill a hole that is 18' x 30' that is 4" deep? Answered by Penny Nom. 





A square peg in a round hole 
20170529 

From bill: bill wants to put a 2 foot square peg into a round hole What must be the circumference of the hole? Answered by Penny Nom. 





Filling three holes with stones 
20140820 

From mark: how many tonnes of hardcore/crushed stone would it take to fill
1 hole 9ft diameter 5ft deep
and 2 holes both 3ft diameter and 5ft deep 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. 





Three consecutive whole numbers 
20140313 

From Abhishek: Three consecutive whole numbers are such that if they be divided by 5,3 and 4 respectively, the sum of the quotient is 40. What are the numbers? Answered by Chris Fisher. 





A Holeinone on all four par 3's 
20130904 

From Robert: There are four (4) par 3's at a specific 18 hole course.
One member has the honor of making a Holeinone on all four par 3's.
It has taken him 8 years to do it!
How does one go about computing the odds of this TREMENDOUS accomplishment?
Respectfully,
Robert laffal Answered by Victoria West. 





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. 





Fence post holes 
20120719 

From Gerry: Hello, I'm digging 30 8" dia holes, 5 ft deep for fence posts that are 4"x 4" Can you please help me figure out how much stone dust I should order for all 30 holes. Thanks Answered by Penny Nom. 





Two whole numbers 
20110511 

From yolanda: The sum of two whole numbers is 12.If the sum of the squares of those numbers is 74,what are the two numbers? Answered by Penny Nom. 





Odds and evens in an n by n+1 table 
20100121 

From Shankar: The boxes of an n * (n+1) table ( n rows and n+1 columns) are filled with integers.
Prove that one can cross out several columns ( not all of them !) so that after this operation
all the sums of the numbers in each row will be even. Answered by Robert Dawson. 





Friends in a class 
20090914 

From pran: it is known that among any group of three students in a class two of them are friends. the total number of students is 25. prove that there is a student who has at least 12 friends Answered by Claude Tardif. 





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. 





Filling a hole 
20090714 

From BARRY: I HAVE AN AREA THAT i NEED TO FILL WITH DIRT AND AM TRYING TO FIGURE OUT THE CU. YDS NEEDED. tHEY CIRCUMFRANCE OF THE HOLE IS 28' ROUND AND SLOPES FROM 2.5 FEET AT ONE END TO 0 ' AT THE OTHER. OVERALL THE HOLE IS 30' LONG BY 30' WIDE . THE SLOPE RANGES FROM 2.5 ' TO APPROX 4" Answered by Harley Weston. 





Find the lengths, and explain in a 'let statement' 
20071220 

From Cordilla: the length of the sides of a triangle are 3 consecutive whole numbers. The perimeter of the triangle is 102 meters. Find the lengths, and explain in a' let statement'. Answered by Stephen La Rocque and Harley Weston. 





x^2 + x^3 = n^2 
20071114 

From Rapin: x and n are the whole number and less than 100 , x^2 + x^3 = n^2,
please help to solve this equation. Answered by Penny Nom. 





Whole numbers and improper fractions 
20071113 

From Jennifer: I would like to know how you convert whole numbers into improper fractions Answered by Melanie Tyrer. 





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. 





The size of a lot 
20070613 

From Larry: This is driving me crazy, I know i learned this in college but that was so many years ago haha. I am trying to determine how many acres
my property is. Unfortunately everywhere i look is like another language to me when seeing these formulas. My property is square shaped
so starting from one side and just working around the dimensions are: 114 feet x 95.88 feet x 100 feet x 91.91 feet. Answered by Penny Nom. 





Percentage increase and decrease 
20070613 

From Anna: I just want to if the following formula is used for the computation of a PERCENTAGE DECREASE:
Old Value  New Value/ Old Value x 100%
My immediate superior is under the impression that the said formula works ONLY for the computation of a percentage INCREASE. He believes that the formula for a percentage DECREASE:
Old Value  New Value/ NEW Value x 100%
On this score, I want to know the correct formula for the computation of percentage decrease. Thank you so much.
Answered by Penny Nom. 





A 5 digit key 
20070531 

From Michael: I have a 5 digit key pad lock on my truck.
I want to print out all of the combinations to try.
pad one=0 pad two =1 pad three=2 pad four=3 pad five =4.
can you help me find and print all combinations? Answered by Harley Weston. 





Water tank volume 
20070529 

From Cecelia: I HAVE A SEMI CIRCULAR TANK AGAINST A WALL MEASURING 6'10" ACROSS THE WIDEST PART AND 3' FROM THE WALL TO THE FRONT OF THE TANK. THE DEPTH IS 14". PLEASE HELP ME TO CALCULATE THE VOLUME OF WATER IN THE TANK. Answered by Stephen La Rocque. 





How many different ways can she purchase candy? 
20070418 

From fathia: Stephanie can buy lemon candies for 3 cents each and chocolate candies
for 5 cents each. Stephanie has 64 cents to spend. How many different
ways can she purchase candy if she wants to spend all her money? Answered by Stephen La Rocque. 





Drilling holes in a cube 
20061212 

From Liz: What is the volume of the solid remaining if a unit cube has a hole drilled thru one face to the opposite side and the hole that is drilled is a cylinder of unit diameter. Then the cube is rotated and an identical hole is drilled from an untouched face to the opposite side. Then the cube is rotated and an identical hole is drilled between the last two untouched faces. This will result in the cube vertices and the remaining volume of the cube falling into 8 parts. What is the total volume of these 8 parts. How is this volume calculated? Answered by Penny Nom. 





What is the sum of the first 100 whole numbers? 
20060531 

From Jo: what is the sum of the first 100 whole numbers? Answered by Natasha Glydon, Paul Betts and Penny Nom. 





What is the radius of the sphere? 
20060517 

From Jimmy: The surface area and volume of a sphere are both equal to the product of 4digit whole numbers and pi. What is the radius of the sphere? Answered by Stephen La Rocque. 





Improper fractions 
20051021 

From Joe: Is a whole number an improper fraction. For example, is 4 an improper fraction? Is 4 an improper fraction? Is 4 the simplest form for 20/5? Are 4 and 20/5 equivalent fractions? Answered by Penny Nom. 





Whole numbers 
20051010 

From Kirk: Can the sum of two or more whole numbers be less than any of those numbers? Answered by Penny Nom. 





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. 





Divisibility by 2 or 5 or both 
20031030 

From Abdu: How many positive integers less than 1,001 are divisible by either 2 or 5 or both? Answered by Penny Nom. 





Friends and enemies 
20030324 

From Becky:
Consider a room that contains six people. Any two people are either friends of each other, or they are enemies. A. Argue why there are three people, all who are friends, or there are at least three people, all who are enemies
B. Rephrase the situation using graph terminology, using all of these terms correctly: vertex, edge, graph, complement, clique, independent set, and bipartite. Answered by Penny Nom. 





Subsets of the Real Number System 
20020907 

From Christine: In looking for a French equivalent of the word "integer", I found that the word seems not to actually exist in French, and that Canadian schools use the term "natural number" to describe what we have been trained to call "whole numbers," while using the term "whole number" to describe what we have been trained to call "integers." Answered by Claude Tardif. 





20 men dig 40 holes in 60 days 
20020724 

From Lindsey: 20 men dig 40 holes in 60 days. So, 10 men can dig 10 holes in how many days? Answered by Penny Nom. 





Mixed numbers, whole numbers and improper fractions which are less than 2. 
20020303 

From Dawn: Change each mixed number to a whole number and an improper fraction which is less than 2. 3 1/2 = 2 / Answered by Penny Nom. 





The amount of gravel needed to fill a hole 
20011006 

From Rhett: My name is Rhett and my problem is...I am a contractor and I am having problems determining the amount of gravel(in tonnage) needed to fill this hole,the measurements are 60' in length,22' in width,and 14' in height....the problem is that it is not a usual box shaped hole or in this case a rectangle shaped hole,but more of a triangular shaped hole.I refer to the triangular shape as the interior shape of the crater not the exterior,which is shaped like the above dimensions.If you could help it would be greatly appreciated.P.s.This was a retaining wall project,built by myself, in front of a sloped end of a yard,so if you could imagine a 14" high hill with a landslide looking face,then build in your mind a three sided rectangle in front of it using the hill side that slopes as the fourth side of the rectangle,then you may be able to imagine what I mean as a triangular shaped interior of the hole. Answered by Penny Nom. 





Rounding 
20000914 

From MaryAnn: How many whole numbers rounded to the hundreds place, round to 400? Can you also explain why? Answered by Penny Nom. 





Natural numbers 
20000412 

From Sara: What is a natural number??? Answered by Penny Nom. 





Filling a hole 
20000401 

From John McNeill: I have an area 20 feet long and 12 feet wide It starts out at a depth of 4 inches and ends up at 0 inches. How much sand do I need to fill the excavation. Answered by Penny Nom. 





Whole numbers 
19991202 

From Patty: I'm in a 5th grade class, please explaine what whole numbers are..... Answered by Penny Nom. 

