







Nickels, dimes, and quarters 
20180420 

From Patti: A copy machine accepts nickels, dimes, and quarters. After 1 hour, there are 30 coins total, and their value is $5.10. How many nickels, quarters, and dimes are in the machine? (Hint: There are exactly five different solutions.) Answered by Penny Nom. 





Peanuts in 5 bags 
20170917 

From Maria: There are a total of 270 peanuts divided up into five different bags. The first two bags contain 174 peanuts between the two of them. The second and third bags contain 130 peanuts between the two of them. The third and fourth bags contain 86 peanuts between the two of them. The fourth and fifth bags contain 42 peanuts between the two of them. How many peanuts are in each bag? Answered by Penny Nom. 





A puzzle with some integers 
20170330 

From Glen: Use 7,7,5,5 to equal 3 only using each # once and each math function once 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. 





20/2 + 2 * 2^2 + 6 = 8 
20160915 

From Simone: 20/2 + 2 * 2^2 + 6 = 8
insert brackets to make this true Answered by Penny Nom. 





A puzzle embedded in a table top 
20160513 

From Aaron: I want to make a table with a puzzle embedded in it. The table top would be a
36" circle and the puzzle is 20"x27" I'm thinking that it's not going to fit,
but not sure. Any help would be appreciated.
Thanks,
Aaron Answered by Penny Nom. 





A problem with numbers 
20140514 

From Justina: Okay so I don't understand how to equal this equation to 10 using bedmas.
I've been stuck on it for a few days now. Is there different ways you can show me
Using these same numbers?
5 2 4 3 1 = 10
Help! Thanks. Answered by Robert Dawson and Penny Nom. 





Every vertex of a cube is assigned a number +1 or 1 
20130401 

From Shankar: Every vertex of a cube is assigned a number +1 or 1 . Every face has a number that is the product of all the numbers in its corners. Then the 14 numbers are summed up ( all the vertices and faces ). Can the sum be 0? Answered by Chris Fisher. 





A 3 digit number puzzle 
20130311 

From Bonnie: My number has 3 digits. My number is not a multiple of 100. My number is a multiple of 50. My number is a factor of 1000. What is my number? Answered by Penny Nom. 





100 animals 
20130225 

From Jessica: You have exactly $100.00 to spend. You must get 100 animals.
The chicks cost $0.10 each.
The pigs cost $2.00 each.
The sheep cost $5.00 each.
You must get some of each animal.
How many of each animal can you get? Answered by Penny Nom. 





Use 9,10,6,8, and 4 to make 10 
20130125 

From Able: How do you calculate using BEDMAS 9,10,6,8,4 to equal 10 Answered by Penny Nom. 





A balance puzzle 
20130114 

From Emily: I'm stuck on this problem and feel that it can't work! The problem is: there is a door with a balance scale on it. In order to open the door, you have to use the 5 weights to balance the scale. On the left side you have 2 boxes to place the weights and on the right side you have 3. You're 5 weights are as follows: 1lbs, 2lbs, 3lbs, 4lbs, 5lbs. How do you place the weights so that the scale is balanced? Answered by Penny Nom. 





A puzzle with a triangle and 57 
20120425 

From sharon:
Question from sharon, a parent:
We have been battling with this for days and cant find any solution 
Using each of the following numbers once, fill all the spaces in the triangles so that each side of the triangle adds up to 57
numbers are 11,12,13,14,15,16,17,18,19
diagram is 
Any ideas ? this has to be in in just over 24 hrs ......help! Answered by Chris Fisher. 





A number puzzle 
20120407 

From Kenya: my number is less than 25
my number of tiles will make only one rectangle
my number is odd
my number is a factor of 36 Answered by Penny Nom. 





Can the result of the calculation be 2? 
20120209 

From Thomas: You have the digits 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9 in a random order side by side and put randomly between two digits a colon, so that a division comes into existence. Can the result of the calculation be 2? Answered by Robert Dawson and Chris Fisher. 





Today is Emma's Birthday. 
20120125 

From Mike: Today is Emma's Birthday.
Emma's mother is four times as old as Emma is today.
In four years, Emma's mother will be three times as old as Emma.
How old is Emma today? Answered by Penny Nom. 





A problem in logic 
20120119 

From Ghader: The puzzle below I know the answer to; because someone told me! My question is: how could I answer it using logic, maths, etc. what field of inquiry does this kind of problem fall into?
Puzzle: You are in a room with two men: one is a compulsive liar and the other is a compulsive honest. There are two doors: one leading to heaven, the other to hell. The two men know which door leads to where. You want to go to heaven but are allowed only ONE question from one or the other of the two men. What would that question be?
[The question to ask, from either man, is: "if I asked the OTHER man which door leads to heaven, which door would he point?". You would then choose the other door.]
Has this answer got any basis in logic or maths at all? Answered by Robert Dawson. 





15 pigs and 6 pens 
20111116 

From Mike: I have 15 pigs and 6 pens, I have to put them in odd numbers, how do I do it. Answered by Chris Fisher. 





A word puzzle 
20111110 

From kevin: ABCD
ABCD
ABCD
ABCD

EBEA
What does each letter stand for?
I've been at it for days and still have nothing.
Thank you,
Kevin Answered by Robert Dawson. 





Ben's favourite numbers 
20110803 

From Luke: Ben challenges you to guess his favourite numbers by using the following three clues:
Each number is a fourdigit odd number.
Each is a palindrome
The digits of each number add up to 10
None of the numbers are divisible by 5 Answered by Robert Dawson. 





How many cats are needed to catch 60 rats in 1 hour? 
20110419 

From Melody: If 3 cats can catch 3 rats in 3 minutes, how many cats are needed to catch 60 rats in 1 hour? Answered by Penny Nom. 





Ramon has 6 puppies 
20110417 

From Mary: Ramon has 6 puppies. Five of the 6 weigh the same and one puppy is heavier. If Ramon had a balance scale, what is the least number of times he could weigh the puppies to be sure he could determine which puppy was heavier? Answered by Penny Nom. 





2x = 2+2x 
20110115 

From james: 2x=2+2x can you help me find what x epauls? Answered by Penny Nom. 





Draw a figure with 16 triangles using only 6 line segements 
20101216 

From Jill: How can you draw a figure with 16 triangles using only 6 line segements? Answered by Stephen La Rocque. 





A product of 1 000 000 
20101119 

From Sharron: There are many pairs of numbers that when multiplied together give a product of 1 000 000. However, there is one pair, and only one pair, of whole numbers that contain no zero digits and has a product of 1 000 000. What are these two numbers? Answered by Stephen La Rocque. 





What numbers can I be? 
20101113 

From john: my thousands digit is 2 times my ones digit.my hundreds digit is my ones digit plus 2. my tens digit is the difference between my thousands and hundreds digit what numbers can i be? Answered by Penny Nom. 





Bbippities, bops, and boos 
20101105 

From Stacey: six bippities equal three bops,and six bops equal two boos. How many
boos are there in one bippity,one bop, and one boo?? Answered by Stephen La Rocque. 





394+6 divided by 3 to the power of 2 = 3 
20101102 

From Emma: Help me and my family cannot figure this out, it the last question on my paper. I need to know how to use place the brackets to make the following problem true.
394+6 divided by 3 to the power of 2 = 3
we have tried for three days and cannot get it.......help! Answered by Robert Dawson and Claude Tardif. 





Six nines 
20100916 

From Steph: It's sort of one question. We have to use six nines to get the numbers 130. I got all but 22, 23, 24, and 30. Like 15 is 9+9(9+9+9)/9. Answered by Penny Nom. 





Choose any three digits that are less than ten 
20100912 

From cecille: my son have a homework, but i don't understand the question. here's the problem:
choose any three digits that are less than ten.
make all the two digit number you can using those three digits.
add up the two digit numbers you created and divided by the
sum of the original three digits.
record your answer. then do it again with another three digits. write your observation about
the answer. Answered by Claude Tardif. 





There are 12 balls and one balls weight is different than the others 
20100812 

From david: if there was 12 balls and one balls weight is different than the other and use a balance 3 times is there a possible way to find which weigh different Answered by Robert Dawson. 





777777 times 111111 
20100707 

From Chew: What is 777777 times 111111 without using a calculator? Answered by Chris Fisher. 





A table of values 
20100422 

From Donna: Complete the table by determining the value of each letter. Explain what rule is used to relate the numbers in the second column (with the heading of y) with those in the first column (with the heading of x).
x  y
3  5
9  23
4  8
6  A
7  B
C  11
D  2
I can't figure this out, can you help me? Answered by Robert Dawson. 





2+3 =10 and 7+2=63 and ... 
20100301 

From brenda: if 2+3 =10 and 7+2=63 and 6+5 =66 and 8 +4 = 96 then 9+7+ ??????
its driving me crazy !! Answered by Penny Nom, Claude tardif and Melanie Tyrer. 





Dividing between between two charities 
20100222 

From Latoya: a 149,000 estate is to be divided between two charities so that one charity receives 18,000 less than the other. How much will each charity receive? Answered by Penny Nom. 





The game of 24 
20100220 

From haley: hello.... we have these very hard make 24 stumpers. i am stuck on one.... how can you make 24 using the numbers 771318?? thanks! Answered by Claude Tardif. 





7 odd numbers 
20100219 

From mike: Hello there,
Problem: find 7 odd numbers who sum is equal to 30.
Hint*My professor said it's possible to add 7 odd numbers and get 30 for an answer!
and he said we can use Negative and rational numbers but no decimal or fractions.
So is there anyway of solving this? Please get back to ASAP! thanks. Answered by Harley Weston and Tyler Wood. 





A magic square 
20100218 

From Mika: place the integers from 5 to +10 in the magic square so that the total of each row, column, and diagonal is 10. Answered by Tyler Wood. 





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. 





Four fours 
20091129 

From linda: Four Fours order of operations challenge i need problems using 4's only that have an answer of 13, 18, and 19
than you Answered by Penny Nom. 





A place value problem 
20091129 

From Ivy: My tens digit is 4 less than my thousands digit. My ones digit is twice my tens digit. My ten thousands digit is one less than my ones digit. My hundreds digit is the sum of my tens and thousands digit. My thousands digit is 6. Answered by Penny Nom. 





A number puzzle 
20091103 

From Jacqui: Write a number sentence. Use every digit once, 7, 4, 3, 6, 5,10. Insert math symbols +,  , *,/ and end up with the number 3. Use parentheses if necessary.
Jacqui Answered by Claude Tardif and Penny Nom. 





Where is the Father? 
20091030 

From Jeffrey: A mother is 21 years older than her kid and within 6 years the child
will be 5 times younger than the mother. Where is the Father?
Jeffrey Answered by Robert Dawson and Claude Tardif. 





A number between 48 and 59 
20091007 

From nakia: I am a number less 59 but greater than 48. my ones digit is 2 more than my tens digit.What's the number? Answered by Penny Nom. 





In what order are the following digits? 
20090930 

From Jewell: In what order are the following digits?
0,2,3,6,7,1,9,4,5,8 Answered by Penny Nom and Claude Tardif. 





Seven circles 
20090920 

From Bobbi: try to put number 1 to 7 in seven circles (one in the middle, 3 on top, 3 below) so the numbers in each row of three circlesvertical, horizontal, and diagonal  add up to 12. Each number can be used only once. Answered by Stephen La Rocque. 





What is my number? 
20090918 

From Hanna: What is my number?
My number is a perfect square.
The only number in its prime factorization is 2.
My number is a factor of 32.
The sum of its digits is odd. Answered by Penny Nom. 





A fourdigit positive integer 
20090904 

From TRACEY: I AM A FOURDIGIT POSITIVE INTEGER SUCH THAT THE SUM OF MY DIGITS IS 18 AND MY DIGITS REVERSED ARE EXACTLY FOUR TIMES GREATER THAN MYSELF. WHAT NUMBER AM I? Answered by Robert Dawson. 





A number puzzle 
20090828 

From Angela: Taking 1 through 9 and using them only once subtract them to equal 33333 Answered by Chris Fisher. 





The game of 24 
20090826 

From melvi: how can you get the numbner 24 but only useing the numbers 7,5,4,5 Answered by Penny Nom. 





Number of Farm Animals 
20090706 

From paul: In the farm there are 50 heads of chicken and pigs and 100 feet. how many chickens and pigs are there in the farm Answered by Robert J. Dawson. 





You have the numbers 1 through 8, ... 
20090615 

From Maryland: You have the numbers 1 through 8, you can only use each number one time. Two of the numbers are multiplied together, two are subtracted, two more are subtracted and the last two are subtracted. All the answers are the same.
Can't get it, I have racked my brain trying to help. Answered by Claude Tardif. 





Number & Operation Puzzle 
20090612 

From Francine: How can I get the number 26 using 1,2,3,4,&5 and using addition, subtraction, multiplication and division. Each operator and digit must be used exactly once. My son presented me this question and I can't determine if it's even possible. Answered by Janice Cotcher. 





A number puzzle 
20090610 

From Ann:
Hey,
I have a math problem that I can't solve which just happens to be a "mustanswer". The answer to the first problem is 25,452 and the second is 21,232. I know how to add but my teacher said that there is a pattern wherein you just have to look at the set of numbers and you already know the answer without really adding it first. Here are the condition of the problem:
1) the first, second and fourth numbers were provided by me. ( I have no idea how this works)
2) the third and the fifth numbers were given by the teacher. ( She's the one who knows the technique)
# She says that there is a "pattern."
Help me please as soon as you can. Thanks!!! Here it is:
5454 1234
+ 3636 5678 6363
4321
2323
8765
7676 1234
_______ _________
Please answer ASAP. Thank you!!! Answered by Penny Nom. 





A number puzzle 
20090517 

From Gita: Ok, we really need help for a homework problem due on Monday morning
I've been trying for 2 hours and can't figure it outif I can't I'm not sure
how my son can....We've been given a puzzle with the following rules:
The sum of each side must equal 15
We can only use the numbers 1,2,3,4,5,6,7, 8
A number can be used only once
(Hint: Think of all combinations of 3 numbers = 15)
The puzzle looks like this:
_____ _______ ______
_____ ______
_____ _______ ______ Answered by Penny Nom. 





15 pigs in 4 pens 
20090422 

From Melissa: A farmer has 15 pigs. He wants to put them all into 4 pens, have an
odd number of pigs in each pen, and have no pigs left over. Also, he
isn't thinking about having any for dinner, as they are his pets.
How does he do it? Answered by Robert Dawson. 





What is the original number? 
20090416 

From Yueh: A five digit number is written on a blackboard. Ron erases one of the digits and adds a newly constructed number to the original one. The result is 41751. What is the original number? Answered by Claude Tardif. 





A number puzzle 
20090415 

From Julie: Hi, please help me!!! I have a subtraction puzzle...
5 digits minus 4 digits = 33333
Only using numbers 19 once each.
I can get 33323 but then thats it!!! Please how do I work it out?
There must be a simple way??
Thankyou Answered by Claude Tardif. 





Four identical lots 
20090330 

From Marina: I really want to know the answer to this problem for my 6th grade son. I've already sent this question with the drawing but I couldn't send it correctly. I hope this one will pass through.
Q: Divide evenly and identical the figure representing a lot, into four for the 4 siblings. I've sent a figure drawing as attachment. I will describe this in case it will not reach you: its a square divide into 4 triangle and 1 triangle is taken out living a letter M figure and
this letter M figure is the one that will be divided.into 4 even and identical parts.
Marina Answered by Claude Tardif. 





Stacking eggs 
20090312 

From Prashanth: if you stack two eggs eah in row you must get 1 balance
if you stack three eggs eah in row you must get 2 balance
if you stack four eggs eah in row you must get 3 balance
if you stack five eggs eah in row you must get 4 balance
it goes on like 6 , 7 , 8 and finally
if you stack nine eggs eah in row you must get 8 balance
what would be the answer and how to reach it Answered by Robert Dawson. 





Where do X, Y and Z go? 
20090227 

From Aj: A E F H I K L M N T V W
B C D G J O P Q R S U
where do X, Y and Z go? Answered by Robert Dawson. 





A four digit number 
20090212 

From alex: the number of tens plus the number of hundreds equals the number of thousands.
the number of ones is half the number of tens and one more than the number of hundreds the hundreds digit is 2. what is this four digit number Answered by Penny Nom. 





Dividing the digits 1  9 into two groups 
20090209 

From donna: using the numbers 1 to 9 can you arrange these into 2 groups, both of which have the same total, and no you cant turn the 6 upside down Answered by Penny Nom. 





The resulting number is the square of an integer 
20090130 

From Randy: A positive integer n is chosen. Then the product n ( n + 1 )
is computed and two digits are appended to the end of the product. The
resulting number is the square of an integer.
Show that it is always possible to complete the process above or give a
positive integer n for which the process cannot be completed. Answered by Chris Fisher and Claude Tardif. 





How many students were there 
20090125 

From sooos: After a math lecture in university, the students go to the cafeteria. EACH ONE of them buys a cheese sandwich and a cup of tea. They ALL pay $18.49. How many students were they? Answered by Chris Fisher. 





Who am I? 
20090109 

From daphne: im a 2digit number less than 85.the sum of my digits is 9.the number in my ones place is twice my tens digit. who am i? Answered by Robert Dawson and Harley Weston. 





50 coins with a value of $1.00 
20090108 

From Ana: you have 50 coins which have a total value of 1.00. What are the coins and how many of each do you have? Answered by Robert Dawson. 





A 4digit number 
20090105 

From Anya: It is a 4digit number
The tens are double the ones.
The thousands are double the tens.
The sum of the digits is 19.
What number is it? Answered by Penny Nom. 





Two numbers 
20081215 

From HERB: I am thinking of two whole numbers. When I add them , their sum is 123. When I subtract the lesser number from the greater number their difference is 45. What are my numbers? Answered by Penny Nom. 





I am a whole number less than 100 
20081203 

From Cecelia: If I am a whole number less than 100
and the sum of my digits is 4
and half of me is an odd number
What number am I?
Also am I prime or composite? Answered by Penny. 





A 4 digit number 
20081106 

From Chris: numbers 0  9 form a 4 digit number with no repetition.
It would round to 3000 if rounded to the nearest thousand
The digit in the tens place is twice the value of the digit in the thousands place.
It is an odd number.
It contains the largest digit.
It contains one digit less than 2.
The digit in the hundreds place is odd.
Can you find the 2 numbers? Answered by Penny Nom. 





Divide $100.00 between two friends 
20080831 

From anna: divide $100.00 between two friends, so that one has $5.50 more than the other Answered by Penny Nom. 





Four weights 
20080825 

From Darla: A balance had known weights of 1/2 lb, 1/4 lb, 1/8 lb, and 1 oz. Edna's object weighted 2 oz. more than Paul's. Each used 3 known weights to weight his or her object. which know weights did each use? Answered by Penny Nom. 





???? x ? = ???? 
20080720 

From waiyan: ????
x ?
????
using 1 2 3 4 5 6 7 8 9 Answered by Janice Cotcher. 





Girls, cats and kittens 
20080516 

From leria: There are 7 girls in a bus.
Each girl has 7 backpacks
In each backpack, there are 7 big cats
For every big cat, there are 7 little cats.
How many legs are there in the bus? One hint? it's a 6 digit number Answered by Penny Nom. 





seven + eight = twelve 
20080507 

From evelyn: My son's teacher has given the children this question to answer and I do not have an anser.
seven + eight = twelve Answered by Stephen La Rocque. 





1?2?3?4 = 7 
20080425 

From john: 1 2 3 4 = 7
The numbers have to stay in order of 1234 and when added,subtracted,multiplied or divided they have to equal 7. Answered by Stephen La Rocque. 





A square garden of tulips 
20080408 

From Vincent: Each year Brandon plants tulip bulbs in a square flower bed. This year Brandon's flower bed has 29 more bulbs than it had last year. If the flower bed is still square how many tulip bulbs are in it this year? Answered by Penny Nom. 





A number puzzle 
20080322 

From Cassidy: 1. Number has three digits
2. The second digit is an odd number
3. The first and third digits are even numbers
4. The number can be divided by five, six, and seven with a remainder of four.
How do you even start this type of problem? Answered by Victoria West. 





5 9 1 6 10 12 2, where does 3 fit in and why? 
20080322 

From Cassidy: number sequence
5 9 1 6 10 12 2, where does 3 fit in and why? Answered by Claude Tardif. 





Moving grain across the river 
20080312 

From Janice: Wesley needs to move 820 kg of grain across the river in a canoe that can carry no more than 120 kg. Wesley has a mass of 70 kg. What is the fewest number of trips he will have to make? A. 17 trips; B. 18 trips; C. 32 trips; D. 33 trips. Answered by Penny Nom. 





Separate three different sized marbles 
20080307 

From Jana: hello, I love this site, it explains everything so well. I have been asked a question in science, it asks for me to make a devise which separated three different sized marbles. I have thought this through alot but it still never makes sense to me. Everything i seem to think of never works out or has something that will make it not work. I'm really stuck on this one...please help me..! Thankyou so much Jana Answered by Stephen La Rocque. 





A puzzle about hats 
20080303 

From Sylvia: There were 4 people sitting in a row, truing to win $50.00 from a riddle.
The one in front was wearing a red hat.
The second from the front was wearing a blue hat.
The third from the front was wearing a red hat.
The last was wearing a blue hat and is blindfolded.
Each of them were informed that they are all wearing a hat,
the last person is blindfolded and that there are 2 red and 2 blue hats. If they can guess the
colour of their hat, then they win the prize.
There was a long silence, then one of them guessed the color of his hat correctly. Who was it?
and explain why.
(note that they can only see the person in front of them and are not allowed to turn around and
see behind them.) Answered by Penny Nom. 





I am a 4digit number 
20080212 

From Nickie: I am a 4digit number with no repeating digits. I am divisible by 5, my first two digits (left to right) make a number divisible by 3, and my first three digits make a number divisible by 4. Also, my digits have a sum of 19 and I have the digit 7 in the thousands place. Who am I? Answered by Penny Nom. 





Women, cats and kittens 
20080212 

From Paige: There are 7 women on a bus. Each has a backpack. In each backpack there are seven cats. Each cat has seven kittens. How many legs are there total on the bus? Answered by Penny Nom. 





Bales of hay 
20080206 

From mark: 5 bales of hay are weighed 2 at a time in all possible ways. The weights are
110
112
113
114
115
116
117
118
120
121
How much does each bale weigh Answered by Stephen La Rocque and Penny Nom. 





A relationship between numbers 
20080124 

From Robyn: Study these problems: ? 2=4 ? 5=25 ? 9=81
1. Explain what ? means (hint there are two answers).
2. What number is equal to ? 6
3. What number does ? 12 represent? Answered by Stephen La Rocque and Penny Nom. 





A 3 digit number 
20080123 

From Adrian: Consider a 3digit number,abc,where a is not equal to c.Switch it so that it becomes cba.Subtract
the lesser from the greater to obtain rst.Switch this so that it is tsr.Prove that rst+tsr=1089 Answered by Stephen La Rocque. 





Partitioning a clock face 
20071219 

From Kim: Using a clock with a regular circular faced dial, draw two straight lines such that the sum
of the numbers in each of the three areas is equal. Answered by The team at Math Central. 





A 3 digit number 
20071213 

From Kim: Find the number from the following clues:
A) is is a 3 digit even whole # divisible by 5
B} Each digit is different
C) Its hundreds digit is greater than its tens digit
D) It is less that 400, divisible by 3, and has only 1 odd digit. Answered by Penny Nom. 





A math trick 
20071210 

From Megan: I need to write a mathematical explanation of why this works!
Start with a four digit number. (a positive integer, and all digits can NOT be the same. At least one must be different)
Rearrange that four digit number.
Subtract the smaller 4digit number from the larger.
Now circel one digit. (canNOT be zero, because that is already a circle)
Now rewrite that number excluding the circled digit.
Compute the sum of the digits.
Now write down the next multiple of 9 that is larger than the sum.
Subtract the Sum from the multiple. (multiple  sum of digits)
Report Difference = to number circled.
The resulting number should be the number that originally circled. Answered by Penny Nom. 





Two logic problems 
20071207 

From Grace: 1. You are an archaeologist that has just unearthed a longsought triplet
of ancient treasure chests. One chest is plated with silver, one with gold,
and one with bronze. According to legend, one of the three chests is filled with
great treasure, whereas the other two chests house a maneating python that
can rip your head off. Faced with a dilemma, you then notice that
there are inscriptions on the chests:
Silver Chest  Treasure is in this Chest.
Gold Chest  Treasure is not in this Chest.
Bronze Chest  Treasure is not in the Gold Chest
.
You know that at least one of the inscriptions is true,
and at least one of the inscriptions is false. Which chest do you open?
(a) Silver (b) Gold (c) Bronze Answered by Penny Nom. 





math puzzle 
20071129 

From Will: This is a math puzzle called "What's my number"
1. It is a threedigit whole number.
2. It is a square number.
3. It is divisible by 5.
4. it is not an even number.
5.Each of it digit is not different.
6. It is divisible by 9.
7.It is less than 500.
8. Its ones digit is 5.
9.It has only one odd digit.
10. Its tens digit is less than its ones digit. Answered by Leeanne Boehm. 





Rotating letters 
20071126 

From sherry: Ms. Thomas said to her class, when my older was little his nickname was Zed. The nickname my brother gave me was like his but with the first letter turned 90 degrees the second letter changed to the first letter of the alphabet and the third letter turned a half rotation. Does anyone know what my nickname was. My brother gave me the nickname because I slept too much. Could you please explain this to me so I can help my child solve it. Thanks Answered by Leeanne Boehm. 





A 5digit whole number 
20071119 

From sunjoo: a friend tells you to think of a 5digit whole number. then do the following in order : multiply the number by 2. add 200 to the result. divide the result by 2. subtract 100 from the result. what is the greatest number you can get as an answer? Answered by Stephen La Rocque. 





Elimination of mayan prisoners 
20071119 

From Jim: An evil Mayan emperor decides to make an example of 1,000 prisoners. He stands them in a circle with numbers one to a thousand marked on their shirts. He then starts counting: "one in, two, in three out" The third man is immediately executed. This continues round and round and round the circle. While the number in the circle shrinks, every third prisoner is pushed out and executed. And it continues even when there are only two prisoners left alive. What number is on the last prisoner's shirt? Answered by Victoria West. 





EFGH x 4 = HGFE 
20071113 

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





A number puzzle 
20071031 

From matthew: please help.make 200.take 4 numbers from the numbers 19,place the numbers
into a square containing 4 equal squares 1 number to each square.example
13
57 you now have 4 sets of numbers 13 ,57 ,reading across and 15 , 37. reading down
i have to find 2 or more ways of making i have to find the numbers that when added together
using this method make 200.you can only use each number once. Answered by Penny Nom. 





Paying with silver  Part 2 
20071017 

From Shanna: The paying with silver problem. I understand how to do the problem, but could you please explain how you would use base 2 arithmetic to solve it. Answered by Penny Nom. 





4 odd numbers that equal 21 
20071015 

From gary: 4 odd numbers that equal 21 Answered by Penny Nom. 





Show that there is no fivedigit number which 
20071004 

From Greg: show that there is no fivedigit number which uses each of the digits 1,2,3,4,5 such that the numbers formed
by the first digit is divisible by 1,
by the first two digits is divisible by 2
by the first three digits is divisible by 3,
by the first four digits is divisible by 4,
by the first five digits is divisible by 5 Answered by Stephen La Rocque, Claude Tradif and Victoria West. 





How can that be? 
20070926 

From Ken: Al and I have 10 computers on a shelf
10 Team Members came passing by
Each took a computer off the shelf,
leaving 9 computers still on the shelf
How can that be? Answered by Stephen La Rocque. 





Find my number using the following clues: 
20070918 

From T: Find my number using the following clues:
my number will make an array 2 rows wide
my number is greater than 5
my number is less than 30
my number will make a square array
my number is________?
I was not sure where to begin with this word problem  can you help??
Thank you,
T Answered by Penny Nom. 





Cutting a cake 
20070913 

From Bibi: how can one cut 8 pieces from a round cake with 3 straight slices of a knife, without moving any of the pieces? Help me explain this.. Answered by Stephen La Rocque. 





Dividing a pizza 
20070907 

From maryjane: how do you divide a pizza into eight parts using only three cuts? Answered by Chris Fisher and Stephen La Rocque. 





4,18,48,100, __ 
20070807 

From Jeremy: What is the next number in the following sequence?
4,18,48,100, __ Answered by Leeanne Boehm and Stephen La Rocque. 





Alphanumeric addition 
20070701 

From JYOTI: the letters in the alphanumatic addition are all different. find the numbers indicated in codes. all letters are digits from 0 to 9. SEND+MORE=MONEY. Answered by Stephen La Rocque. 





Total of 100 with 1, 2, 3, 4, 5, 6, 7, 8, 9 
20070520 

From Tyler: use all the numbers shown, any of the following four operations +,,x, and division
and parentheses to make a total of 100. You may not change the order of the
numbers, or use them more than once.
1 2 3 4 5 6 7 8 9
Please help asap I can't figure this out.
Thank you
Tyler Answered by Stephen La Rocque. 





How old will they both be when ... 
20070403 

From JOHN: Lisa is 15 years old. Marcus is 49 years old. How old will they both be when Marcus is three times as old as Lisa? Answered by Stephen La Rocque. 





An inheritance problem 
20070323 

From Carl: A father of 3 boys, who owns 17 horses dies. He leaves his first son
1/2 of the horses. The sons hate each other. The father leaves the
second son 1/3 of the horses. They are ready to kill each other. He
leaves his youngest son 1/6 of the horses.
Without cutting the horses into pieces how do they split the horses?
I heard this puzzle when I was 12 years old.
1968
The preacher rides up on his horse and said "If I give you my horse will
you quit fighting ? They agree to stop fighting?" Why? Answered by Penny Nom. 





The game of 24 
20070322 

From Britney: I have a math problem with the game 24. I am not sure how to solve it.
You can use +, , multiplication, division, ( ), square root, and exponents.
Please help me. The numbers are 1, 6, 7 and 8. You have to use all the
numbers and you can only use them once. Answered by Penny Nom. 





What is the remainder when 3^2007 is divided by seven? 
20070218 

From Chris: What is the remainder when 3^2007 is divided by seven?? Answered by Leeanne Boehm. 





How many socks must you take from the drawer? 
20070218 

From Gary: Suppose you have 6 striped socks and 4 red socks in a drawer. How many socks must you take from the drawer to be certain of having a pair of red socks? Answered by Pam Fowler. 





Weightng coins 
20070218 

From Gary: You are considering buying 27 silver coins that look alike, but you have been told that one of the coins is a lightweight counterfeit. Find the least number of weighings on a balance scale that you can use to be certain you have found the counterfeit coin. Answered by Penny Nom. 





*** x ** = **** 
20070216 

From Dani: Use the numbers 19 only once to make the following: A three digit number times a two digit number that gives a four digit number. That is *** x ** = **** (the numbers 19 can only be used once for each star). I came up with the answer 138 x 42 = 5796 but I want to know whether this is the only solution and if not, is there a formula to come up with the answer. Thanks! I appreciate your help! Answered by Chris Fisher and Claude Tardif. 





Centimeters to cubic meters and grams to kilograms 
20070214 

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





More on a man and his wife on an escalator 
20070202 

From Patrick: Hello, I was helping my son with a homework problem and came across a very similar on your site:
http://mathcentral.uregina.ca/QQ/database/QQ.09.01/monty1.html
We are trying to understand the answer shown. There seems to be leap, in the answer that isn't explained or we can't see it. Specifically in the answer it says:
"We know that the woman olny walks 21 steps to reach the top, and thus in the time she walks 7 more steps the escalator also goes up 7 steps. Hence the woman and the escalator are travelling at the same rate."
We understand that she still has 7 steps left, but how is it that you can conclude from that (or other factors) that during those 7 steps the escalator will also travel 7 steps.
Thanks in advance for any help you can offer. Pat Answered by Stephen La Rocque. 





Can you make a square out of a right triangle by using only one straight line? 
20070126 

From Debra: Can you make a square out of a right triangle by using only one straight line? Answered by Stephen La Rocque and Penny Nom. 





Fill in the signs 
20061207 

From Ujwala: 4$4$4$4=20 Fill in the signs in the place of dollor symbol. Answered by Stephen La Rocque. 





27 snakes in four cages 
20061205 

From Sherril: A zookeeper has to put 27 snakes in four cages. His problem is that he must have an odd number of snakes in each cage. How can he accomplish this? You can put any number of snakes in a cage as long as the total number of snakes in each cage is an odd number. Answered by Stephen La Rocque and Penny Nom. 





Pick any prime number greater than 3,square it ,then ... 
20061120 

From Eliseo: I was ask to pick any prime number greater than 3,square it ,then subtract 4, then divide the new result by 12 and record the remainder. He told me the remainder was 9. How could he be sure that the remainder was 9 without knowing which prime I picked? Answered by Stephen La Rocque. 





How can half of 12 be 7? 
20061116 

From Liz: How can half of 12 be 7? Answered by Steve La Rocque, Chris Fisher and Penny Nom. 





Where did the extra unit come from? 
20061103 

From Daniel: There are two triangles each with a base of 8, a height of 3 and an area of 12 units squared and two trapezoids, each with a one parallel side that is 3 and one that is 5 and a height of making it have an area of 20 units squared. When arranged in a 8x8 square then the total area is 64 units squared, but when arranged in a 5x13 rectangle the total area is 65 units squared, where did the extra unit come from? Answered by Haley Ess. 





Replace the blanks with + or  to make the statement correct 
20061013 

From Molly: Hi my name is molly, and I have a question I can't answer and need your help. I am a student. This is the qustion:
Try to replace the blanks below with + or  to make the statement correct
1_2_3_4_5_6_7_8_9 = 1 Answered by Claude Tardif. 





A 5x2 rectangle 
20061003 

From Stanley: Cut a 5x2 rectangle into 4 pieces, and then put them back into as a square. Answered by Claude Tardif and Penny Nom. 





10 friends run into each other at a bar 
20060819 

From Ken: 10 friends run into each other at a bar. We will name them A,B,C,D,E,F,G,H,I AND J.
They all leave at the same time heading for seperate bars. However, A runs into B, C runs into D, E runs into F, G runs into H and I runs into J. These five groups leave again and the same thing keeps happening, but each time running in to someone they have not run into before. How many bars will it take, with each person meeting the others only once, until all of them have met each other again? Answered by Chris Fisher. 





Two water jugs 
20060705 

From Kisha: suppose that you have two water jugs, one which holds three gallons and one which holds five gallons. in additions, you have a water faucet at your disposal. your job is to find a method that produces exactly one gallon of water, another method that produces exactly two gallons of water, another method that produces exactly three etc up to exactly eight gallons of water. you may fill jugs from the faucet or from one another. you may not rough estimates??? Answered by Penny Nom. 





A number puzzle 
20060630 

From Atitya: The diagram given below consist of seven line segments and six circles,place the numbers 1 to 13 on either a line or a circle in such a way that the numbers on each segment is the difference of the two at its end points. Answered by Stephen La Rocque and Penny Nom. 





As close to 841 as possible 
20060621 

From Alan: using these numbers by either add subtract division multiply come up with the answer as close to 841
100 25 10 7 6 3 Answered by Paul Betts. 





How much did I have in my wallet when I lost it? 
20060615 

From Marangeo: I recently lost my wallet and when it came to completing the police report I couldn't remember how much money I had in there. I do remember thinking that the first time I bought something that it cost me 10 per cent of what I had. Then I noticed that the second purchase had also cost me exactly 10 per cents of what I had left. My receipts totalled $19. How much did I have in my wallet when I lost it? Answered by Stephen La Rocque. 





What is the probability that the policeman will shadow the correct person? 
20060614 

From Kolby: Through an informer from the underworld, the police know the meeting place of a gang. The identity of the different gang members, however, is unknown. it is the duty of a policeman to shadow the leader of the gang. The policeman knows that the leader is the tallest of the five persons, all of whom have different heights. after the meeting, the gangsters, as a safety measure, leave the building separately at intervals of 5 minutes. As the policeman cannot see who is the tallest, he decides to let the first two gangsters go and shadow the one after that who is taller than all those who left before.Through an informer from the underworld, the police know the meeting place of a gang. The identity of the different gang members, however, is unknown. it is the duty of a policeman to shadow the leader of the gang. The policeman knows that the leader is the tallest of the five persons, all of whom have different heights. after the meeting, the gangsters, as a safety measure, leave the building separately at intervals of 5 minutes. As the policeman cannot see who is the tallest, he decides to let the first two gangsters go and shadow the one after that who is taller than all those who left before. What is the probability that the policeman will shadow the correct person? Answered by Steve La Rocque and Claude Tardif. 





How many people are in the race? 
20060407 

From Marty: You're in a race with 1/5 of the racers ahead of you and 5/6 of them behind you. How many people are in the race? Answered by Penny Nom. 





A number puzzle 
20060322 

From A teacher: Students brought this website to my attention and asked why this puzzle worked... I'm not sure. The url is: http://digicc.com/fido/ and it tells you to choose a 3 or 4 digit random number with different digits. Write it down, rearrange, subtract the smaller from the larger. then circle a nonzero digit, type the remaining digits into the space provided and they will tell you the number you circled. Can you provide the reason that this works. Answered by Claude Tardif and Penny Nom. 





8,_,4,9,1,_,10,3,_,0 
20060308 

From Rachel: I cant figure out this sequence if someone could help me
8,_,4,9,1,_,10,3,_,0 Answered by Claude Tardif. 





2,4,9,6,5,6,____,____,____,... 
20060306 

From Mike: I am having problems figuring out the following sequence:
2,4,9,6,5,6,____,____,____,...
We were able to guess that the pattern simply started to reverse itself,
but I was wondering if there were other possibilities.
Answered by Claude Tardif. 





The nth term 
20060305 

From Umar: my question is what is the nth term for a house of cards 4 stories high if you use the following numbers:
2 7 15 26 Answered by Penny Nom. 





Separate 35 into two parts such that 4 times the larger is 4 less than five times the smaller 
20060301 

From Barbara: Separate 35 into two parts such that 4 times the larger is 4 less than five times the smaller Answered by Stephen La Rocque. 





Luke and Slim have only one horse. 
20060226 

From Emily: Luke and Slim have only one horse. Luke rides for the agreed on distance and then ties up the horse for Slim, who has been walking. Meanwhile, Luke walks on ahead. They alternate walking and riding. If they walk 4 miles per hour, and ride 12 miles per hour, what part of the time is the horse resting? Answered by Penny Nom. 





The nth term of a sequence 
20060221 

From Mike: I'm having trouble finding the nth term in an equation, can you help me? Answered by Stephen La Rocque. 





Whose photo is he looking at? 
20060219 

From Adeyeri: Looking at a picture a man says, that the father of the person (in photo) is the son of my father. whose photo is he looking at? Answered by Penny Nom. 





Zhi Wei was born on christmas day in 1983. 
20060214 

From Clement: Zhi Wei was born on christmas day in 1983. His father shares the same birthday, but he was born in 1951. In which year will Zhi Wei's age be exactly 1/3 of his father's age? Answered by Stephen La Rocque. 





Grade 3 Math Puzzle 
20060208 

From Jayne: The question is to use the numbers 1 through 9. They are to be placed on lines, and each group is to add up to 11. The trick is that the first 2 numbers used add to 11, then lines 2, 3 and 4; then lines 4,5 & 6; then lines 6,7 & 8; and then lines 8 and nine (it is really hard to describe. In the book, is shows circles making each group). The lines are all horizontal, and lined up to each other like:_ _ _ _ _ _ _ _ _ Answered by Claude Tardif. 





More on the game of 24 
20060202 

From Cathy: 10,16,9,4 this numbers have to equal up to 24. we can't figure it out. Answered by Claude Tardif. 





Make 2 rows of 4 circles with only 6 circles 
20060131 

From Sarah: Moving as many circles as you need, make 2 rows of 4 circles only having 6 circles? Answered by Chris Fisher. 





Who is lying? 
20060114 

From Diane: A business man was working in his home office when he realized he had left a fivedollar bill in the book he had been reading. He called his butler to bring him the book from the library. When he got the book, the bill was no longer there. He then questioned the maid and the butler. The maid remembered seeing the bill between pages 99 and 100 in a book to the left of a business book. The butler did not recall seeing the bill, but was sure the book was to the right of the business book, because to the left of it there was a statistics book. Who is lying?
Answered by Penny Nom. 





Twelve golf balls 
20051228 

From Todd: You have 12 golf balls and 11 of them are the exact same weight, but one of them is either a little heavier or a little lighter. You only have three attempts to weigh the balls. How can you determine which ball weighs more/less than the rest? Answered by Penny Nom. 





Two dogs and a flea 
20051223 

From Michelle: Two dogs, each traveling at 10 ft/sec, run toward each other from 500 feet apart. As they run, a flea flies from the nose of one dog to the nose of the other at 25 ft/sec. The flea flies between the dogs in this manner until it is crush when the dogs collide. How far did the flea fly? Answered by Penny Nom. 





Complete the array 
20051211 

From Ginger:
Make the sum of these number add up to six.
Going across, down, corner to corner. Using the number 4, 2, 0 only.
Answered by Penny Nom. 





Fill in the blanks 
20051205 

From Bonnie: Distribute the numbers 1 through 9 on the lines below so that two equations are true.
_ _ x _ = _ _
_ x _ = _ _
Use each digit only once Answered by Penny Nom. 





Add one 1 at the beginning and at the end of a number 
20051113 

From Samuel: If we add one 1 at the beginning and at the end of a number, this number is increased by 14789.
What is the sum of the digits of the number? Answered by Penny Nom. 





What number am I? 
20051027 

From Samantha: First 8 is added to me, then I am multiplied by 6. Then 40 is subtracted from me. Finally, I am divided by 10. The result is 11. What number am I? Answered by Penny Nom. 





What is the number? 
20051010 

From Jess: One eighth of the square root of 7 less than a number is 2. What is the number? Answered by Penny Nom. 





Two groups that have equal sums 
20050930 

From Anita: using the numbers 1, 2, 3, 4, 5, 6, 7,and 8. how do we divide them into two groups so that they have equal sums? Answered by Penny. 





A multiplechoice and truefalse exam 
20050928 

From Kiat:
Harry, Neville, Ron, Hermione and Malfoy each answered five questions on O.W.L. exam consisting of two multiplechoice questions (A, B or C) and three TrueFalse questions. They answered the questions as follows:
Student 
Q1 
Q2 
Q3 
Q4 
Q5 
Harry 
A 
A 
T 
T 
T 
Neville 
B 
B 
T 
F 
T 
Ron 
A 
B 
T 
T 
F 
Hermione 
B 
C 
T 
T 
F 
Malfoy 
C 
A 
F 
T 
T 
If no two students got the same number of correct answers, who got the most correct answers? And what is the correct answer for each question?
Answered by Denis Hanson. 





Use the numbers and symbols only once to come up with the answer 
20050919 

From Kaitlyn:
Question: I have math problem that no one in my class was able to solve but the teacher said it does have an answer. We need to use the numbers and symbols only once to come up with the answer:
36 18 12 6 +  ( )
______________________________ = 41
Answered by Claude Tardif. 





The trinity concept says three is one. 
20050917 

From Kevin:
The trinity concept says three is one. Mathematically, I will attempt to proof this.
Let G be God and T trinity. We start with
G = T
2G = 2T Double both sides
G + 2G = G + 2T Add G on both sides
3G = G + 2T Simplify
3G  3T = G + 2T  3T Subtract 3T on both sides
3(G  T) = G  T Factor 3 on the left, simplify on the right
3 = 1 Divide (G  T) on both sides.
But how can three equals one? Can it?
Answered by Leeanne Boehm. 





What is my number? 
20050916 

From Bob: I have 6 digits.
100,000th digit is one less than my ones digit, eight greater than my 1,000's digit, twice my tens digit and four times my 100s digit. My 10,000s digit is 0
What is my number? Answered by Penny Nom. 





Who is taller: John or Mary? 
20050914 

From Ulises: All the students in a school are arranged in a rectangular array. After that, the tallest student in each row was chosen, and then among these John Smith happened to be the shortest.Then, in each column, the shortest student was chosen, and Mary Brown was the tallest of these. Who is taller: John or Mary? Answered by Penny Nom and Claude Tardif. 





Cows, chickens and pigs 
20050910 

From Markequetta: I was asked a question by a friend who refuses to give the right answer to a question that I answered wrong. So if you can help me that would be great! The level of my question is secondary I believe.
Question:
Cows cost: $10
Chickens cost: $0.50
Pigs cost: $3
You have to buy 100 animals and spend $100, so how many cows, chickens, and pigs do you have on your farm? Answered by Claude Tardif. 





1_2_3_4_5_6_7_8_9 = 1: Fill in the blanks 
20050826 

From James: Try to replace the blanks below with + or  to make the statement correct
1_2_3_4_5_6_7_8_9 = 1 Answered by Penny Nom. 





A set of numbers whose sum is 1 
20050721 

From Santos: Does there exist a set of numbers whose sum is 1, and the sum of whose squares is less than 0,01? Answered by Paul Betts. 





5+5+5=550 
20050530 

From Bill:
5+5+5=550
This is a math equation that is not true.
How can it be made to be true by using only one line? Answered by Leeanne Boehm. 





A flaw in a problem 
20050415 

From Bryce:
Question:
(x^{2}x^{2}) = (x^{2}x^{2})
x(xx) = (x+x)(xx) [divide both sides by (xx)]
x = x + x
x = 2x [divide both sides by x]
2 = x/x = 1
Where is the flaw in this problem?
Answered by Paul Betts. 





Half of five 
20041226 

From Pauline: Why is four half of Five? Hint: It's the middle half? Answered by Penny Nom. 





Slicing cubes 
20041123 

From Anthony: You are working with a power saw and wish to cut a wooden cube 3inches on aside into 27 1inch cubes. You can do this by making six cuts through the cube keeping the pieces together in the cube shape. Can you reduce the number of necessary cuts by rearranging the pieces after each cut? Answered by Chris Fisher. 





Planting trees 
20041115 

From Heather: Design a plan of how it would be possible to plant 10 trees in 5 rows, and have 4 trees in each row. Answered by Penny Nom. 





Driving me crazy 
20040918 

From Jerry: This is driving me crazy!!! Someone told me of a number that can be divided EQUALLY by each of the following individual numbers: 1,2,3,4,5,6,7,8,9. what is that number? Answered by Penny. 





A challenge 
20040917 

From Lasse: xy
xx
xyx
xxx
xyxx
"x" and "y" each represents a number.
Find out the system to make the next line Answered by Penny Nom. 





How to dry matches 
20040906 

From Liz: The neighbors of a young man who needed seclusion for a few days offered him the keys to their cabin in Maine. Arriving there on a damp and cold autumn evening he saw that while the cabin had normal running water and electric lights, for heat it had only a potbellied stove. Fortunately, there was plenty of wood, kindling, newspaper, and matches. Being an experienced hand at making a fire, he opened the damper, put into the stove crumpled newspaper, and properly stacked the kindling and logs. The matches, however, wouldn't light. They were too damp from the humidty. The nearest town was 30 miles away, and, anyway, it was late. What next? Answered by Claude Tardif. 





Nine minutes 
20040902 

From A student: You have two hour glassesone measures 7 minutes and one measures 4 minutes.How can you time 9 minutes? Answered by Penny Nom. 





Two water jugs 
20040816 

From A student: You go to a source of water with two jugs and only two jugs. One jug has a capacity of exactly three pints and the other five pints. Both jugs are opaque (you can`t see inside them) and irregularly shaped. You have no other water containers. You do not have a scale. How can you use the two jugs and only the two jugs to measure exactly four pints of water? Answered by Penny Nom. 





Two puzzles 
20040713 

From Fred: A young man's car developed a flat tire while he was driving along a deserted street. He pulled over to the curb and did all the usual things; removed the hub cap; unscrewed the lugs and rested them carefully in the hub cap, jacked up the car. As he was putting the spare tire onto the axle he accidentally kicked the hub cap. The lugs rolled out, and all five of them rolled down a nearby grate. Peering through the bars of the grate the man thought he could see the lugs about 6 feet below in a shallow water puddle. He had a problem, how do you think he solved it?
It is noon, your lunch hour, but you can not go out because there is a terrific hailstorm. Turning on your radio you hear the weathercaster predict that the hail will change to rain and that it will pour all day today. How can you determine the sun will be shining in 36 hours? Justify your answer. Answered by Penny Nom. 





Pick a number greater than 1 
20040625 

From A student: I understand that when you pick a number greater than 1 and less than 10; multiply it by 7 and add 23, then add the digits of that number until you get a one digit number. Then multiply that number by 9, add the digits of that number until you get a one digit number, subtract 3 from that number and divide the difference by 3; that this process will always give you the result of 2. Does this have a name or theory for it as to why the answer will always be 2? Answered by Penny Nom. 





Integers 
20040610 

From A parent: I have an odd 3 digit product. My factors are a 1digit number and either or 2 or 3digit number. My factors are odd, but neither is 1. Find my factors and my product.
There is one answer. What is it? Answered by Penny Nom. 





A clock chimes 7 times in 7seconds 
20040502 

From Anna: A clock chimes 7 times in 7seconds. how long does it take the clock to chime 10 times? Answered by Penny Nom. 





Marching legion 
20040424 

From Art: A column of soldiers is 100 meters long. Their sargeant at the rear of the column gives the order to march. The sargeant marches alongside the column to its head and then back to the rear, at which point he gives the order to halt. In all, the column of soldiers has marched 100 meters. How far has the sargeant marched? I say 187.5 meters, but those who teach or who have taught mathematics tell me no. Some say much more and some different. What do you say? Answered by Penny Nom. 





The "22" puzzle and the "1089" puzzle 
20040422 

From Marcelle:
1. Choose 3 digits from 19
2. Make all the 2 digit numbers you can from these (6)
3. Add the 3 original digits and divide them into the sum from step 2.
The answer is always '22'. I just can't understand why. Can you please help.
Another one related to this is it:
1. Choose a three digit number ensuring the first and third digit are differnt by at least two.
2. Make the reverse three digit number and subtract the smaller one from the larger of these.
3. Take this answer and reverse it and add these two 3 digit numbers .
eg:
643  346 = 297
297 + 792 = 1089
it doesn't matter what numbers are used, the results are alwasy the same. eg 22 or 1089
Answered by Paul Betts. 





Numbers around a circle 
20040328 

From Rebecca: my maths question is use the numbers 1,2,3,4,5,6 and 7 place each number in a circle so each line adds up to 12. There are seven circles, six on the outside and one in the middle. Each number lines up with the middle number and the outside numbers line up with the one directly across from it as if a line was going through the middle number circle. Answered by Penny Nom. 





Three jugs 
20040226 

From Shelly: You have three jugs: A 6 Liter, 4 Liter and a 3 Liter. Your goal is to get exactly 5 Liters of liquid in the 6 Liter jug. Your supply of liquid is unlimited and there are NO markings on the containers. You cannot do halves. Answered by Claude Tardif. 





Will be shinning in 36 hours? 
20040208 

From Kim: It is noon, you lunch hour, but you cannot go out because there is a terrific hailstorm. Turning on you radio you hear that weathercaster predicts that the hail will change to rain and that it will pour all day today. How can you determine whether the sun will be shinning in 36 hours? Justify your answer. Answered by Penny Nom. 





A riddle 
20031119 

From Sarah: Ok, our teacher gave us this riddle, and I cannot for the life of me figure it out. He said that there are three problems with the following proof: Answered by Penny Nom. 





Three problems 
20031116 

From Megan: My name is Megan and I am a junior in high school. Our teacher gave us a few xtra credit questions and I need some help. Answered by Penny Nom. 





10,000 
20031008 

From Nathan: what two numbers make the product of 10,000. Neither number can end in a zero Answered by Penny Nom. 





I can Guess your birthday 
20030829 

From Michelle: Hi I am trying to explain to my children how this problem works. It was sent to me on the internet and I can not figure it out. They keep asking me how it works and I can not tell them. The problem is: "I can Guess your birthday:: Answered by Penny Nom. 





A worm on a hill 
20030821 

From Lisa and Samantha: A WORM IS AT THE BOTTOM OF A 10 FOOT HILL. HE CRAWLS UP THE HILL 4 1/2 FEET A DAY. AT NIGHT WHEN HE REST HE SLIDES DOWN 2 1/2. HOW LONG DOES IT TAKE THE WORM TO CRAWL UP THE HILL. Answered by Penny Nom. 





A problem with lugs 
20030711 

From Lori: A young man's car developed a flat tire as he was driving along a deserted street. He pulled over to the curb and did all the usual things: removed the hub cap, unscrewed the lugs and rested them carefully in the hub cap, jacked up the car. As he was putting the spare tire onto the axle he accidentally kicked the hub cap. The lugs rolled out, and all five of them fell down a nearby grate. Peering through the bars of the grate the man thought that he could see the lugs about 6 feet below in a shallow water puddle. He had a problem. How do you think he solved it? Answered by Penny Nom. 





The sum of two numbers is 5 and their difference is 
20030616 

From Akhil: The sum of two numbers is 5 and their difference is 11. What is the product of the two numbers? Answered by Penny Nom. 





The square of my age was the same as the year 
20030414 

From Pat: Augustus de Morgan wrote in 1864, "At some point in my life, the square of my age was the same as the year." When was he born? Answered by Penny Nom. 





Jo's books 
20030407 

From Miguel: Jo announces, "I have more than 999 books." Jean says: "No Jo! You have fewer than 1,000 books." Mary says: "Jo has at least 1 book." Only one of these statements is true. How many books does Jo own? Answered by Penny Nom. 





X times Y equals ten million 
20030226 

From Baneen: Would you be able to tell me which two numbers would compute ten million without any number having zeros in it? Answered by Penny Nom. 





Dorothy and the wizard 
20030124 

From Ken:
dorothy was going to see the wizard of oz...she stopped at the bakery and bought a box of cookies. she met the scarecrow and gave him half the cookies. she ate half of the remaining cookies and threw one half cookie away. she met the tin man and gave him half the cookies. she ate half the remaining cookies and threw one half cookie away. she met the lion. she gave him half of her cookies. she ate half the remaining cookies and threw the LAST half cookie away. how many cookies did dorothy leave the bakery with? Answered by Penny Nom. 





The cousin of Sally's sister's boyfriend 
20030123 

From Michael: Sally went to a farm to buy eggs. Returning home, she gave half of them to her sister who, in turn, gave a third of those she had gotten to her boyfriend. The latter, after eating one third of the eggs that he had gotten, gave the rest to his cousin. Given that each egg weighs 70 grams, that Sally cannot carry more than 2.5kg, and that the eggs were raw, calculate how many eggs the cousin of Sally's sister's boyfriend received. Answered by Penny Nom. 





A penny, a nickel, a dime, a quarter, and a loonie 
20030121 

From Blaine: I have 5 coins: a penny, a nickel, a dime, a quarter, and a loonie. How many different amounts of money could I pay using any combination of these coins? Answered by Penny Nom. 





Jo's books 
20030121 

From debra: Jo announces: I have no more than 999 books. Jean says: No Jo, You have fewer than 1,000 books. Mary says: Jo has at least 1 book.
Only one of these statements is true, How many books does Jo own?
I do not know HOW to approach this problem and solve it. Answered by Penny Nom. 





NO REDHATTED DWARVES ALLOWED 
20030114 

From Dulce:
There are 1000 dwarves in Dwarfland. Now as you know, dwarves are born with either red or white hats on. The dwarves in Dwarfland love to party. Every night, they all flock to the same club to dance the night away. One day, a sign is posted at the club: "NO REDHATTED DWARVES ALLOWED". A certain number of days pass, after which all of the whitehatted dwarves are in attendance,and none of the reds. How did the red hats know not to come? Assumptions:  The number of red and whitehatted dwarves need not be equal. There are at least 1 of each color.
 There are no reflections or mirrors in Dwarfland (i.e. the dwarves can't see the color of their own hat), and no dwarf can reveal through direct or indirect means the color of another dwarf's hat.
 There is NO COMMUNICATION among dwarves
 No whitehatted dwarf ever misses a night of partying
Answered by Claude Tardif. 





A rope trick 
20021205 

From Jerry: My name is Jerry and I am a math teacher at the secondary school level in the greater Toronto area. I posed the following problem to my enriched grade 10 math class that I found in the book called "Mathematics and the Imagination" by William Kastner. According to the author, it is posible for two people linked to each other with two ropes around their hands, to separate themselves without letting go of the rope. The students had lots of fun trying to accomplish this problem using skipping ropes from the Phys Ed department, but with no success. Answered by Penny Nom. 





Making 7 
20021126 

From Bill: At one time I had the answer to this math equation but I have lost it and can't seem to regain it. I may be going at it wrong but as I recall there were the numbers 1 through 4, and the std operators, +, , /, *, and parentheses. The object was to make the four numbers with the operators equal to 7. Each number and operator may be used only once. My 9 year old loves these quizzes but I can't give it to her if I can't provide the correct answer. Answered by Claude Tardif. 





4 x abcd = dcba 
20021120 

From A student: Say you have a four digit number (e.g. abcd) and you multiply the number by 4. The answer you get will be the reverse order of the number you started with (dcba). What is the number? The four digits (a,b,c,d) cannot be the same number or cannot be repeated. Answered by Penny Nom and Claude Tardif. 





Three bags of marbles 
20021108 

From A student: I have 3 bags of marbles 1 bag is labeled blue; 2nd bag is labeled red; 3rd bag is labeled blue & red all the bags are mismarked your job is to take one marble from 1 bag look at it and correctly label all the bags Answered by Penny Nom. 





What are the digits? 
20021024 

From Ebenezer: There are three digits. The middle digit is zero and the sum of the first and last digits are is 13. When the number is reversed it is increased by 297. What are the digits? Answered by Penny Nom. 





Use each digit 19 only one time each,... 
20021019 

From Megan: Use each digit 19 only one time each, divide the numbers into 3 groups, make one 2 digit number, one 3 digit number, and one 4 digit number. There are 6 combinations of these numbers in which you can multiply the 2 digit and 3 digit number together to get the 4 digit number (using each digit 19 one time each). What are they!!!!!!!!!???????????? Answered by Claude Tardif. 





8 squares from 12 sticks 
20021008 

From A student: If you have 12 sticks the same size, how do you make them into 8 squares? Answered by Claude Tardif. 





Number play 
20020924 

From Julie: Organize these numbers and the operations so that each equation is correct. Use each coice only once per equation.
36 18 12 6  + ( ) /
_________________________ = 22
_________________________ = 41 Answered by Claude Tardif. 





A fish weighs 10 pounds more than half its weight. 
20020910 

From Rebecca: A fish weighs 10 pounds more than half its weight. How much does it weigh? Answered by Penny Nom. 





The community garden 
20020908 

From Michele: Bryce, Duanne, Juliana and Sonya share a 40ft by 48 ft rectangular portion of the community garden in the neighborhood. With this space each has their own rectangular garden plot. Bryce is the only one with a square plot. its are is 1/2 the area of Duanne's The area of Bryce's plot is 2/3 the area of Julianna's plot. Their plots have one side in common. Sonya's garden has an area twice that of Julianna's garden. What are the dimensions of each person's garden plot? Answered by Leeanne Boehm. 





Place six numbers around a triangle 
20020719 

From Monika: I need to place six numbers around a triangle, as such that one number is on each corner, and one number on each side making three numbers in one line, adding up to two hundred exactly. The number I have to use are, 40, 50, 60, 70, 80, 90. I have to use each one once, there for, each number cannot be repeated. Answered by Claude Tardif and Chris Fisher. 





Can you make up a word that adds up to 1000000? 
20020719 

From Adrie: My question is elementary and I am a student Please help me with the following conundrum, as it is driving me crazy.
'When the letters in the alphabet are given values from 1 to 26 for A to Z, can you make up a word that adds up to 1000000 ( one million )used as a multiplication?'
Like 'cat' would be 3*1*20 = 60 Answered by Claude Tardif. 





100 from four 9's 
20020327 

From A student: My teacher gave us a math problem to try and figure out and I am stumped. The problem was this.... by only using four nines, how can you get an answer of 100? You can add, subtract, multiply or divide...anything you need to do ,but you can only use four nines. Answered by Leeanne Boehm. 





A sequence 
20020307 

From Caroline: hi, here is the problem,
1 11 21 1211 111221 _ _ 2_ _ _ we can't get the sequence of the last line ,with the 3rd number being 2,thanks Answered by Walter Whiteley. 





What number am I? 
20020303 

From Samantha: I am an even number that has more ones than tens. My thousands digit is the quotient of 9 divided by 3 and my tens digit is the sum of 3 and 3. I have no hundreds. What number am I?......Please answer this for me...The answer I come up with is 3,060...Is this right?.. Answered by Penny Nom. 





A hat of a different color 
20020224 

From Kirstin: A teacher made a deal with 3 of his students. He said that if you can guess what color hat you have on your head without looking, I will pass you. There were 2 red hats and 3 blue hats. The deal worked like this: The three students would close there eyes, and the teacher would put a hat on each of their heads and then hide the other 2. Then one at a time, the students would open their eyes and try to figure out what color hat was on their head. The student could guess or pass. This is what happened when they put their deal to the test: A boy named Arturo was first and opened his eyes but wasn't sure so he passed so he didn't get it wrong. Belicia was next and she passed too because she wasn't sure. Also she thought about the fact that Arturo didn't know. Carletta was last and without even opening her eyes, she knew for sure what color hat she was wearing and her answer was right. So i have to figure out what color hat she's wearing for sure. Answered by Claude Tardif. 





I am a fraction 
20020201 

From Anthony: I am a fraction that is greater than 1 but less than 2. The sum of my numerator and denominator is 11. My denominator subtracted from my numerator is 1. What fraction am I? Answered by Paul Betts. 





Making 24 
20020117 

From Renee: My 4th grade daughter and I need to find a simple math sentence using 5, 5, 3, & 7 to equal 24. You can add, subtract, divide or multiple. Answered by Penny Nom. 





A sale on eggs 
20020117 

From A student: A store had a sale on eggs, selling 13 eggs for the usual price of a dozen eggs. As a result, the price of the eggs was reduced by 4 cents a dozen. What is the original price for a dozen eggs? Answered by Penny Nom. 





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. 





How do you get to 100 by using 6 nines? 
20011117 

From A student: How do you get to 100 by using 6 nines? Answered by Claude Tardif. 





Subtracting 5 from 25 
20011005 

From Melissa: How many times can you subtract the number 5 from 25? Answered by Leeanne Boehm. 





27 
20010910 

From Kacy: In class we were given this problem. We have the numbers 30, 29, 19,11,26. these numbers = 27 in some way but how? the numbers can be applied any way using +  / X ( ) but can only be used 1 time each. can you please help me. Answered by Claude Tardif. 





Three fractions 
20010910 

From Kathleen: a/bc + d/ef + g/hi = 1 Each of three fractions has a onedigit numerator and a two digit denominator. The three fractions together add up to one. Place the nine digits 19 into the fractions to make the equation correct. Answered by Claude Tardif. 





Two snakes 
20010831 

From A student: Two snakes(pythons,actually)of same size and shape start swallowing each other by the tail with the same speed. What will happen ultimately? Answered by Claude Tardif. 





Water jars 
20010827 

From Pe3te: Stacie and Kacie each have a jar. Stacies jar holds 5 quarts of water and Kacies jar holds 3 quarts. The girls dad ask them to go get him some water from the pump and to get him 1 gallon of water (NO MORE NO LESS) The jars were not marked in any way. In ten minutes the girls where back with 1 gallon. How did they get exactly 1 gallon ? 1) there are two ways to do it I only no one. 1st answer is..... Answered by Penny Nom. 





How far does the fly fly? 
20010807 

From Harold:
6 MPH 4 MPH
Rachel  Eli
10 Miles apart
The fly is on Rachels handlebars. The fly is scared so it flys back and forth at 20 MP H. How far has the fly flown when Rachel and Eli meet? f Answered by Penny Nom. 





5+5+5=550 
20010611 

From Tom: I am in algebra and my teacher gave us an equation that was not true. she told us that we could only use one line segment(it can't bend turn has to be straight) to make the equation true. here is the equation: 5+5+5=550. i have not figured it out but have tried many things and believe it is not mathmatical but cross a # or sign out.also i forgot you can't put a slash mark through the equals sign. Answered by Penny Nom. 





Where is the other $1? 
20010605 

From Samantha: 3 people go to a motel. The room is $30. They split it $10 each. While in the room the Mgr. tells the clerk the room was only $25, so he gives her $5 to take back to the 3 people. On the way she cant decide how to split the $5 between the three people so she puts $2 in her pocket and gives them $1 each.....Therefore, the room now only cost the three people $9 each, which is $27 plus the $2 the clerk pocketed,making a total of $29.....Where is the other $1? Answered by Leeanne Boehm. 





Two jugs 
20010604 

From Heather: One goes to a source of water with two jugs and only two jugs. One jug had a capacity of exactly three pints and the other five pints. Both jugs are opaque (you canít see inside them) and irregularly shaped. How can you use the two jugs and only the two jugs to measure exactly four pints of water? Answered by Harley Weston. 





24 from 2, 2, 14, and 21 
20010508 

From Kimberly: using the numbers 2, 2, 14, and 21. how can you get 24 using +  X or division Answered by Claude Tardif. 





The number of occurrences of 0 is __, of 1 is __, of... 
20010417 

From Martyanne: "In this sentence the number of occurrences of 0 is __, of 1 is __, of 2 is __, of 3 is __, of 4 is __, of 5 is __, of 6 is __, if 7 is __, of 8 is __, of 9 is __."
Each blank is to be filled with a numeral of one or more digits, written in decimal notation. Answered by Claude Tardif. 





Two ferry boats 
20010325 

From Gil: Two ferry boats leave from opposite shores. One is faster than the other. They meet 720 yards from the nearest shore. They proceed to destination and upon returning they meet 400 yards from the other shore. What is the exact width of the river. Answered by Penny Nom. 





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. 





problem of the week 
20010306 

From Peggy Allan: My son has been challenged with "the problem of the week" and I am unable to assist him in finding a reasonable solution. Problem 1, Julio needs to draw a line segment 15cm long. He does not have a ruler. He does have some sheets of letter size paper 28 X 21.5 cm. Describe how Julio can use the paper to measur 15 cm. Answered by Claude Tardif. 





23 + 17 * 2 / 8 + 11 = 13 
20010202 

From David: My child is working through basic operations, and gave this problem: 23 + 17 * 2 / 8 + 11 = 13 The teacher wants the parenthesis to be put in the right places to come up with 13. Answered by Claude Tardif. 





Unscramble these words 
20010130 

From Myosha: Hi my name is Myosha. I would be part of the secondary(6~9) class. I need you to unscramble these words & define them for me.  edicnreeff
 rtgeare
 itfrnoca
 lmicdae
 sdvioini
 imrretepe
Answered by Claude Tardif. 





8, 4, 2, 18, 1, 9 
20010111 

From Neyra: Place each number below in one of the blanks to create the most meaningful and realistic story possible. Answered by Claude Tardif. 





Pizza delivery 
20001207 

From Meghan: 3 men give 10 dollars each to a pizza deliver driver and when he gets back to his work the manager says to the pizza driver the bill was actually 25 dollar so he has to returns 5 dollars. on his way to the mens house he the driver decides to kept 2 dollars for himself and he gives 1 dollar back to each of the men. So each one of the men actually paid 9 dollars. but 9 times 3 is 27 plus the other 2 that the driver took equals 29 so where did the other dollar go. Answered by Harley Weston. 





Tapes and CD's 
20001022 

From Arnold: Nicole has 25 CDs and tapes altogether. When she tries to pair them up, she has 4 CDs left over. How many tapes does Nicole have? Answered by Penny Nom. 





Transporting bananas 
20001018 

From Krystie: A farm has 45 bananas, a man has to take a truck and transport 15 bananas to a market that is 15 miles away. Every mile he travels, he must eat a banana. I have to get at least one banana to the market Answered by Penny Nom. 





Cutting the cake 
20001005 

From Cherie: How can you divide a cake (circle) into 14 pieces by using only 4 straight lines? Answered by Penny Nom. 





Selling chickens 
20000912 

From Rick: A man raised chickens. He sold all but 8 of them. The first buyer bought 1/3 of all the chickens + 2/3 of a single chicken. The second buyer bought 1/3 of the remaining chickens + 1/3 of a single chicken. The third buyer bought 1/3 of the remainder + 2/3 of a chicken. How many chickens did the seller own before selling any? All chickens were alive and whole when the buyers received them. Answered by Penny Nom. 





A number problem 
20000902 

From Lalita Balu: Can you arrange 1234567890 to add up to 100? Answered by Penny Nom. 





Three pattern questions 
20000822 

From Michael Rodriguez: I have 3 pattern questions that I need help answering, please.  6 and 7 = 42
2 and 5 = 10 4 and 8 = 8 5 and 9 = ?  7 and 5 = 1
9 and 12 = 3 10 and 15 = 5 12 and 16 = ?  1st = 1
3rd = DEF 10th = * 6th = ? Answered by Claude Tardif. 





Searching for socks 
20000426 

From Luther Jackson: There are 10 red socks and 10 blue socks in a drawer. Aside from their color the are identical. All of the socks in the drawer are mixed up. If the room was pitch black, How many socks would you need to pull out of the drawer to be certain that you have a pair that matches? Why? Answered by Penny Nom. 





Paying with silver 
20000426 

From Luther Jackson: A silver prospector is unable to pay his March rent in advance. He owned a bar of pure silver, 31 inches long, so he made the following arrangement with his landlady. He would cut the bar, he said into smaller pieces. On the first day of March he would give her and inch of the bar, and on each succeeding day he would add another inch to her amount of silver. She would keep this silver as security. At the end of the month, when the prospector expected to be able to pay his rent in full, she would return the pieces to him. . . . Answered by Claude Tardif and Penny Nom. 





Magic triangles 
20000411 

From Sandy: My tutoring student brought math homework today in the form of a "magic triangle". There are three spaces along each side for missing numbers. The sums of the numbers along each of the 3 sides should be the same. Use the numbers 4 through 9. Don't use any number more than once. The sum of the numbers on each side should be 20. What is the logic behind solving a problem of this kind? Answered by Claude Tardif and Harley Weston. 





White and blue paint 
20000409 

From Lauren Emerson: A truck full of cans of blue and white paint flips over on the road. There are dots of blue and white paint everywhere. Prove that two dots of the same color paint are exactly pi feet apart. Answered by Penny Nom. 





What's the next term? 
20000229 

From Meredith O'Neill: At this point, the whole family wants to know the answer. if possible an explanation. thanks a sequence ? 16,37,58,89,145 ?? Answered by Chris Fisher. 





Weighing bales 
20000215 

From Thinh Than: You have 5 bales of hay. and they were weighed but they didn't weigh them individually, they were weighed in pairs. The pairs were 1&2, 1&3, 1&4, 1&5, 2&3, 2&4, 2&5, and so on. The weights of the pairs were 80,82,83,84,85,86,87,88,90, and 91. Can you tell me how much the bales weigh individually. Answered by Claude Tardif. 





Euclidean Math puzzle 
20000124 

From Margaret Matthews:
(Check out this website: Simeon's Triangle Puzzle ) I have tried to figure out how this could be, because everything I know about it tells me it can't be. However, I can't seem to make it NOT work. Two right angle triangles. They are each cut up into four identical pieces. In the first, all the pieces fit together so that there are NO empty spaces; in the second, presumed to be identical in size to the first, the pieces are slightly rearranged, and now, there IS a space in the triangle. Answered by Patrick Maidorn and Claude Tardif. 





Frogs and lily pads 
20000123 

From Nick: There are 5 lily pads and 4 frogs, 2 Red and 2 Green, how many moves does it take for them to swap sides? Answer: 8 I have a formula which will tell you how many moves it will take with different total numbers of frogs, it is [(F*F)/4]+F Where F is the number of red frogs add the number of Green frogs. This formula only works with numbers of frogs that are the same on each side. What I would like to know is why this formula works and why you have to divide it by 4? Answered by Penny Nom. 





An unbelievable story 
20000117 

From Melissa: good morningi am taking a course "math for elementary teachers" and i have a take home problem that i really need help on. here is the question the million dollar problem a recent item in the newspaper described a robbery in which the robber had held up a local bank for 1 million dollars in small bills, had the tellers put the money in a briefcase which he gave them, and fled the scene on foot. is this story believable? explain your answer! Answered by Harley Weston. 





A three digit number 
20000113 

From Manali Shah: My son is in 5th grade, he has a math problem. There is three digit number, which is greater than 500, can be divided by 7,9 and 11, but cannot be divided by 2,4,6, and 5. Answered by Harley Weston. 





How many coins is one calculator? 
20000109 

From Mandy Brockmann: Tom weighed 1 pen and his calculator with 4 coins. Then he weighed his calculator and 3 pens with 12 coins. How many coins is one calculator? Answered by Claude Tardif. 





Cutting a carpet 
19991215 

From Heather: A rectanglular piece of carpeting is 90 inches long and 90 inches wide. How can the carpet be cut into two pieces of equal sides and shape to cover an area of 100inches? There can only be one cut and no scraps. Please show me how. Answered by Penny Nom. 





Passing trains 
19991210 

From Nancy: Two trains, each of 80 cars, must pass on a single track which has a deadend siding. How can they pass if the siding can only hold a locomotive and 40 cars? I do not understand this...help. It will be due monday. I thought it would be simple if the siding could hold 80 cars. Answered by Penny Nom. 





Camels and bananas 
19991202 

From Marie Rich: Corey Camel's harvest, worth its weight in gold, consists of 3000 bananas. The market place where the stash can be cashed in is 1000 miles away. However, Corey must walk to the market, and can only carry up to 1000 bananas at a time. Furthermore, being a camel, Corey eats one banana during each and every mile she walks (so Corey can never walk anywhere without bananas). How many bananas can Corey get to the market? Answered by Claude Tardif. 





A goofy clock 
19991120 

From Kate: While repairing a watch, a jeweler removed the hands and inadvertently replaced the hour hand on the min. spindle and vice versa. he set the hands to read 2:00pm, which was the correct local time when I picked up the watch. A few minutes later, I noticed that the hands were taking goofy positions. What was the first time thereafter that the watch would show the correct local time? Answered by Chris Fisher. 





Selecting some players 
19991120 

From Korbin Brown: Roger Craig, during his term as team manager of the San Francisco Giants, received a strange communication from the team general manager, Al Rosen. Mr. Rosen told him to select 25 players according to this formula: 1/2 of the team had to be outfielders and infielders 1/4 of the team had to be starting pitchers 1/6 of the team had to be relief pitchers 1/8 of the team had to be catchers Roger was a bit confused by Al's request, yet complied anyway. How did he do it? Answered by Claude Tardif. 





Mean, median and mode 
19991106 

From Rick: I have five number places and the mean and median are both "0". The mode is greater than the mean. The sum of the absolute values of all of the numbers is 20. The smallest number is 4 less than the next smallest number. What are the five numbers. (negative integers can be used) All of the numbers are integers. Answered by Penny Nom. 





Cutting a board into 8 equal pieces 
19991021 

From Brittany: Jamie wanted a board cut into 8 equal pieces. The Lucas Lumber Co. charges 60 cents for cutting a board into 4 equal pieces. How much will it charge for cutting Jamie's board? Answered by Claude Tardif. 





Find the missing numbers 
19991012 

From Bonnie: I must find the missing numbers and function rules n  output  7  10  12  20  39  40  24  30  16  b  87  c  we are totally confused can someone help Answered by Denis Hanson. 





A famous mathematician 
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. 





Dollar Bills 
19990927 

From NRQT: Why are 1999 American dollar bills worth more than 1997 American dollars bills? This has to be put into a mathematical problem??? Answered by Penny Nom and Claude Tardif. 





Bob and his dad 
19990914 

From Yvette: "Bobs dad is 27 yrs older then Bob. The sum of their ages 5 yrs ago was 45 yrs. How old is Bob now?" Answered by Penny Nom. 





Six toothpicks 
19990914 

From Maddie: The book asks: Using 6 toothpicks represent the number 17. I am studying expressions to represent a number. ex.) (2+4)4x4=96. Answered by Penny Nom. 





Two Jugs 
19990914 

From Kynadi Kemp: If you have and 8 liter and a 3 liter jug and you want exactly 4 liters how do you get it if there is a water hose near by but thats all you have to get the 4 liters how do you do it ????? Answered by Penny Nom. 





Bales of hay 
19990913 

From Ivy: You are given 5 bales of hay. Two bales are weighed at a time, which equal the following weights: 110, 112, 113,114,115,116,117,118,120,121. What does each individual bale weigh? Answered by Harley Weston. 





2,5,8,1 yields 24 
19990912 

From Terry Hill: I was wondering how do I make the numbers 2,5,8,and 1 equal 24? Answered by Penny Nom. 





Four fours 
19990909 

From Roger: I need help with a math problem my child asked me about I guess in her 7th grade math class they were told to come up with a answer from 110 only using four 4's and she got stuck on the problem that needs to be equal to ten, she asked me and I couldn't help her it's sad so if you could give me the problem and and answer so i could explain it to her I would really appreciate it. Answered by Penny Nom. 





Towers of Hanoi 
19990903 

From Jeni: In the puzzle called the Towers of Hanoi there are three peg and you are asked to move the rings from one peg and stack them in order on another peg. You can make as many moves as you want, but each move must consist of moving exactly one ring. Moreover, no ring may be placed on top of a smaller ring. The minimum number of moves required to move n rings is 1 for 1, 3 for 2 rings, 7 for 3 rings, 15 for 4 rings, and 31 for 5 rings. Find a formula for this sequence. What is the minimum number of moves required to move 6 rings? Answered by Penny Nom. 





How to carpet a room 
19990531 

From Appleby: A room which is 9X12 is to be covered with carpet but the carpet has been provided in one 8X1 piece and one 10X10 piece. The larger piece is to be cut into two pieces so that the room can be covered in carpet. Answered by Stacey Wagner. 





Three Daughters 
19990518 

From Norm Campbell: I recently received a beat up copy of the three daughters question. I have only some of the question. It ends after the statement "the oldest one looks....... It does not finish. Is there any chance that someone can finish it off for me? Answered by Rick Seaman and Harley Weston. 





A Puzzle 
19981027 

From Bruce Bragnu: We are trying to solve what SHOULD BE a simple 7th grade problem and have run into a wall. It is: ABCD ABCD ABCD ABCD  EBEA It is an addition problem. Each particular letter represents the same digit. We are looking for what number "B" represents. We have tried a multitude of solutions and have come up empty. Answered by Penny Nom. 





Tangrams 
19980224 

From Allison: Do you know the story behind the tangram? I know that it is a Chinese puzzle about 200 years old. If there is a story about its creation, I would love to share it with my 7th graders. Thanks. Answered by Diane Hanson and Penny Nom. 





Pentominoes 
19961114 

From Sam Maraldo: What is a pentominoe? I need to understand the concept and how/why it is used? Answered by Penny Nom. 





Will this always yield a palindrome? 
19960828 

From Andy Golden: My friend Justin Skywatcher, said that when his children were in 6th grade, they were taught that if you take any number, reverse it and add the two together, a palindrome will result. If not, continue performing the above operations, and a palindrome will eventually result. Will this always yield a palindrome? Answered by Chris Fisher. 





Magic Square 
19951020 

From Marianne and Carrie: How can an 8 by 8 square have the same area as a 5 by 13 rectangle? Answered by Denis Hanson. 





Énigme 
20080406 

From Frédérique: Tu es dans une pièce ou il y a 3 interrupteurs reliés a 3 lumières dans une autre pièce que tu ne vois pas.Comment faistu pour savoir a quelle lumière chacun des interrupteurs est relié si tu ne peux aller voir dans l'autre pièce qu'une seule fois!Merci a l'avance!!! Answered by Claude Tardif. 





un jardinier plantent 10 arbres 
20070930 

From yannick: un jardinier plantent 10 arbres.il a reussi a les disposer en formant 5 ligne de 4 arbres. retrouver une disposition possible Answered by Claude Tardif. 





Illusion géométrique 
20070404 

From Dominique: Je n'arrive pas expliquer la modofocation de surface. Answered by Claude Tardif. 





Avec les chiffres 1 3 4 6... 
20050414 

From Ambre et Miel: avec les chiffres 1 3 4 6 utilisé une seule fois chacun soit en div multipl addit ousoustr je dois avoir 24 comme résultat Answered by Claude Tardif. 

