Math Is Fun Forum

username

Member

Registered: 2006-01-05

Posts: 4

my math extra credit riddle. HELP PLEASE

so i have a b+ in math so i really need this help gracias.

The holiday-a time for spending time with family and friends. Many years from now two old best friends, hillary and monica, run into eachother during the holidays. They havent seen each other in years.

Hillary: How are you? What are you doing now?
Monica: Im fine, I have three sons now, bill, billy, and william
Hillary: How nice! how old are they?
Monica: The product of their age is 36
Hillary: can you give me another clue?
Monica: Well the sum of their ages is the address of that store over there
(Hillary looked at the store and thought for a few minutes.)
Hillary: I still need another clue.
Monica: Ok. my oldest son likes chocolate ice cream.
Hillary: I've got it now!

What are the ages and how did hillary solve it? Fully explain your answer in paragraph form.

THanks<3

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: my math extra credit riddle. HELP PLEASE

I don't want to give you the answer, because that would just be doing your homework for you, but here are a few clues:

The three ages need to total 36. That means that they can be any of:
1, 1, 36
1, 2, 18
1, 3, 12
1, 4, 9
1, 6, 6
2, 2, 9
2, 3, 6
3, 3, 4

But Hillary doesn't know which of those it is, so she needs another clue.
The information about the shop is actually useful, because you are told that Hillary still doesn't know their ages even after she knows their sum.

And then the last clue helps because you are told that she has an oldest son.

You should be able to get it now.

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Why did the vector cross the road?
It wanted to be normal.

username

Member

Registered: 2006-01-05

Posts: 4

Re: my math extra credit riddle. HELP PLEASE

well its a extra credit so its not reallya homework eh. i dont get what the address of the store has to do with anything

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: my math extra credit riddle. HELP PLEASE

She still doesn't know their ages even when she know what they add up to, so they must add up to something that could be represented by 2 of the sets. Add up all of the sets, and see which ones match. Then choose the one out of those that has an oldest child in it.

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Why did the vector cross the road?
It wanted to be normal.

username

Member

Registered: 2006-01-05

Posts: 4

Re: my math extra credit riddle. HELP PLEASE

possible sums of their ages:
1, 1, 36=38
1, 2, 18=21
1, 3, 12=16
1, 4, 9=14
1, 6, 6=13
2, 2, 9=13
2, 3, 6=11
3, 3, 4=10

so 2, 2, 9=13 right? so two of the children can be the same age?

username

Member

Registered: 2006-01-05

Posts: 4

Re: my math extra credit riddle. HELP PLEASE

well thank you so much! i really appreciate your help

Aubree

Guest

Re: my math extra credit riddle. HELP PLEASE

The answer is 1, 1, 18

Good Luck!

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,711

Re: my math extra credit riddle. HELP PLEASE

The answer is 1, 1, 18

Can't be. Doesn't multiply up to 36.

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Dragonshade

Member

Registered: 2008-01-16

Posts: 147

Re: my math extra credit riddle. HELP PLEASE

username, I think u already worked it out

Since she asked for more clue which means that two possible answer add up to the same sum
Then he told her that he had an eldest son
Which eliminated the other answer

Kayyyy

Guest

Re: my math extra credit riddle. HELP PLEASE

A palindrome is a word or number that reads the sne backrards as it does forward. Numbers like 606 or 4334 are both palindromes. while driving his car, bob(another palindrome) observes that the odometer reading forms a palindrome. It displays the mileage 13,931. Bob keeps driving. Two hours later he looks at the odometer again and, to his surprise, it displays a different palindrome.What is the most likely speed that bob is traveling?

TheDude

Member

Registered: 2007-10-23

Posts: 361

Re: my math extra credit riddle. HELP PLEASE

Last edited by TheDude (2009-01-12 04:29:10)

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Wrap it in bacon

bananas

Member

Registered: 2009-02-11

Posts: 6

Re: my math extra credit riddle. HELP PLEASE

At a party, a guest asks the age of the host’s three children. The host tells the guest the following information: 

Assume each child is a whole number age;

The product of their ages is 72;

The sum of their ages is the same as my house number.

The guest goes outside and looks at the house number. Upon returning, the guest indicates that he still needs additional information.  The host then says "Oops, I forgot to tell you that the oldest is the only one that likes vanilla ice cream."  You now have all the information to determine the ages of the children. How old is each child?

Please help! This is extra credit, and im only a 5th grader

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: my math extra credit riddle. HELP PLEASE

This can be solved in exactly the same way as above.
The numbers will be different, but the method is unchanged.

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Why did the vector cross the road?
It wanted to be normal.

bananas

Member

Registered: 2009-02-11

Posts: 6

Re: my math extra credit riddle. HELP PLEASE

I got it now
is it 3,3,8?

bananas

Member

Registered: 2009-02-11

Posts: 6

Re: my math extra credit riddle. HELP PLEASE

how do you play the game??

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: my math extra credit riddle. HELP PLEASE

3,3,8 seems right to me.

The house number isn't enough because 2,6,6 is another possibility, but then that one's eliminated by the last clue.

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Why did the vector cross the road?
It wanted to be normal.

FranktheTank

Member

Registered: 2009-04-30

Posts: 1

Re: my math extra credit riddle. HELP PLEASE

An added twist to the above riddle.  I'm stuck with the daughters ages

Clue is

1. The north coordinate is 29°45.ABC and the west coordinate is 095°42.DEF.
2. The numbers ABC and DEF run from smallest to largest.
Well, I told myself I can make a thousand guesses but I really don’t know so I went to the cache owner’s home for some hints.
“Can you give me more information about the coordinate decimal minutes?” I said. He replied “The decimal minutes for the north coordinate is the same as the ages of my daughters and the decimal minutes for the west coordinate are the same as the ages of my three sons.
“What are their ages?” I asked. He replied “The product of the ages of my sons is 36. Do you know the coordinates now?”
Thinking for a moment, I answered “No, could you give me another hint?” He said “Can you read the house number over there?”
“Yes I replied!” to which he interjected “The sum of the ages of my sons is the same as the house number. Do you know the coordinates now?”
After thinking for what seemed an eternity, I finally replied “Not really!”
Finally he said “My oldest son geocaches.”
Then I said, “OK, now what about your daughters?” He concluded, “Well, of course they are different from my sons but they are related

rainbow2009

Member

Registered: 2009-05-11

Posts: 1

Re: my math extra credit riddle. HELP PLEASE

Have got the clues. Now everything is going well as it should go
Appriciate your post,FranktheTank

credit01

Member

Registered: 2009-05-25

Posts: 1

Re: my math extra credit riddle. HELP PLEASE

Many thanks, FranktheTank. Now everything is going well with the clue you have posted. It is highly appreciated.

Last edited by credit01 (2009-05-25 13:35:21)