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 Post subject: Logic Problem
PostPosted: Wed May 31, 2006 4:01 pm 
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This a puzzle but not a twisty one so I guess this is the place for it. It is my favourite logic problem. I have copied it exactly as it appeared in a magazine. Please feel free to post the answer but explain how you got to it (no guessing please, there's no prizes). If you don't want to see the answer then avoid any replies below.

COLLEGE REUNION

A mathematican meets an old friend at a college reunion. He asks his friend how he is, if he's married, and how many children he has. His friend tells him that he's happy, married and has three children.
The mathematician then asks: "How old are they?"
"Well," the friend answers gleefully, "I'll just say that the product of their ages is 36."
"That isn't enough information," the mathematician remarks.
"The sum of their ages is the address of the house where we used to play chess," the friend replies.
"That still isn't enough information," complains the mathematician.
"The youngest looks just like me."
At this, the mathematician immediately knows their ages.
What are the ages of the children?


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 Post subject:
PostPosted: Wed May 31, 2006 4:22 pm 
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if we are going by the ages of the children being whole years then, their ages can only be:
6+6+1=13*
6+3+2=11
2+2+9=13*
3+3+4=10
3+12+1=16
4+9+1=14

i think that's them all,
this means that one of these sets that is starred has to be the correct answer as all the others are unique and except those two, that is why the mathematician asked for another clue, (if 13 was unique it would be that set),
so now we know they played chess at no. 13 (useless information really) and that children are either aged 6, 6 and 1 or 2, 2 or 9.
the friend says his yongest looks just like him, chances are the children who are 2 are twins and people dont usually refer to the first born twin as their youngest child but their youngest twin so i would say that 6, 6, and 1 are the ages because this has a clear 'youngest' child

am i right tony?

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 Post subject:
PostPosted: Wed May 31, 2006 4:33 pm 
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Spot on Pembo. Well done. It's surprising the amount of people who get stuck on the chess thing or house number and simply look at it the wrong way. BTW at the beginning the ages could also have been 1,1,36 and 1,2,18


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 Post subject:
PostPosted: Wed May 31, 2006 4:42 pm 
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o yes....i still got it :P
i love brain teasers

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 Post subject:
PostPosted: Fri Jun 02, 2006 2:30 am 
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do i get a puzzle for working that out tony? :lol:

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 Post subject:
PostPosted: Fri Jun 02, 2006 4:47 am 
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Pembo wrote:
people dont usually refer to the first born twin as their youngest child but their youngest twin


Thank you Pembo, I could improve my English with your answer.


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 Post subject: logic problem
PostPosted: Fri Jun 02, 2006 2:56 pm 
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Hi Tony,

No solution.

The childrens pattern of ages could run:
36*1*1=38
18*2*1=21
9*4*1=14
9*2*2=13
6*6*1=13
6*3*2=11
4*3*3=10

I considered that the house was in the back like
6*4*1.5=11 1/2
but that leaves too many possibilities, so I assume whole numbers for the ages.

The two age patterns that add to the same number, 13, have the youngest being two year old twins or a one year old.

Pretty cool puzzle. Although it looks like the one year old would indicate the solution is 6*6*1=13, there is no solution. This is because the young twins could be fraternal twins, a male and a female, with the female born first. The male would be youngest and could resemble his father but he wouldn't necessarily look like his sister.

Cheers,

David J


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 Post subject:
PostPosted: Fri Jun 02, 2006 5:45 pm 
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I don't think who the youngest looks like is relevant. The fact that there is a youngest tells you 2,2,9 is not possible. I know technically one twin is born first and in fact they don't even have to be twins but I think for this kind of problem you have to accept things the way they are meant. The reason I like this problem is because there are no tricks. At first it seems ridiculous but then it all makes perfect sense.


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 Post subject:
PostPosted: Fri Jun 02, 2006 6:55 pm 
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If you make 2 sand piles and your friend makes 6. If you put them together, how many do you have?

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Average: 14.38 seconds

Individual Times: 14.17, 12.93, (12.89), 13.12, 14.00, 15.59, 16.23, 14.11, 14.03, (17.61), 14.75, 14.89


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 Post subject: logic problem
PostPosted: Fri Jun 02, 2006 7:26 pm 
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Hi Tony, (and Peter, and Mike G, and Jaap, and others)

Here's problem for you guys to solve.

If you dropped a one inch diameter ball bearing one foot, gravity would impart a certain amount of energy to it, and it would would attain a certain velocity.

Find the shape of a ramp that will transfer the greatest amount of the motion of that falling ball bearing from the vertical to the horizontal plane. The ramp must fit into a virtual box that measures one foot by one foot by one inch.

In other words, you release the ball at the top of the ramp and it rolls down the ramp, off the ramp, and across the floor. If the floor is uniform the best ramp would have the ball roll the furthest. All things being equal, a ramp designed to bounce the ball (the idea of air having less friction than the floor) is not allowed.

The ramp may be considered to have smooth two parallel tracks for the ball bearing to roll upon.

Plese send me your solution privately.

David J


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 Post subject:
PostPosted: Fri Jun 02, 2006 9:06 pm 
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I think you would have 1 pile Captaincrash.


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 Post subject:
PostPosted: Fri Jun 02, 2006 9:58 pm 
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yes thats right. My friends at school go 2 plus 6 is eight and don't think it through.

I got another...

If you have a bag of 30 oranges and you take one out, how many do you have left?

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Average: 14.38 seconds

Individual Times: 14.17, 12.93, (12.89), 13.12, 14.00, 15.59, 16.23, 14.11, 14.03, (17.61), 14.75, 14.89


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 Post subject:
PostPosted: Sat Jun 03, 2006 2:43 am 
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well you have 29 left, but you are going to say i am wrong that i have 1 left,

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 Post subject:
PostPosted: Sat Jun 03, 2006 7:29 am 
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nope. you still have 30 cuz it's your bag and you just took one out

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Individual Times: 14.17, 12.93, (12.89), 13.12, 14.00, 15.59, 16.23, 14.11, 14.03, (17.61), 14.75, 14.89


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