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Guess The Boy's Age by Sam Loyd


Best Answer jhawk, 03 April 2013 - 08:53 PM

Spoiler for My guess

Go to the full post


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7 replies to this topic

#1 BMAD

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Posted 03 April 2013 - 07:41 PM

It appears that an ingenious or eccentric teacher being desirous of bringing together a number of older pupils into a class he was forming, offered to give a prize each day to the side of boys or girls whose combined ages would prove to be the greatest.

Well, on the first day there was only one boy and one girl in attendance, and, as the boy's age was just twice that of the girl's, the first day's prize went to the boy.

The next day the girl brought her sister to school, and it was found that their combined ages were just twice that of the boy, so the two girls divided the prize.

When school opened the next day, however, the boy had recruited one of his brothers, and it was found that the combined ages of the two boys were exactly twice as much as the ages of the two girls, so the boys carried off the honors of that day and divided the prizes between them.

The battle waxed warm and on the fourth day the two girls appeared accompanied by their elder sister; so it was then the combined ages of the three girls against the two boys, and the girls won off course, once more bringing their ages up to just twice that of the boys'. The struggle went on until the class was filled up, but as our problem does not need to go further than this point, to tell the age of that first boy, provided that the last young lady joined the class on her twenty-first birthday. Now, guess the first boy's age.


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#2 jhawk

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Posted 03 April 2013 - 08:53 PM   Best Answer

Spoiler for My guess


Edited by jhawk, 03 April 2013 - 08:55 PM.

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#3 BobbyGo

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Posted 03 April 2013 - 08:59 PM

Spoiler for I think I forget how to maths


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#4 BMAD

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Posted 03 April 2013 - 09:07 PM

It won't let me mark solved for some reason.


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#5 BobbyGo

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Posted 03 April 2013 - 09:07 PM

Clarification?

 

When you say, "the last young lady joined the class on her twenty-first birthday", are you referring to the last lady to join the class after it has been filled up, or the last lady to join the class of the three sisters?


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#6 jhawk

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Posted 04 April 2013 - 12:59 AM

Spoiler for here's how i got my previous answer


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#7 nakulendu

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Posted 04 April 2013 - 10:22 AM

Spoiler for several possibilities


Edited by nakulendu, 04 April 2013 - 10:28 AM.

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#8 nakulendu

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Posted 04 April 2013 - 03:39 PM

Spoiler for My guess

Spoiler for When did the Class fill up...


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