manhattan age problem

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manhattan age problem

by resilient » Fri Mar 07, 2008 7:52 pm
jane started baby-sitting when she was 18 yrs old. However, she only baby sat children who were, at most, half her age. Jane is currently 32 eyars old, and she stopped baby sitting 10 yrs ago. What s the current age of the oldest person that Jane could have baby sat?

qa is 23, I got the answer of 21.
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Re: manhattan age problem

by netigen » Fri Mar 07, 2008 8:53 pm
Enginpasa1 wrote:jane started baby-sitting when she was 18 yrs old. However, she only baby sat children who were, at most, half her age. Jane is currently 32 eyars old, and she stopped baby sitting 10 yrs ago. What s the current age of the oldest person that Jane could have baby sat?

qa is 23, I got the answer of 21.
You will get the answer if you go by her lower age = 18

when she was 18 the kids she baby sat will be 9 or above

So add 14 (32-18) to 9 = 23

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how about this

by resilient » Sat Mar 08, 2008 12:00 am
I see your point. However, I am stuck on the older of the two age groups. What if I add the 14 (32-18) TO THE OLDER age of 11. This yields the answer of 25. I am stuck on that now!
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Re: how about this

by Stuart@KaplanGMAT » Sat Mar 08, 2008 7:04 am
Enginpasa1 wrote:I see your point. However, I am stuck on the older of the two age groups. What if I add the 14 (32-18) TO THE OLDER age of 11. This yields the answer of 25. I am stuck on that now!
She was only able to baby sit 11 year olds when she was 22, which is only 10 years ago, so the 11 year olds that she baby sat would only be 11+10 = 21 years old today.

However, she was able to baby sit the 9 year olds when she was 18, which was 14 years ago. If they were 9 years old 14 years ago, they'd be 23 years old today.
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by xilef » Tue Mar 11, 2008 10:56 am
I understand the question, but it is very tricky, because the first time I read it I understood it as asking for the age of the oldest person at the time of babysitting not the currently oldest person that was babysat by Jane. :shock: