ds 13

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ds 13

by resilient » Sun Feb 17, 2008 11:31 pm
If Sarah was 21 years old exactly 5 years ago, how old was Larry exactly 9 years ago?

(1) Larry is now twice Sarah's age.

(2) Twelve years ago, Jill was 6 years older than Sarah and 20 years younger than Larry.


qa is d.. i chose a
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Re: ds 13

by joshi.komal » Mon Feb 18, 2008 3:18 am
Enginpasa1 wrote:If Sarah was 21 years old exactly 5 years ago, how old was Larry exactly 9 years ago?

(1) Larry is now twice Sarah's age.

(2) Twelve years ago, Jill was 6 years older than Sarah and 20 years younger than Larry.


qa is d.. i chose a
Hi Engin,

This question can be attacked by preparing a table all the variables in question.

so let us have table of ages of 3 people at different times

Now 5 yrs ago 9 yrs ago 12 yrs ago
Sara 21+5=26 21 26-9=17
Larry L
Jill

the question asks how old was larry 9 yrs ago ?
Let L be age of Larry now if you n=know L you can find out the answer. So the rephrased question will be. 'What is L?' But GMAT is not going to give you a simple answer :). So you should think about llik 'What is the relationship betwee Sara's age and L?' Because you know Sara's age so if you an equation containing S and L you can find out L? So your two rephrased question would be :

What is l ? or What is the relation between Sara's age and L?
Any statement which answers any of these two questions would be sufficient.

1. L= 2(Sara's Age) (answers out question) Hence sufficient. so eliminate BCE.

2. Using J to relate L and S
Now 5 yrs ago 9 yrs ago 12 yrs ago
Sara 21+5=26 21 26-9=17 26-12= 14
Larry L
Jill J

J-12 = 14 +6 ................ (1)
J -12 = 20
J = 20+12 = 32
Given

J -12 = (L -12) - 20
20+20+12 = L
52 = L

So Answer is D

hope this helps

Thanks
Komal