GMAT Prep DS (Inequality)

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Source: — Data Sufficiency |

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my take on this

by sangeethai » Tue Feb 26, 2008 4:50 pm
Stmt one just mentions that X < 8/9. It could be a range of values below 8/9. It does not give us one definite value for X

Stmt 2 does the exact same thing for Y.

Both stmts together also don't help in determining a definite value for X or Y. Hence E is the correct answer.

Hope this helps.

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Re: my take on this

by Stuart@KaplanGMAT » Tue Feb 26, 2008 6:45 pm
sangeethai wrote:Stmt one just mentions that X < 8/9. It could be a range of values below 8/9. It does not give us one definite value for X

Stmt 2 does the exact same thing for Y.

Both stmts together also don't help in determining a definite value for X or Y. Hence E is the correct answer.

Hope this helps.
It's a little more complicated that this explanation. The problem is that the range of answers provided include values both less than and greater than 1.

(1) x < 8/9

no info about y, insuff.

(2) y < 1/8

no info about x, insuff.

To test them together, let's get a common denominator:

(1) x < 64/72
(2) y < 9/72

so, if we add both sides, we get:

x + y < 73/72

which means that x+y could be less than 1, equal to 1 or greater than 1: insufficient.
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Thanks for the explanation

by sangeethai » Tue Feb 26, 2008 8:58 pm
Thanks for the explanation Stuart. As I was typing my take on the question, I did think that my explanation was too simple for a DS question. It's good to have someone around to give right directions.

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by joshi.komal » Wed Feb 27, 2008 1:46 am