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x-y

by heshamelaziry » Mon Aug 31, 2009 8:34 pm
Does x-y = 200 ?

(1) x=10^2
(2) x=100 and y=-100


Seems very easy, don't understand why choice 1 is incorrect ?
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Source: — Data Sufficiency |
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by tohellandback » Mon Aug 31, 2009 8:55 pm
well,
1 says nothing about Y . thats why 1 is incorrect
for y=-100, x-y will be 200
for y=any other value it x-y will not be 200. Thats why NOT SUFF

2) is SUFF
The powers of two are bloody impolite!!
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by grockit_jake » Tue Sep 01, 2009 1:36 pm
Without an explanation for y, you can't know x - y. (1) is not sufficient because you are missing information on how to find y.
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