GMATPrep Q7

This topic has expert replies
Source: — Data Sufficiency |

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by acecoolan » Thu Dec 25, 2008 8:08 pm
The question can be rephrased as follows
if x > 0, is x = y - z ?
or
if x < 0, is x = z -y or x + y = z??

So clearly using both 1) and 2), thats what you arrive at
Hence C)

Probably someone can provide a better and simpler explanation ...

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by cramya » Thu Dec 25, 2008 11:48 pm
Hope I got this right!

Q: Is |x| = y-z

Stmt I and II are individually insufficient

Together

From stmt I we know x = z-y
x = - ( y-z)


So the only way |x| = y-z is if

- ( y-z) = y-z

i.e y = z and x=0

But from stmt II we know x<0 and therefore cannot be 0

Hence |x| will never be equal to y-z

Choose C)

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by vittalgmat » Fri Dec 26, 2008 1:05 pm
Check this link for good discussion and Stuart's explanation

https://www.beatthegmat.com/ds-practice- ... 17422.html