Gmatprep

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 132
Joined: Tue Oct 07, 2008 4:59 pm
Thanked: 4 times

Gmatprep

by vladmire » Tue Feb 10, 2009 12:02 pm
I can't seem to figure out how to statement 2 is sufficient,
I don't know if x is positive or negative.
I know I need to rearrange the question stem but to what?
Attachments
he.doc
(63.5 KiB) Downloaded 90 times

User avatar
Site Admin
Posts: 2567
Joined: Thu Jan 01, 2009 10:05 am
Thanked: 712 times
Followed by:550 members
GMAT Score:770

by DanaJ » Tue Feb 10, 2009 1:02 pm
The question here is whether x - y > x + y, which is equivalent to -y > y (I subtracted x from each side). This is the case only when y is negative. Let me give you a few examples:
a. if y = 10, then -y = -10, which is smaller than 10 and therefore does not fit the description
b. if y = -5, then -y = -(-5) = 5, which is indeed greater than -5 and fits the initial restriction.

Now, let's analyze each stmt:
1. x = 8, but x - y > 10 means that 8 - y > 10 or that -y > 2 or that y < -2. This is consistent with our conclusion that y is negative, so 1 is sufficient.
2. y is negative, which is consistent with our conclusion.

So the correct answer is D