X > Y question

This topic has expert replies
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Mon Mar 15, 2010 4:02 pm

X > Y question

by anthoj » Mon Mar 15, 2010 4:06 pm
Is x > y?

(1) x + y < 0
(2) x - y > 0

The right answer is supposed to be B, but I think it should be D. Here's how I came to that conculsion.

(1):
x + y < 0
so x < -y
so x > y <- is this wrong??
SUFFICIENT

(2):
x - y > 0
so x > y
SUFFICIENT

So, where did I go wrong?

Thanks in advance for any help offered.

Master | Next Rank: 500 Posts
Posts: 216
Joined: Mon Dec 21, 2009 10:26 am
Thanked: 16 times

by student22 » Mon Mar 15, 2010 5:01 pm
For statement 1:

X = -7
Y = -5

-7 + -5 = -12

-12 < 0 , but Y > X.

Basically, the problem with that statement is that X and Y are interchangeable.

Junior | Next Rank: 30 Posts
Posts: 25
Joined: Sat Mar 06, 2010 9:43 am
Thanked: 2 times
Followed by:1 members

by jpjp » Mon Mar 15, 2010 5:37 pm
anthoj wrote:Is x > y?

(1) x + y < 0
(2) x - y > 0

The right answer is supposed to be B, but I think it should be D. Here's how I came to that conculsion.

(1):
x + y < 0
so x < -y
so x > y <- is this wrong??
SUFFICIENT

(2):
x - y > 0
so x > y
SUFFICIENT

So, where did I go wrong?

Thanks in advance for any help offered.
for (1), you made the negative sign disappear from your 2nd to last step to your last step. It shouldn't just disappear like that. If you switch the direction of the > sign, then the other side becomes negative .. so either x<-y or -x>y .. but negative sign doesn't go away