ds4

Morgoth · Posted: Sun Oct 05, 2008 12:14 am Post subject:

IMO C

We just have to find out if x and z both are positive or both are negative and is x> z

Statement (1)
z < x
z and x both could be positive and both could be negative. We dont know anything about y. Insufficient.

Statement (2)
y>0
x and z both are negative but we dont know if x>z or x<z. Insufficient.

Combining (1) & (2)

x and z both are negative, x>z. Sufficient.

Thus, C
OA?

4meonly · Posted: Sun Oct 05, 2008 1:03 am Post subject:

I got A...
I am not sure, but i'll post. may be someone will find a flaw

Main: zy<xy<0

(1)
z<x, so to make zy<xy<0 right y should be positive
because if y will be negative and we will get zy>xy>0
z and x are negative
let z=-5, x=-3
|x-z|+|x|=|-3+5|+|-3|=5
|z|=|-5|=5
SUFF

(2)
y<0
yeah, I know it from (1) but what about z and y?
Insuff

A

Morgoth · Posted: Sun Oct 05, 2008 1:22 am Post subject:

4meonly · Posted: Mon Oct 06, 2008 1:09 am Post subject:

Morgoth · Posted: Mon Oct 06, 2008 5:56 am Post subject:

I made the most terrible mistake again.

I apologize to you "4meonly" I tried to reason with you, presented you with counter argument when it was in fact wrong and you were absolutely correct in your reasoning.

Here is the answer which I think should be correct.

Statement (1)
z<x
if zy < xy <0 , y has to be positive.

Therefore x and z are negative. all the negative numbers satisfy the above equation. Sufficient.

Statement (2)
y>0

if y is greater than 0, then z and x are negative, all negative numbers satisfy the above equation. Sufficient.

Thus, D.

I think this should be the answer. Let me know if anybody thinks otherwise.

Thanks "4meonly" for bringing this question, it has really helped me clear some doubts of my own.

OA?

4meonly · Posted: Mon Oct 06, 2008 6:52 am Post subject:

Morgoth,
no problem. Your posts are helpful for me, too Very Happy

I agree with you that answer should be D Laughing