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I thought DS statements should never contradict each other. You are getting y>0 in the first statement, and this clearly contradicts statement 2.manjithmanohar wrote: 1. z < x (if it is considered with the inequality both z and x are negative and that y is positive.) so proves |z| > |x|, hence true.
2. y < 0 (when fit into the inequality proves that again |z| > |x|) so true.
Nicely spotted - that's a typo in the original post, and in the real version of the question, Statement 2 reads "y > 0". The question is from GMATPrep; there's a screenshot of the question here:bluementor wrote:I thought DS statements should never contradict each other. You are getting y>0 in the first statement, and this clearly contradicts statement 2.manjithmanohar wrote: 1. z < x (if it is considered with the inequality both z and x are negative and that y is positive.) so proves |z| > |x|, hence true.
2. y < 0 (when fit into the inequality proves that again |z| > |x|) so true.
As Ian mentions in his post, this is a strange question.
-BM-
I just got this question on my prep test today and spent about 10 minutes after the test trying to figure out why I would need either of the statements to answer the question stem...until, of course, i found this post (and others like it - https://www.manhattangmat.com/forums/pos ... tml#p30742)Ian Stewart wrote:I posted a solution to this to another forum, so I'll just paste that here:
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This is one of the strangest questions in GMATPrep, since you don't need either of the statements to answer the question. That's not supposed to happen on a GMAT DS question, which makes me wonder whether there was an error in the question design. In any case, we're given:
zy < xy < 0
Rewrite this as three inequalities:
(1) xy < 0
(2) zy < 0
(3) zy < xy
From (1), we have two possibilities:
(A) x is positive, and y is negative. Then, from (2), z is positive, and from (3), dividing by y and reversing the inequality because y is negative, we have x < z. So it may be that y < 0 < x < z .
(B) x is negative and y is positive. Then, from (2), z is negative, and from (3), dividing by y, we have z < x. So it may be that z < x < 0 < y .
Those are the only two possibilities here. Draw the number line in each case:
(A)
--------y-------0--------x--------z----------
(B)
-z--------x-----0---------y------------------
In either case, we can see that the distance from z to zero is equal to the sum of the distance from x to zero and the distance from x to z. That is, in either case, |z| = |x| + |x - z|. So we don't need any additional information to be sure that the answer to the question is yes - neither of the statements is required here.
I suppose that makes the answer 'D', though it's the only question I know of in any official GMAT material (and I've seen pretty much every question) where the statements aren't needed to answer the question given.
