134 DS with modulus

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Re: 134 DS with modulus

by thermcin » Tue Oct 06, 2009 5:02 pm
ern5231 wrote:1)X is a positive integer and Y is a negative integer. Is |XY|=3?

(1) | x+y | = 3
(2) | |x|-|y| | = 3


Answer is D.

The stem asks if |XY| = 3,

when will a product of two integers equal 3?

only if one of them is +-1 and the other is +-3

Since we know X is +ve, X could be +3 or +1 and Y could be -1 or -3.

Now look at Statement (1) |X+Y| = 3

with the possible values of X and Y, it is clear that statement 1 cannot be satisfied. So |XY| is not equal to 3

Statement 2 is basically the same as statement 1.



2) Is x> y?

(1) IxI > IyI
(2) Ix-yI = x - y


Statement 1 is insufficient.
Statement 2 would only be true if X > Y. So answer is B.

Let me know if these answers are correct.

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by crackgmat007 » Tue Oct 06, 2009 9:46 pm
1. D

2. B

Same calculations as above.