MGMAT (Guide 3 pg. 136) Example question.

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Source: — Data Sufficiency |

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by Pilot » Fri Feb 18, 2011 9:14 pm
My answer is A.
1. Sufficient. If x=y, then xy is non negative. xy is not equal to -1.
2. Insufficient. x=0, y=1 ; x=-1, y=1.

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by OneTwoThreeFour » Fri Feb 18, 2011 10:36 pm
Just realized what I did wrong. For (2), when y is -1 the question becomes does x=-1? Guess I gotta keep things in perspective and focus on the question rather than jump right away into the conclusion.