Hi All,
This DS question is based on a couple of Number Property rules; if you know the rules, then you can answer this question with a more logic-based approach. If you don't know the rules, then you can still discover the patterns involved by TESTing VALUES.
We're asked if X^2 is greater than X. This is a YES/NO question.
By doing a little bit of work up-front, we can make dealing with the two Facts easier. We just have to think about what X COULD be and whether that would make X^2 greater than X (or not).
IF... X = ANY negative value....
Then X^2 = positive and X^2 > X. The answer to the question would be YES.
IF.... X = 0 or X = 1
Then X^2 = X. The answer to the question would be NO.
IF.... X = A positive FRACTION...
Then X^2 < X. The answer to the question would be NO.
IF.... X > 1
Then X^2 > X. The answer to the question would be YES.
Fact 1: X^2 is greater than 1
Here, X COULD be any negative LESS than -1 (eg. -2, -3, -4, -1.5, etc.)....and the answer to the question would be YES.
X COULD also be any positive GREATER than 1 (e.g. 2, 3, 4, 1.5, etc.)...and the answer to the question would also be YES.
The answer to the question is ALWAYS YES.
Fact 1 is SUFFICIENT.
Fact 2: X is greater than -1
X COULD be 0...and the answer to the question would be NO.
X COULD also be any positive GREATER than 1 (e.g. 2, 3, 4, 1.5, etc.)...and the answer to the question would be YES.
Fact 2 is INSUFFICIENT
Final Answer:
GMAT assassins aren't born, they're made,
Rich
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