If x and y are positive, is x < y?
(1) √x < √y
(2) (x−3)^2 < (y−3)^2
Source : GMATPREP Exam Pack 2
OA=A
(1) √x < √y
(2) (x−3)^2 < (y−3)^2
Source : GMATPREP Exam Pack 2
OA=A
Hi ziyuenlau,
This prompt is based on a couple of Number Property rules - and you can TEST VALUES to solve it.
We're told that X and Y are POSITIVE. We're asked if X is less than Y. This is a YES/NO question.
1) √X < √Y
Since we know that X and Y are both POSITIVE, squaring or square-rooting those values will NOT change the "order" of them. Even if you're dealing with positive fractions, the 'order' will not change.
For example:
√X = 1/4 and √Y = 1/2
X = 1/2 and Y = about .71
Thus, the answer to the question is ALWAYS YES.
Fact 1 is SUFFICIENT
2) (X-3)^2 < (Y-3)^2
While X and Y are both POSITIVE, we could end up with an (X-3) or (Y-3) that is negative though... and that will impact the answer to the question.
IF... X = 2, Y = 10.... then (-1)^2 is less than (7)^2 and the answer to the question is YES
IF... X = 2, Y = 1.... then (-1)^2 is less than (-2)^2 and the answer to the question is NO
Fact 2 is INSUFFICIENT
Final Answer: A
GMAT assassins aren't born, they're made,
Rich
