ildude02 wrote:Is X > Y?
1. SQRT(X) > Y;
2. X ^3 > Y;
Is there any algebraic way to solve this?
I don't think questions like this can be solved algebraically. Besides, such a method would just slow you down... Here's my strategy.
Statement 1: Notice that X = [SQRT(X)]^2. If SQRT(X) is greater than or equal to 1, then surely its squared value will be even greater. Then indeed, X > Y, no matter what the value of Y is.
However, if SQRT(X) < 1, like say, SQRT(X) = 1/2, then it's squared value will be
reduced. Try to work this out with y = 1/3.
INSUFFICIENT
Statement 2: Regardless of whether X is positive or negative, X^3 > Y does not immediately clarify whether X > Y. You can plug in values to test if you need, but most can just tell innately.
INSUFFICIENT
Combined 1 & 2: From Statement 2, we know that SQRT(X) should be equal to or greater than 1 (because X^3 means that SQRT(X) has been raised to power of 6 and it certainly cannot be not reduced).
SUFFICIENT
I choose C. I hope it's the OA.