S1: Nothing about x; not sufficientNandishSS wrote:Is xy> x/y ?
(1) 0 < y < 1
(2) xy > 1
OA : C
S2: Case 1: x = 2 and y =1: 2*1 is not greater than 2/1, so we get a NO.
Case 2: x = 1 and y = 2: 1*2 is greater than 1/2, so we get a YES; not sufficient
Together: Case 1: y = 1/2 x = 2: (1/2) * 2 is not greater than 2/(1/2), so we get a NO. We could continue to pick numbers, and see that the answer will always be NO to prove sufficiency.
Alternatively, we can use a little logic. S1 tells us that y is a fraction between 0 and 1. S2 tells us, in conjunction with S1, that x and y are both positive. In xy, we're multiplying some positive number (x) by a fraction between 0 and 1 (y) thus making the value smaller. In x/y, we're dividing some positive number (x) by a fraction between 0 and 1 (y) thus making the value bigger. Thus the xy will never be greater than x/y. Together the statements are sufficient. The answer is C.
