3x

Looking only at S2, we have:

-5x < -14y
5x > 14y
3x > (3/5)*14y
3x > 8.4y

So we know that 3x > 8.4y, and we want to know if 3x > 7y. If y is positive, the answer is certainly 'yes', because then 8.4y > 7y. However, if y is negative, 8.4y is less than 7y. We might have:

y = -1
x = -2.5

Then 3x = -7.5 is certainly greater than 8.4y = -8.4, but 3x is not greater than 7y = -7. Statement 2 is not sufficient.

raghavsarathy wrote:
Hi Ian. The main statement says that x and y are positive. In such a situation the ans would be B right ?

Good point! When I was writing up my answer, I think I was remembering a different question that didn't have that restriction. Yes, since:

8.4 > 7

then if y is positive, we can multiply on both sides by y without reversing the inequality to get:

8.4y > 7y

so if x > 8.4y, then x certainly must be greater than 7y. So to clarify my post above, if x and y are positive, S2 is certainly sufficient. If you remove that condition from the question, then S2 is not sufficient.