Hi shibsriz,

This is a fairly straight-forward DS question. Let's use TEST IT and some Number Property rules to beat it:

The prompt asks "Is x > y ?" This is a YES/NO question; we know NOTHING about the 2 variables.

Fact 1 tells us that x = y -1

so.... x + 1 = y This means that y is ALWAYS greater than x (by 1).

Is x > y? No, it NEVER IS. The answer is ALWAYS NO. This is consistent, which means....
Fact 1 SUFFICIENT.

Fact 2 tells us x/3 = y -5

If x = 3, then y = 6 Is x > y? NO.
If x = 9, then y = 8 Is x > y? YES.

This is inconsistent, which means....
Fact 2 is INSUFFICIENT.

Final Answer: A (1 only is Sufficient)

GMAT assassins aren't born, they're made,
Rich