Data Sufficiency

Since r is positive (so since it cannot be zero), we can divide by r in the question "What is the probability that rs = r?" to get the simpler question "What is the probability that s = 1?"

So it doesn't matter what is in set R, since we only care if we pick a "1" from set S. Since S contains 3 distinct elements, the answer will either be 1/3 if "1" is in set S, or will be 0 if "1" is not in set S.

Statement 1 tells us that the probability that rs = s, so the probability that r = 1 (we can divide by s since it is nonzero) is 1/3. We don't care at all about values in set R, so this Statement is useless information.

Statement 2 tells us that the probability r+s = 2 is 1/9. The only way, if r and s are positive integers, for r+s = 2 to be true is if r = 1 and s = 1. Since Statement 2 ensures that it is possible s = 1, the value "1" must be in set S, and Statement 2 is sufficient.