ans should be A

Mean = Sum / No of terms.

Since the sum is the same for both the sets and the avg of one is less than the other. The one with the lower avg will have greater terms.

pls confirm

Ur correct again but why is it A and not B since we don't really have any information in either of the two.

B cannot be right because although statement 2 tells us which median is greater we have no way to tell which list has more integers. The lists could be S={1,3,4} and T={0,1,7} (S has greater median but sum of lists are equal). In this case S does not contain more integers than T. However the lists could instead be S={0,3,3,4} and T={0,1,9}. In this case S contains more integers than T.

Thus from the 2nd statement we cannot determine whether S contains more values.

The official answer is A, though I have a problem with statement 1 being sufficient. In effect, I think that the official answer assumes that the sum is positive, something we actually don't know.

Anyway, a fuller discussion and video solution can be found at GMATPrep Question 1335. To create drills with similar questions, set topic='Sets & Groups and Statistics' and difficulty='600-700 & 700+' in the Drill Generator.

-Patrick