Data Sufficiency

Set S consists of even number of integers. Is the median of set S negative?

1. Exactly half of all elements of set S are positive
2. The biggest negative element of set S is -1

Statement 2 has wording that would never appear on the test: "biggest" negative number is not clear. Do you mean "most positive" or "most negative." I suspect the question meant "most negative," but "biggest" actually means "most positive." I will answer the question as if it means "most negative."

This is a good candidate for using examples.

Statement 1:
Could be 2, -1 (median = 0.5)
Could be -2, 1 (median = -0.5)
[spoiler]Insufficient
[/spoiler]
Statement 2:
Could be -1, -1 (median = -1)
Could be 2, -1 (median = 0.5)
Insufficient

Combined:
If the "most negative" element is -1, and half the elements are positive, there is no way that there will be enough "pull" from the negative numbers to make the median below zero.

The lowest the median could be is if the set is (-1, 1) in which case the median is 0. For every -1 we add, we would need to add a positive element, which make the median either zero or positive. Since we have a definitive NO answer, it is C.

MO:C