I don’t understand the question: so they want to know who is in the group of juniors, who is in the group of males and who is both? that’s summing those groups, right? I don’t understand the way the question is asked.

The question is asking for J \cup M, where *J* and *M* represent juniors and males respectively. So that’s J + M - J \cap M.

To @Leaderboard 's point, I would solve this one the following way: 860+270-182=948, i.e. option C.