Answer:
792
Explanation:
It's a combination question. The order is of no consequence. Also the fact that there are juniors and seniors is not important either.
So the answer is
12C5
12!
====
(12 - 5)! * 5!
12 * 11 * 10 * 9 * 8
==============
5 * 4 * 3 * 2 * 1
792