Another Combo Q: A committee of students and teachers is bei

A committee of students and teachers is being formed to study the issue of student parking privileges. 15 staff members and 18 students have expressed an interest in serving on this committee. In how many ways could a five person committee be formed if it must contain at least one teacher and one student?

Come on!

You show us some work!
You have to do something before we do.

One approach (not necessarily the best, but the first that comes to mind) is finding the number of combinations of one teacher and four students. Then finding the number of combinations of two teachers and three students. And so forth. Then add the four different numbers.

Eliz.