From "Discrete Mathematics with Graph Theory"

by Goodaire and Parmenter

Page 236 # 16

There are 5 single rooms, 5 double rooms, and 5 triple rooms in a college. In how many ways can 30 students be assigned to the 15 rooms? (All rooms are numbered).

Thanks!

I'm thinking theres 15 spots (5 singles, 5 doubles, 5 triples) and 30 people go into those spots. But Then I'm confused from there.