@Ankoganit Here's the question that I was telling you about.
3 schools send 2,4,6 students to a summer camp. These 12 students have to be admitted into 6 rooms numbered 1-6 such that 2 students occupy each room and they must be of the same school. How many possible ways can they be arranged?
@Sid Okay, first assign a school to every room: that's (6C3)(3C2)(1C1) ways; and then we can make "inter-school switches" so that's a factor of (6C2)(4C2)*(4C2). So (6C3)(3C2)(6C2)(4C2)*(4C2) should be the answer, unless I messed up.
