1. Given a group of n people. There are C(n, r) ways of forming groups of r out of n.
2. Where C(n, r)=

3. For example, given {Andy, John, Julia}. We want to pick 2 people to give a gift: we can pick {(Andy, John), (Andy, Julia), (John, Julia)}, so there are 3 ways. So we can list and count.
4. Or we could do this with the formula C(3, 2)=

5. C(8, 6)=

So there are C(8,6)=28 ways of chosing 6 out of 8 people to form the subcommittees. <span />