how many ways can a 3 person committee be formed from 12 people

Answer 1

C(12,3)
= 12!/(3!9!)
= 220

Added attraction:
Google Pascal's triangle
look at the row: 1 12 66 220 495 ....

here is a good one..
http://ptri1.tripod.com/

Answer 2

Two committees, one with six and one with seven people, with no one person serving on both committees at the same time. In how many ways can this be done.