- Find and prove a formula for the number of subsets of the set .
- For nonnegative integers
*n*and*k*, define to be the number of subsets of size*k*contained in a set of size*n*. Prove thatThen prove that

remembering that we define 0!=1.

- Prove the binomial formula:

Wed Apr 21 08:26:07 EDT 1999