### Writing a recursive algorithm

The question of how many ways a committee of 4 people can be selected from a group of 10 is known as a combination. The notation in general for counting the number of ways of selecting r items from a group of n is C(n,r) = n! / r!(n-r)! Also, given that 0! = 1 by definition, we can show that C(n,0) = 1 = C(n,n) Also, C(n,r