## Thinking Mathematically (6th Edition)

The number of possible combinations if r items are taken from n items is nCr =$\frac{n!}{r!(n-r)!}$ The number of ways that six jokes can be ordered is: = 6C6 x 6! =$\frac{6!}{(6-6)!6!}$ x 6! =$\frac{6!}{6!}$ x 6! =1 x 6! = 720 ways