## Thinking Mathematically (6th Edition)

The number of possible permutations if r items are taken from n items is nPr =$\frac{n!}{(n-r)!}$ The number of ways that a person can select their favorite joke told by a woman and their two favorite jokes told by a man is = 2C1 x 4C2 =$\frac{2!}{1!(2-1)!}$ x $\frac{4!}{2!(4-2)!}$ = 2! x $\frac{4!}{2!2!}$ =2*1 x $\frac{4*3*2!}{2!2!}$ =2 x $\frac{4*3}{2*1}$ =2 x 6 =12 ways