The math club needs to select a President, Vice President, Treasurer and Secretary from their 20 members. How many ways can they do this?

Question

The math club needs to select a President, Vice President, Treasurer and Secretary from their 20 members. How many ways can they do this?

Answer 1

This is equal to the number of permutations of 20 items, taken 3 at a time.

20 * 19 * 18 = 6,840.

Another way to think about it is that the first position can have 20 possibilities. The next position can have 19. And the third can have 18. Taking the product gives us the total number of ways they can be assigned.