Question

In how many ways can 13 people be divided into four groups with 3, 6, 2 and 2 people respectively?

Answer 1

6227020800

Explanation:

There are 13 ways to choose the first person in the first group, 12 ways to choose the second person in the first group and so on until we get 1 way to choose the second person in the last group so the answer is 13 * 12 * 11 * ... * 3 * 2 * 1 = 13! = 6227020800.