The number of ways a doctor can make his rounds if he has 4 patients and he check each patient once

Question

Give the number of possible outcomes. Show your solution/s.

Answer 1

Since they are making rounds , one patient after another, order matters.

1. First visit there are 4 choices
2. Second visit there are only 3 choices ( 1 has been used up)
3. Third visit there are only 2 choices
4. Fourth visit there is only 1 choice.

Total permutations = 4*3*2*1 or 24