This is a permutation, not a combination, since the order matters. For instance, "Jim, Bob, Bill, Ted" is not the same as "Bob, Bill, Jim, Ted", even though the same 4 people were used.
So,
9p4 = 3024
But I used advanced probability and statistics to solve (using combinations), so I doubt this will help you. But the answer is correct.
Comments
This is a permutation, not a combination, since the order matters. For instance, "Jim, Bob, Bill, Ted" is not the same as "Bob, Bill, Jim, Ted", even though the same 4 people were used.
So,
9p4 = 3024
But I used advanced probability and statistics to solve (using combinations), so I doubt this will help you. But the answer is correct.
just multiply 4 times 9... the answer is 36