Presley has 6 books. There is enough space on a shelf for 4 books. In how many ways can 4 of the 6 books be arranged on the shelf?

6 books to start, then 5, then 4, then 3 so: 6 x 5 x 4 x 3 so 30 x 12 360

4*6=24, so I believe the answer is 24, but I am not certain.