Question

How many ways can Ismail arrange four different textbooks on the shelf in his locker?

Answer 1

`4! =24`

Explanation:

There are `4` different choices for the first book, but once that one is in place, there are `3` choices for the second, two for the third and then only 1 book remains to be placed on the shelf last.
This assumes that the books are all different.

The number of possible arrangements is `4xx3xx2xx1 = 24`

This is called '4 factorial' and has the symbol `4!`