Nine mountain bikers are on a bicycle trip. In how many different possible ways can they follow each other?

We could have  9 ways to pick the leader x 8 ways to pick the second place rider x 7 ways to pick the third place rider, etc.

So

9 x 8 x 7 x .....x  3 x 2 x 1  = 9!  = 362880  ways to arrange them