Ahhh yes, the time-honored permutations.
The permutation format, to start with, is P(n, r).
The formula is:

In this instance, we have P(8, 3).
8 will go in for n and 3 for r. So now let's solve.
→
→
→
→

Therefore 336 is our answer. I hope this answers your question.
-Toremi