In the orchestra, there are eight violinists in the
front row. How many
different ways can
they be seated?

Explanation:

We have 8 choices for the first slot, 7 for the second, and so on. We count our way down until we have 1 choice left for the eighth slot.

We'll get 8*7*6*5*4*3*2*1 = 40,320 different permutations.

You could use the nPr formula

with n = 8 and r = 8 to get the same result. The exclamation marks indicate factorials.