At a track event, there are eight different top-ranked runners. How many different ways are there for the eight runners to finish the race?
This problem can be solved by using a factorial. Factorials help you find permutation – all the ways an event might turn out. Factorials are calculated by finding the product of a whole number and all the whole numbers less than that number. 8! = 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 = 40,320. Therefore, there are 40,320 possible ways the eight runners could finish the race.