He trifecta at most racetracks consists of selecting the first-, second-, and third-place finishers in a particular race in their proper order. If there are nine entries in the trifecta race, how many tickets must you purchase to guarantee a win?

11.7#16

The answer is 504 tickets must be purchase to guarantee a win.

Step-by-step explanation:

This is a permutation problem, which requires arrangement.

The first place finisher can be any of the nine entries, the second place finisher can be any of the remaining 8 entries and the third place finisher can be any of the remaining 7 entries.

Therefore; 9*8*7=504