Answer:
210
Explanation:
There are 7 * 6 * 5 ways to finish. This is because we have 3 slots:
For 1st place, there are 7 people that could take that place, so we have 7
For 2nd place, there are 6 people, because one person already took 1st, so they cant be second as well.
For 3rd place, there are 5 people, because 2 people already took first and second place, and neither of them can be third then.
So we have:
7*6*5 = 210