Question

A manager at a store is holding a contest where the first, ninth, and ninetieth customers of the day will win a prize. 100 people visit the store that day. Three different friends visit the store that day. What is the probability that they are the first, ninth, and ninetieth customers of the day? Give your answer as a fraction in simplest form.

Answer 1

Answer: 1/970200

Step-by-step explanation:

This is a permutation problem, because the order matters.

There are 100! ways for the 100 customers to visit the store.

There are (100−3)!=97! ways for the three friends to be the first, ninth, and ninetieth customers