Martin randomly selects 3 days of the week to work at his uncle's farm.

What is the probability he selects Monday, Tuesday, and Friday in any order?

A week has 7 days. That is, number of total days, n = 7

Number of Mondays in a week = 1

Number of Tuesdays in a week = 1

Number of Fridays in a week = 1

This is a case of selecting without replacement in that order.

P (Monday) = 1/7

P (Tuesday) = 1 / (n-1) = 1 / (7-1) = 1/6

P (Friday) = 1 / (n-2) = 1 / (7-2) = 1/5

P (Monday, Tuesday, and Friday) = (1/7) * (1/6) * (1/5) = 1/210