Diana Baniak, searching for an Ecology class, knows that it

Last updated: 7/9/2022

Diana Baniak, searching for an Ecology class, knows that it must be in one of ten classrooms. Since the professor does not allow people to enter after the class has begun, and there is very little time left, she decides to try just five of the rooms at random. How many of the possible different selections of five rooms will succeed in locating the class? There are 120 successful selections.