Question

You have checked out b books from the library, where b is a number greater than 5. You plan to read three of the books and return them at the end of this week. In how many ways can you pick the books you will read first, second, and third?

Answer 1

There are b books to choose from for your first book to read. There are b-1 books to choose for your second, and b-2 to choose from for the third. The product will be the number of possible ways to choose, b(b-1)(b-2)=b^3-3b^2+2b