Question

Indigo is organizing textbooks on her bookshelf. She has a Spanish textbook, a math textbook, and a physics textbook. How many different ways can she line the textbooks up on her bookshelf?

Answer 1

There are 3! = 6 ways. Reason: 3 choices for the first spot, 2 for the second, 1 for the last. The arrangements are:

S M P, S P M, M S P, M P S, P S M, P M S.