Naomi has 5 trophies. In how many different ways can Naomi line the trophies up on her shelf?

This problem states that there are 5 trophies and the problem requires to determine the number of ways Naomi can line up her trophies. In this case, the formula using counting is 5 * 4 * 3 * 2 * 1. there is a decreasing trend as the number of trophies chosen to line up next is decreased by one each time. The answer is 120 ways.