A new school randomly assigns a five-character student code to every prospective student. The school uses the characters 1, 2, 3, 4, 5, W, X, Y, and Z. If none of the student codes contain a repeated character, the total number of codes that can be randomly assigned is 15210.

A yogurt shop allows its customers to add, for no charge, 3 toppings to any yogurt purchased. If the store has 18 possible toppings, there are a total of 816 three-topping combinations.