## Thinking Mathematically (6th Edition)

The number of ways in which a series of successive things can occur is found by multiplying the number of ways in which each thing can occur. ---------- 1. The size of the pizza can be chosen in $3$ ways. 2. The crust type can be chosen in $4$ ways. 3. The topping can be chosen in $6$ ways. Applying the Principle, the total number of pizzas is $3\times 4\times 6=72$