### Home > A2C > Chapter 10 > Lesson 10.2.6 > Problem10-154

10-154.

Find how many types of pizzas with three toppings can be made.

8C3

Find how many pizzas with four toppings can be made.

8C4

8C3 + 8C4 = 56 + 70 = 126

If mushrooms are a known topping, then you choose one fewer topping from only 7 remaining toppings.

$\frac{_{7}C_{3}+_{7}C_{2}}{126}=\frac{56}{126}=\frac{4}{9}$