A group of friends ordered two pizzas, one with pepperoni and one with mushrooms and green peppers. A plain pizza costs $9. Each topping costs $1. How much did the two pizzas cost?

The cost of 2 pizza is:

$ 21

Step-by-step explanation:

It is given that:

A plain pizza costs $9.

Each topping costs $1.

Also, a group of friends ordered two pizzas.

This means that the cost of two plain pizzas will be: $ (9*2)

i. e.

Cost of two plain pizzas will be: $ 18

Also, there are three toppings in total.

(Pepperoni, mushrooms and green peppers)

This means that cost of three toppings = $ (1*3)

i. e.

Cost of three toppings=$ 3

Hence, Total cost of 2 pizza=Cost of 2 plain pizza+Cost of 3 toppings

i. e.

Total cost of 2 pizza=$ 18+$ 3

i. e.

Total cost of 2 pizza=$ 21

The two pizzas would cost $21 all together.