Mr Tommy bought some pizzas for a group of children. There was an equal number of girls and boys. The girls received 4 times as many pizzas as the boys. Each boy ate ¹₅ of a pizza and the boys finished all the pizzas given to them. Each girl ate ¹₁₀ of a pizza and the girls had 13³₁₀ pizzas left. How many pizzas did Mr Tommy buy?

	Girls (1)	Boys (2)
Before	4 u	1 u
Change	- 1 p	- 2 p
After	133	0

¹₅ = ²₁₀

Cutting the slices of pizzas into same size. Each pizza was cut into 10 slices. Every girl ate 1 slice of pizza and every boy ate 2 slices of pizza.

Number of slices that the girls had left
= 13³₁₀ ÷ ¹₁₀ 
= ¹³³₁₀ x 10
= 133

4 u - 1 p = 133 --- (1)

1 u - 2 p = 0
1 u = 2 p --- (2)

Make u the same.

(2)_x4
4 u = 8 p --- (3)

Substitute (3) into (1).
4 u - 1 p = 133
8 p - 1 p = 133
7 p = 133

1 p = 133 ÷ 7 = 19

Total number of slices of pizzas for girls
= 133 + 1 p
= 133 + 19
= 152

Total number of slices of pizzas for boys
= 152 ÷ 4
= 38

Total number of slices of pizzas for children
= 152 + 38
= 190

Total number of pizzas that Mr Tommy bought
= 190 ÷ 10
= 19

Answer(s): 19