Mr Flynn bought some pizzas for a group of children. There was an equal number of boys and girls. The boys received 5 times as many pizzas as the girls. Each girl ate ¹₅ of a pizza and the girls finished all the pizzas given to them. Each boy ate ¹₁₀ of a pizza and the boys had 13¹₂ pizzas left. How many pizzas did Mr Flynn buy?

	Boys (1)	Girls (2)
Before	5 u	1 u
Change	- 1 p	- 2 p
After	135	0

¹₅ = ²₁₀

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

Number of slices that the boys had left
= 13¹₂ ÷ ¹₁₀ 
= ²⁷₂ x 10
= 135

5 u - 1 p = 135 --- (1)

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

Make u the same.

(2)_x5
5 u = 10 p --- (3)

Substitute (3) into (1).
5 u - 1 p = 135
10 p - 1 p = 135
9 p = 135

1 p = 135 ÷ 9 = 15

Total number of slices of pizzas for boys
= 135 + 1 p
= 135 + 15
= 150

Total number of slices of pizzas for girls
= 150 ÷ 5
= 30

Total number of slices of pizzas for children
= 150 + 30
= 180

Total number of pizzas that Mr Flynn bought
= 180 ÷ 10
= 18

Answer(s): 18