Mr Eric bought some pizzas for a group of children. There was an equal number of boys and girls. The boys received 2 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 ¹₁₅ of a pizza and the boys had 8¹₃ pizzas left. How many pizzas did Mr Eric buy?

	Boys (1)	Girls (2)
Before	2 u	1 u
Change	- 1 p	- 3 p
After	125	0

¹₅ = ³₁₅

Cutting the slices of pizzas into same size. Each pizza was cut into 15 slices. Every boy ate 1 slice of pizza and every girl ate 3 slices of pizza.

Number of slices that the boys had left
= 8¹₃ ÷ ¹₁₅ 
= ²⁵₃ x 15
= 125

2 u - 1 p = 125 --- (1)

1 u - 3 p = 0
1 u = 3 p --- (2)

Make u the same.

(2)_x2
2 u = 6 p --- (3)

Substitute (3) into (1).
2 u - 1 p = 125
6 p - 1 p = 125
5 p = 125

1 p = 125 ÷ 5 = 25

Total number of slices of pizzas for boys
= 125 + 1 p
= 125 + 25
= 150

Total number of slices of pizzas for girls
= 150 ÷ 2
= 75

Total number of slices of pizzas for children
= 150 + 75
= 225

Total number of pizzas that Mr Eric bought
= 225 ÷ 15
= 15

Answer(s): 15