Mr George bought some pizzas for a group of students. There was an equal number of boys and girls. The boys received 2 times as many pizzas as the girls. Each girl ate ¹₆ of a pizza and the girls finished all the pizzas given to them. Each boy ate ¹₁₈ of a pizza and the boys had 8¹₃ pizzas left. How many pizzas did Mr George buy?

	Boys (1)	Girls (2)
Before	2 u	1 u
Change	- 1 p	- 3 p
After	150	0

¹₆ = ³₁₈

Cutting the slices of pizzas into same size. Each pizza was cut into 18 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 ÷ ¹₁₈ 
= ²⁵₃ x 18
= 150

2 u - 1 p = 150 --- (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 = 150
6 p - 1 p = 150
5 p = 150

1 p = 150 ÷ 5 = 30

Total number of slices of pizzas for boys
= 150 + 1 p
= 150 + 30
= 180

Total number of slices of pizzas for girls
= 180 ÷ 2
= 90

Total number of slices of pizzas for students
= 180 + 90
= 270

Total number of pizzas that Mr George bought
= 270 ÷ 18
= 15

Answer(s): 15