Mr Zeph bought some pizzas for a group of pupils. 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
112 of a pizza and the boys had 5
12 pizzas left. How many pizzas did Mr Zeph buy?
|
Boys (1) |
Girls (2) |
Before |
2 u |
1 u |
Change |
- 1 p |
- 2 p |
After |
66 |
0 |
16 =
212 Cutting the slices of pizzas into same size. Each pizza was cut into 12 slices. Every boy ate 1 slice of pizza and every girl ate 2 slices of pizza.
Number of slices that the boys had left
= 5
12 ÷
112 =
112 x 12
= 66
2 u - 1 p = 66 --- (1)
1 u - 2 p = 0
1 u = 2 p --- (2)
Make u the same.
(2)
x22 u = 4 p --- (3)
Substitute (3) into (1).
2 u - 1 p = 66
4 p - 1 p = 66
3 p = 66
1 p = 66 ÷ 3 = 22
Total number of slices of pizzas for boys
= 66 + 1 p
= 66 + 22
= 88
Total number of slices of pizzas for girls
= 88 ÷ 2
= 44
Total number of slices of pizzas for pupils
= 88 + 44
= 132
Total number of pizzas that Mr Zeph bought
= 132 ÷ 12
= 11
Answer(s): 11