Mr Michael 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
12 of a pizza and the girls finished all the pizzas given to them. Each boy ate
16 of a pizza and the boys had 11
23 pizzas left. How many pizzas did Mr Michael buy?
|
Boys (1) |
Girls (2) |
Before |
2 u |
1 u |
Change |
- 1 p |
- 3 p |
After |
70 |
0 |
12 =
36 Cutting the slices of pizzas into same size. Each pizza was cut into 6 slices. Every boy ate 1 slice of pizza and every girl ate 3 slices of pizza.
Number of slices that the boys had left
= 11
23 ÷
16 =
353 x 6
= 70
2 u - 1 p = 70 --- (1)
1 u - 3 p = 0
1 u = 3 p --- (2)
Make u the same.
(2)
x22 u = 6 p --- (3)
Substitute (3) into (1).
2 u - 1 p = 70
6 p - 1 p = 70
5 p = 70
1 p = 70 ÷ 5 = 14
Total number of slices of pizzas for boys
= 70 + 1 p
= 70 + 14
= 84
Total number of slices of pizzas for girls
= 84 ÷ 2
= 42
Total number of slices of pizzas for pupils
= 84 + 42
= 126
Total number of pizzas that Mr Michael bought
= 126 ÷ 6
= 21
Answer(s): 21