Mr Jeremy bought some pizzas for a group of pupils. There was an equal number of girls and boys. The girls received 2 times as many pizzas as the boys. Each boy ate
13 of a pizza and the boys finished all the pizzas given to them. Each girl ate
19 of a pizza and the girls had 12
29 pizzas left. How many pizzas did Mr Jeremy buy?
|
Girls (1) |
Boys (2) |
Before |
2 u |
1 u |
Change |
- 1 p |
- 3 p |
After |
110 |
0 |
13 =
39 Cutting the slices of pizzas into same size. Each pizza was cut into 9 slices. Every girl ate 1 slice of pizza and every boy ate 3 slices of pizza.
Number of slices that the girls had left
= 12
29 ÷
19 =
1109 x 9
= 110
2 u - 1 p = 110 --- (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 = 110
6 p - 1 p = 110
5 p = 110
1 p = 110 ÷ 5 = 22
Total number of slices of pizzas for girls
= 110 + 1 p
= 110 + 22
= 132
Total number of slices of pizzas for boys
= 132 ÷ 2
= 66
Total number of slices of pizzas for pupils
= 132 + 66
= 198
Total number of pizzas that Mr Jeremy bought
= 198 ÷ 9
= 22
Answer(s): 22