Mr Ahmad bought some pizzas for a group of students. There was an equal number of girls and boys. The girls received 2 times as many pizzas as the boys. Each boy ate
16 of a pizza and the boys finished all the pizzas given to them. Each girl ate
112 of a pizza and the girls had 9
12 pizzas left. How many pizzas did Mr Ahmad buy?
|
Girls (1) |
Boys (2) |
Before |
2 u |
1 u |
Change |
- 1 p |
- 2 p |
After |
114 |
0 |
16 =
212 Cutting the slices of pizzas into same size. Each pizza was cut into 12 slices. Every girl ate 1 slice of pizza and every boy ate 2 slices of pizza.
Number of slices that the girls had left
= 9
12 ÷
112 =
192 x 12
= 114
2 u - 1 p = 114 --- (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 = 114
4 p - 1 p = 114
3 p = 114
1 p = 114 ÷ 3 = 38
Total number of slices of pizzas for girls
= 114 + 1 p
= 114 + 38
= 152
Total number of slices of pizzas for boys
= 152 ÷ 2
= 76
Total number of slices of pizzas for students
= 152 + 76
= 228
Total number of pizzas that Mr Ahmad bought
= 228 ÷ 12
= 19
Answer(s): 19