There are 178 children in a canteen.
27 of the girls and
35 of the boys wear caps, there are 113 children in the canteen who do not wear caps. How many boys wear caps?
| |
Girls |
Boys |
Total |
| Do not wear caps |
5 u |
2 p |
113 |
| Wear caps |
2 u |
3 p |
65 |
| Total |
7 u |
5 p |
178 |
Number of children who wear caps
= 178 - 113
= 65
5 u + 2 p = 113 --- (1)
2 u + 3 p = 65 --- (2)
Make u the same.
(1)
x 2 10 u + 4 p = 226 --- (3)
(2)
x 5 10 u + 15 p = 325 --- (4)
(4) - (3)
(10 u + 15 p) - (10 u + 4 p) = 325 - 226
15 p - 4 p = 99
11 p = 99
1 p = 99 ÷ 11 = 9
Number of boys who wear caps
= 3 p
= 3 x 9
= 27
Answer(s): 27
