There are 117 pupils in a tuckshop.
27 of the boys and
35 of the girls wear scarves, there are 71 pupils in the tuckshop who do not wear scarves. How many girls wear scarves?
| |
Boys |
Girls |
Total |
| Do not wear scarves |
5 u |
2 p |
71 |
| Wear scarves |
2 u |
3 p |
46 |
| Total |
7 u |
5 p |
117 |
Number of pupils who wear scarves
= 117 - 71
= 46
5 u + 2 p = 71 --- (1)
2 u + 3 p = 46 --- (2)
Make u the same.
(1)
x 2 10 u + 4 p = 142 --- (3)
(2)
x 5 10 u + 15 p = 230 --- (4)
(4) - (3)
(10 u + 15 p) - (10 u + 4 p) = 230 - 142
15 p - 4 p = 88
11 p = 88
1 p = 88 ÷ 11 = 8
Number of girls who wear scarves
= 3 p
= 3 x 8
= 24
Answer(s): 24
