There are 194 pupils in a basketball court.
38 of the boys and
47 of the girls wear spectacles, there are 113 pupils in the basketball court who do not wear spectacles. How many girls wear spectacles?
| |
Boys |
Girls |
Total |
| Do not wear spectacles |
5 u |
3 p |
113 |
| Wear spectacles |
3 u |
4 p |
81 |
| Total |
8 u |
7 p |
194 |
Number of pupils who wear spectacles
= 194 - 113
= 81
5 u + 3 p = 113 --- (1)
3 u + 4 p = 81 --- (2)
Make u the same.
(1)
x 3 15 u + 9 p = 339 --- (3)
(2)
x 5 15 u + 20 p = 405 --- (4)
(4) - (3)
(15 u + 20 p) - (15 u + 9 p) = 405 - 339
20 p - 9 p = 66
11 p = 66
1 p = 66 ÷ 11 = 6
Number of girls who wear spectacles
= 4 p
= 4 x 6
= 24
Answer(s): 24
