There are 183 children in a basketball court.
38 of the boys and
47 of the girls wear glasses, there are 102 children in the basketball court who do not wear glasses. How many girls do not wear glasses?
| |
Boys |
Girls |
Total |
| Do not wear glasses |
5 u |
3 p |
102 |
| Wear glasses |
3 u |
4 p |
81 |
| Total |
8 u |
7 p |
183 |
Number of children who wear glasses
= 183 - 102
= 81
5 u + 3 p = 102 --- (1)
3 u + 4 p = 81 --- (2)
Make u the same.
(1)
x 3 15 u + 9 p = 306 --- (3)
(2)
x 5 15 u + 20 p = 405 --- (4)
(4) - (3)
(15 u + 20 p) - (15 u + 9 p) = 405 - 306
20 p - 9 p = 99
11 p = 99
1 p = 99 ÷ 11 = 9
Number of girls who do not wear glasses
= 3 p
= 3 x 9
= 27
Answer(s): 27
