There are 95 students in a hall.
27 of the boys and
35 of the girls wear glasses, there are 60 students in the hall who do not wear glasses. How many girls wear glasses?
| |
Boys |
Girls |
Total |
| Do not wear glasses |
5 u |
2 p |
60 |
| Wear glasses |
2 u |
3 p |
35 |
| Total |
7 u |
5 p |
95 |
Number of students who wear glasses
= 95 - 60
= 35
5 u + 2 p = 60 --- (1)
2 u + 3 p = 35 --- (2)
Make u the same.
(1)
x 2 10 u + 4 p = 120 --- (3)
(2)
x 5 10 u + 15 p = 175 --- (4)
(4) - (3)
(10 u + 15 p) - (10 u + 4 p) = 175 - 120
15 p - 4 p = 55
11 p = 55
1 p = 55 ÷ 11 = 5
Number of girls who wear glasses
= 3 p
= 3 x 5
= 15
Answer(s): 15
