There are 165 children in a parade square.
27 of the boys and
35 of the girls wear glasses, there are 110 children in the parade square who do not wear glasses. How many girls do not wear glasses?
| |
Boys |
Girls |
Total |
| Do not wear glasses |
5 u |
2 p |
110 |
| Wear glasses |
2 u |
3 p |
55 |
| Total |
7 u |
5 p |
165 |
Number of children who wear glasses
= 165 - 110
= 55
5 u + 2 p = 110 --- (1)
2 u + 3 p = 55 --- (2)
Make u the same.
(1)
x 2 10 u + 4 p = 220 --- (3)
(2)
x 5 10 u + 15 p = 275 --- (4)
(4) - (3)
(10 u + 15 p) - (10 u + 4 p) = 275 - 220
15 p - 4 p = 55
11 p = 55
1 p = 55 ÷ 11 = 5
Number of girls who do not wear glasses
= 2 p
= 2 x 5
= 10
Answer(s): 10
