106 students went for a physical fitness test and 54 of them achieved Bronze certificates.
35 of the girls and
13 of the boys achieved Bronze certificates. How many girls did not achieve Bronze certificates?
| Boys |
Girls |
| 5 u |
3 p |
Achieved
Bronze |
Did not achieve
Bronze |
Achieved
Bronze |
Did not achieve
Bronze |
| 3 u |
2 u |
1 p |
2 p |
Number of students who did not achieve Bronze certificates
= 106 - 54
= 52
3 u + 1 p = 54
1 p = 54 - 3 u --- (1)
2 u + 2 p = 52
2 p = 52 - 2 u --- (2)
Make p the same.
(1)
x22 p = 108 - 6 u --- (3)
(2) = (3)
52 - 2 u = 108 - 6 u
6 u - 2 u = 108 - 52
4 u = 56
1 u = 56 ÷ 4 = 14
Number of boys who achieved Bronze certificates
= 3 u
= 3 x 14
= 42
Number of girls who achieved Bronze certificates
= 54 - 42
= 12
Answer(s): 12
