126 pupils went for a dancing competition and 66 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 pupils who did not achieve Bronze certificates
= 126 - 66
= 60
3 u + 1 p = 66
1 p = 66 - 3 u --- (1)
2 u + 2 p = 60
2 p = 60 - 2 u --- (2)
Make p the same.
(1)
x22 p = 132 - 6 u --- (3)
(2) = (3)
60 - 2 u = 132 - 6 u
6 u - 2 u = 132 - 60
4 u = 72
1 u = 72 ÷ 4 = 18
Number of boys who did not achieve Bronze certificates
= 2 u
= 2 x 18
= 36
Number of girls who did not achieve Bronze certificates
= 60 - 36
= 24
Answer(s): 24
