135 students went for a singing competition and 42 of them achieved Bronze certificates.
25 of the girls and
15 of the boys achieved Bronze certificates. How many girls did not achieve Bronze certificates?
| Boys |
Girls |
| 5 u |
5 p |
Achieved
Bronze |
Did not achieve
Bronze |
Achieved
Bronze |
Did not achieve
Bronze |
| 2 u |
3 u |
1 p |
4 p |
Number of students who did not achieve Bronze certificates
= 135 - 42
= 93
2 u + 1 p = 42
1 p = 42 - 2 u --- (1)
3 u + 4 p = 93
4 p = 93 - 3 u --- (2)
Make p the same.
(1)
x44 p = 168 - 8 u --- (3)
(2) = (3)
93 - 3 u = 168 - 8 u
8 u - 3 u = 168 - 93
5 u = 75
1 u = 75 ÷ 5 = 15
Number of boys who did not achieve Bronze certificates
= 3 u
= 3 x 15
= 45
Number of girls who did not achieve Bronze certificates
= 93 - 45
= 48
Answer(s): 48
