140 pupils went for a singing competition and 62 of them achieved Bronze certificates.
35 of the boys and
15 of the girls achieved Bronze certificates. How many boys did not achieve Bronze certificates?
| Girls |
Boys |
| 5 u |
5 p |
Achieved
Bronze |
Did not achieve
Bronze |
Achieved
Bronze |
Did not achieve
Bronze |
| 3 u |
2 u |
1 p |
4 p |
Number of pupils who did not achieve Bronze certificates
= 140 - 62
= 78
3 u + 1 p = 62
1 p = 62 - 3 u --- (1)
2 u + 4 p = 78
4 p = 78 - 2 u --- (2)
Make p the same.
(1)
x44 p = 248 - 12 u --- (3)
(2) = (3)
78 - 2 u = 248 - 12 u
12 u - 2 u = 248 - 78
10 u = 170
1 u = 170 ÷ 10 = 17
Number of girls who did not achieve Bronze certificates
= 2 u
= 2 x 17
= 34
Number of boys who did not achieve Bronze certificates
= 78 - 34
= 44
Answer(s): 44
