165 pupils went for a dancing competition and 47 of them achieved Bronze certificates.
25 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 |
| 2 u |
3 u |
1 p |
4 p |
Number of pupils who did not achieve Bronze certificates
= 165 - 47
= 118
2 u + 1 p = 47
1 p = 47 - 2 u --- (1)
3 u + 4 p = 118
4 p = 118 - 3 u --- (2)
Make p the same.
(1)
x44 p = 188 - 8 u --- (3)
(2) = (3)
118 - 3 u = 188 - 8 u
8 u - 3 u = 188 - 118
5 u = 70
1 u = 70 ÷ 5 = 14
Number of girls who did not achieve Bronze certificates
= 3 u
= 3 x 14
= 42
Number of boys who did not achieve Bronze certificates
= 118 - 42
= 76
Answer(s): 76
