121 students went for a dancing competition and 63 of them achieved Bronze certificates.
35 of the boys and
13 of the girls achieved Bronze certificates. How many boys did not achieve Bronze certificates?
| Girls |
Boys |
| 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
= 121 - 63
= 58
3 u + 1 p = 63
1 p = 63 - 3 u --- (1)
2 u + 2 p = 58
2 p = 58 - 2 u --- (2)
Make p the same.
(1)
x22 p = 126 - 6 u --- (3)
(2) = (3)
58 - 2 u = 126 - 6 u
6 u - 2 u = 126 - 58
4 u = 68
1 u = 68 ÷ 4 = 17
Number of girls who achieved Bronze certificates
= 3 u
= 3 x 17
= 51
Number of boys who achieved Bronze certificates
= 63 - 51
= 12
Answer(s): 12
