152 pupils went for a spelling test and 50 of them achieved Bronze certificates.
25 of the girls and
14 of the boys achieved Bronze certificates. How many girls did not achieve Bronze certificates?
| Boys |
Girls |
| 5 u |
4 p |
Achieved
Bronze |
Did not achieve
Bronze |
Achieved
Bronze |
Did not achieve
Bronze |
| 2 u |
3 u |
1 p |
3 p |
Number of pupils who did not achieve Bronze certificates
= 152 - 50
= 102
2 u + 1 p = 50
1 p = 50 - 2 u --- (1)
3 u + 3 p = 102
3 p = 102 - 3 u --- (2)
Make p the same.
(1)
x33 p = 150 - 6 u --- (3)
(2) = (3)
102 - 3 u = 150 - 6 u
6 u - 3 u = 150 - 102
3 u = 48
1 u = 48 ÷ 3 = 16
Number of boys who did not achieve Bronze certificates
= 3 u
= 3 x 16
= 48
Number of girls who did not achieve Bronze certificates
= 102 - 48
= 54
Answer(s): 54
