155 students went for a spelling test and 44 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
= 155 - 44
= 111
2 u + 1 p = 44
1 p = 44 - 2 u --- (1)
3 u + 4 p = 111
4 p = 111 - 3 u --- (2)
Make p the same.
(1)
x44 p = 176 - 8 u --- (3)
(2) = (3)
111 - 3 u = 176 - 8 u
8 u - 3 u = 176 - 111
5 u = 65
1 u = 65 ÷ 5 = 13
Number of boys who did not achieve Bronze certificates
= 3 u
= 3 x 13
= 39
Number of girls who did not achieve Bronze certificates
= 111 - 39
= 72
Answer(s): 72
