150 pupils went for a spelling test and 44 of them achieved Silver certificates.
25 of the boys and
15 of the girls achieved Silver certificates. How many boys did not achieve Silver certificates?
| Girls |
Boys |
| 5 u |
5 p |
Achieved
Silver |
Did not achieve
Silver |
Achieved
Silver |
Did not achieve
Silver |
| 2 u |
3 u |
1 p |
4 p |
Number of pupils who did not achieve Silver certificates
= 150 - 44
= 106
2 u + 1 p = 44
1 p = 44 - 2 u --- (1)
3 u + 4 p = 106
4 p = 106 - 3 u --- (2)
Make p the same.
(1)
x44 p = 176 - 8 u --- (3)
(2) = (3)
106 - 3 u = 176 - 8 u
8 u - 3 u = 176 - 106
5 u = 70
1 u = 70 ÷ 5 = 14
Number of girls who did not achieve Silver certificates
= 3 u
= 3 x 14
= 42
Number of boys who did not achieve Silver certificates
= 106 - 42
= 64
Answer(s): 64
