190 pupils went for a dancing competition and 56 of them achieved Gold certificates.
25 of the girls and
15 of the boys achieved Gold certificates. How many girls did not achieve Gold certificates?
Boys |
Girls |
5 u |
5 p |
Achieved Gold |
Did not achieve Gold |
Achieved Gold |
Did not achieve Gold |
2 u |
3 u |
1 p |
4 p |
Number of pupils who did not achieve Gold certificates
= 190 - 56
= 134
2 u + 1 p = 56
1 p = 56 - 2 u --- (1)
3 u + 4 p = 134
4 p = 134 - 3 u --- (2)
Make p the same.
(1)
x44 p = 224 - 8 u --- (3)
(2) = (3)
134 - 3 u = 224 - 8 u
8 u - 3 u = 224 - 134
5 u = 90
1 u = 90 ÷ 5 = 18
Number of boys who did not achieve Gold certificates
= 3 u
= 3 x 18
= 54
Number of girls who did not achieve Gold certificates
= 134 - 54
= 80
Answer(s): 80