124 students went for a spelling test and 60 of them achieved Gold certificates.
35 of the boys and
13 of the girls achieved Gold certificates. How many boys did not achieve Gold certificates?
Girls |
Boys |
5 u |
3 p |
Achieved Gold |
Did not achieve Gold |
Achieved Gold |
Did not achieve Gold |
3 u |
2 u |
1 p |
2 p |
Number of students who did not achieve Gold certificates
= 124 - 60
= 64
3 u + 1 p = 60
1 p = 60 - 3 u --- (1)
2 u + 2 p = 64
2 p = 64 - 2 u --- (2)
Make p the same.
(1)
x22 p = 120 - 6 u --- (3)
(2) = (3)
64 - 2 u = 120 - 6 u
6 u - 2 u = 120 - 64
4 u = 56
1 u = 56 ÷ 4 = 14
Number of girls who achieved Gold certificates
= 3 u
= 3 x 14
= 42
Number of boys who achieved Gold certificates
= 60 - 42
= 18
Answer(s): 18