158 students went for a physical fitness test and 71 of them achieved Gold certificates.
35 of the boys and
14 of the girls achieved Gold certificates. How many boys did not achieve Gold certificates?
| Girls |
Boys |
| 5 u |
4 p |
Achieved
Gold |
Did not achieve
Gold |
Achieved
Gold |
Did not achieve
Gold |
| 3 u |
2 u |
1 p |
3 p |
Number of students who did not achieve Gold certificates
= 158 - 71
= 87
3 u + 1 p = 71
1 p = 71 - 3 u --- (1)
2 u + 3 p = 87
3 p = 87 - 2 u --- (2)
Make p the same.
(1)
x33 p = 213 - 9 u --- (3)
(2) = (3)
87 - 2 u = 213 - 9 u
9 u - 2 u = 213 - 87
7 u = 126
1 u = 126 ÷ 7 = 18
Number of girls who achieved Gold certificates
= 3 u
= 3 x 18
= 54
Number of boys who achieved Gold certificates
= 71 - 54
= 17
Answer(s): 17
