In a class, 12 girls jumped an average of 1.27 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.41 m in the same test. The total average of the whole class was 1.35 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
12 |
1 u |
1 u + 12 |
Value |
1.27 |
1.41 |
1.35 |
Total Value |
15.24 |
1.41 u |
1.35 u + 16.2 |
Total number of boys = 1 u
Total number of children = 1 u + 12
Total length that the girls jumped
= 12 x 1.27
= 15.24 m
Total length that the boys jumped
= 1 u x 1.41
= 1.41 u
Total length that the children jumped
= 1.35(1 u + 12)
= 1.35 u + 16.2
15.24 + 1.41 u = 1.35 u + 16.2
1.41 u - 1.35 u = 16.2 - 15.24
0.06 u = 0.96
1 u = 0.96 ÷ 0.06 = 16
Number of boys
= 1 u
= 16
Answer(s): 16