In a class, 8 girls jumped an average of 1.26 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.47 m in the same test. The total average of the whole class was 1.41 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
8 |
1 u |
1 u + 8 |
Value |
1.26 |
1.47 |
1.41 |
Total Value |
10.08 |
1.47 u |
1.41 u + 11.28 |
Total number of boys = 1 u
Total number of children = 1 u + 8
Total length that the girls jumped
= 8 x 1.26
= 10.08 m
Total length that the boys jumped
= 1 u x 1.47
= 1.47 u
Total length that the children jumped
= 1.41(1 u + 8)
= 1.41 u + 11.28
10.08 + 1.47 u = 1.41 u + 11.28
1.47 u - 1.41 u = 11.28 - 10.08
0.06 u = 1.2
1 u = 1.2 ÷ 0.06 = 20
Number of boys
= 1 u
= 20
Answer(s): 20