In a class, 6 girls jumped an average of 1.52 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.8 m in the same test. The total average of the whole class was 1.66 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
6 |
1 u |
1 u + 6 |
Value |
1.52 |
1.8 |
1.66 |
Total Value |
9.12 |
1.8 u |
1.66 u + 9.96 |
Total number of boys = 1 u
Total number of children = 1 u + 6
Total length that the girls jumped
= 6 x 1.52
= 9.12 m
Total length that the boys jumped
= 1 u x 1.8
= 1.8 u
Total length that the children jumped
= 1.66(1 u + 6)
= 1.66 u + 9.96
9.12 + 1.8 u = 1.66 u + 9.96
1.8 u - 1.66 u = 9.96 - 9.12
0.14 u = 0.84
1 u = 0.84 ÷ 0.14 = 6
Number of boys
= 1 u
= 6
Answer(s): 6