In a class, 6 girls jumped an average of 1.37 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.63 m in the same test. The total average of the whole class was 1.51 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
6 |
1 u |
1 u + 6 |
Value |
1.37 |
1.63 |
1.51 |
Total Value |
8.22 |
1.63 u |
1.51 u + 9.06 |
Total number of boys = 1 u
Total number of children = 1 u + 6
Total length that the girls jumped
= 6 x 1.37
= 8.22 m
Total length that the boys jumped
= 1 u x 1.63
= 1.63 u
Total length that the children jumped
= 1.51(1 u + 6)
= 1.51 u + 9.06
8.22 + 1.63 u = 1.51 u + 9.06
1.63 u - 1.51 u = 9.06 - 8.22
0.12 u = 0.84
1 u = 0.84 ÷ 0.12 = 7
Number of boys
= 1 u
= 7
Answer(s): 7