In a class, 8 girls jumped an average of 1.48 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.75 m in the same test. The total average of the whole class was 1.63 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
8 |
1 u |
1 u + 8 |
Value |
1.48 |
1.75 |
1.63 |
Total Value |
11.84 |
1.75 u |
1.63 u + 13.04 |
Total number of boys = 1 u
Total number of children = 1 u + 8
Total length that the girls jumped
= 8 x 1.48
= 11.84 m
Total length that the boys jumped
= 1 u x 1.75
= 1.75 u
Total length that the children jumped
= 1.63(1 u + 8)
= 1.63 u + 13.04
11.84 + 1.75 u = 1.63 u + 13.04
1.75 u - 1.63 u = 13.04 - 11.84
0.12 u = 1.2
1 u = 1.2 ÷ 0.12 = 10
Number of boys
= 1 u
= 10
Answer(s): 10