In a class, 8 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 1.6 m in the same test. The total average of the whole class was 1.56 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
8 |
1 u |
1 u + 8 |
Value |
1.52 |
1.6 |
1.56 |
Total Value |
12.16 |
1.6 u |
1.56 u + 12.48 |
Total number of boys = 1 u
Total number of children = 1 u + 8
Total length that the girls jumped
= 8 x 1.52
= 12.16 m
Total length that the boys jumped
= 1 u x 1.6
= 1.6 u
Total length that the children jumped
= 1.56(1 u + 8)
= 1.56 u + 12.48
12.16 + 1.6 u = 1.56 u + 12.48
1.6 u - 1.56 u = 12.48 - 12.16
0.04 u = 0.32
1 u = 0.32 ÷ 0.04 = 8
Number of boys
= 1 u
= 8
Answer(s): 8