In a class, 8 girls jumped an average of 1.44 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.53 m in the same test. The total average of the whole class was 1.47 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
8 |
1 u |
1 u + 8 |
Value |
1.44 |
1.53 |
1.47 |
Total Value |
11.52 |
1.53 u |
1.47 u + 11.76 |
Total number of boys = 1 u
Total number of children = 1 u + 8
Total length that the girls jumped
= 8 x 1.44
= 11.52 m
Total length that the boys jumped
= 1 u x 1.53
= 1.53 u
Total length that the children jumped
= 1.47(1 u + 8)
= 1.47 u + 11.76
11.52 + 1.53 u = 1.47 u + 11.76
1.53 u - 1.47 u = 11.76 - 11.52
0.06 u = 0.24
1 u = 0.24 ÷ 0.06 = 4
Number of boys
= 1 u
= 4
Answer(s): 4