In a class, 6 girls jumped an average of 1.49 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.58 m in the same test. The total average of the whole class was 1.55 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
6 |
1 u |
1 u + 6 |
Value |
1.49 |
1.58 |
1.55 |
Total Value |
8.94 |
1.58 u |
1.55 u + 9.3 |
Total number of boys = 1 u
Total number of children = 1 u + 6
Total length that the girls jumped
= 6 x 1.49
= 8.94 m
Total length that the boys jumped
= 1 u x 1.58
= 1.58 u
Total length that the children jumped
= 1.55(1 u + 6)
= 1.55 u + 9.3
8.94 + 1.58 u = 1.55 u + 9.3
1.58 u - 1.55 u = 9.3 - 8.94
0.03 u = 0.36
1 u = 0.36 ÷ 0.03 = 12
Number of boys
= 1 u
= 12
Answer(s): 12