In a class, 12 girls jumped an average of 1.28 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.46 m in the same test. The total average of the whole class was 1.34 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
12 |
1 u |
1 u + 12 |
Value |
1.28 |
1.46 |
1.34 |
Total Value |
15.36 |
1.46 u |
1.34 u + 16.08 |
Total number of boys = 1 u
Total number of children = 1 u + 12
Total length that the girls jumped
= 12 x 1.28
= 15.36 m
Total length that the boys jumped
= 1 u x 1.46
= 1.46 u
Total length that the children jumped
= 1.34(1 u + 12)
= 1.34 u + 16.08
15.36 + 1.46 u = 1.34 u + 16.08
1.46 u - 1.34 u = 16.08 - 15.36
0.12 u = 0.72
1 u = 0.72 ÷ 0.12 = 6
Number of boys
= 1 u
= 6
Answer(s): 6