In a class, 14 girls jumped an average of 1.34 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.56 m in the same test. The total average of the whole class was 1.42 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
14 |
1 u |
1 u + 14 |
Value |
1.34 |
1.56 |
1.42 |
Total Value |
18.76 |
1.56 u |
1.42 u + 19.88 |
Total number of boys = 1 u
Total number of children = 1 u + 14
Total length that the girls jumped
= 14 x 1.34
= 18.76 m
Total length that the boys jumped
= 1 u x 1.56
= 1.56 u
Total length that the children jumped
= 1.42(1 u + 14)
= 1.42 u + 19.88
18.76 + 1.56 u = 1.42 u + 19.88
1.56 u - 1.42 u = 19.88 - 18.76
0.14 u = 1.12
1 u = 1.12 ÷ 0.14 = 8
Number of boys
= 1 u
= 8
Answer(s): 8