In a class, 10 girls jumped an average of 1.39 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 1.46 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
10 |
1 u |
1 u + 10 |
Value |
1.39 |
1.6 |
1.46 |
Total Value |
13.9 |
1.6 u |
1.46 u + 14.6 |
Total number of boys = 1 u
Total number of children = 1 u + 10
Total length that the girls jumped
= 10 x 1.39
= 13.9 m
Total length that the boys jumped
= 1 u x 1.6
= 1.6 u
Total length that the children jumped
= 1.46(1 u + 10)
= 1.46 u + 14.6
13.9 + 1.6 u = 1.46 u + 14.6
1.6 u - 1.46 u = 14.6 - 13.9
0.14 u = 0.7
1 u = 0.7 ÷ 0.14 = 5
Number of boys
= 1 u
= 5
Answer(s): 5