In a class, 10 girls jumped an average of 1.26 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.48 m in the same test. The total average of the whole class was 1.38 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
10 |
1 u |
1 u + 10 |
Value |
1.26 |
1.48 |
1.38 |
Total Value |
12.6 |
1.48 u |
1.38 u + 13.8 |
Total number of boys = 1 u
Total number of children = 1 u + 10
Total length that the girls jumped
= 10 x 1.26
= 12.6 m
Total length that the boys jumped
= 1 u x 1.48
= 1.48 u
Total length that the children jumped
= 1.38(1 u + 10)
= 1.38 u + 13.8
12.6 + 1.48 u = 1.38 u + 13.8
1.48 u - 1.38 u = 13.8 - 12.6
0.1 u = 1.2
1 u = 1.2 ÷ 0.1 = 12
Number of boys
= 1 u
= 12
Answer(s): 12