In a class, 11 girls jumped an average of 1.32 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 1.37 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
11 |
1 u |
1 u + 11 |
Value |
1.32 |
1.48 |
1.37 |
Total Value |
14.52 |
1.48 u |
1.37 u + 15.07 |
Total number of boys = 1 u
Total number of children = 1 u + 11
Total length that the girls jumped
= 11 x 1.32
= 14.52 m
Total length that the boys jumped
= 1 u x 1.48
= 1.48 u
Total length that the children jumped
= 1.37(1 u + 11)
= 1.37 u + 15.07
14.52 + 1.48 u = 1.37 u + 15.07
1.48 u - 1.37 u = 15.07 - 14.52
0.11 u = 0.55
1 u = 0.55 ÷ 0.11 = 5
Number of boys
= 1 u
= 5
Answer(s): 5