In a class, 6 girls jumped an average of 1.25 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.38 m in the same test. The total average of the whole class was 1.32 m. How many boys were there?
| |
Girls |
Boys |
Children |
| Number |
6 |
1 u |
1 u + 6 |
| Value |
1.25 |
1.38 |
1.32 |
| Total Value |
7.5 |
1.38 u |
1.32 u + 7.92 |
Total number of boys = 1 u
Total number of children = 1 u + 6
Total length that the girls jumped
= 6 x 1.25
= 7.5 m
Total length that the boys jumped
= 1 u x 1.38
= 1.38 u
Total length that the children jumped
= 1.32(1 u + 6)
= 1.32 u + 7.92
7.5 + 1.38 u = 1.32 u + 7.92
1.38 u - 1.32 u = 7.92 - 7.5
0.06 u = 0.42
1 u = 0.42 ÷ 0.06 = 7
Number of boys
= 1 u
= 7
Answer(s): 7
