In a class, 8 girls jumped an average of 1.54 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.79 m in the same test. The total average of the whole class was 1.69 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
8 |
1 u |
1 u + 8 |
Value |
1.54 |
1.79 |
1.69 |
Total Value |
12.32 |
1.79 u |
1.69 u + 13.52 |
Total number of boys = 1 u
Total number of children = 1 u + 8
Total length that the girls jumped
= 8 x 1.54
= 12.32 m
Total length that the boys jumped
= 1 u x 1.79
= 1.79 u
Total length that the children jumped
= 1.69(1 u + 8)
= 1.69 u + 13.52
12.32 + 1.79 u = 1.69 u + 13.52
1.79 u - 1.69 u = 13.52 - 12.32
0.1 u = 1.2
1 u = 1.2 ÷ 0.1 = 12
Number of boys
= 1 u
= 12
Answer(s): 12