In a class, 8 girls jumped an average of 1.49 m for their standing broad jump in their fitness test. The boys in the same class jumped an average of 1.51 m in the same test. The total average of the whole class was 1.5 m. How many boys were there?
|
Girls |
Boys |
Children |
Number |
8 |
1 u |
1 u + 8 |
Value |
1.49 |
1.51 |
1.5 |
Total Value |
11.92 |
1.51 u |
1.5 u + 12 |
Total number of boys = 1 u
Total number of children = 1 u + 8
Total length that the girls jumped
= 8 x 1.49
= 11.92 m
Total length that the boys jumped
= 1 u x 1.51
= 1.51 u
Total length that the children jumped
= 1.5(1 u + 8)
= 1.5 u + 12
11.92 + 1.51 u = 1.5 u + 12
1.51 u - 1.5 u = 12 - 11.92
0.01 u = 0.08
1 u = 0.08 ÷ 0.01 = 8
Number of boys
= 1 u
= 8
Answer(s): 8