The average height of some girls is 134 cm. When 3 boys, with a total height of 360 cm, are included, the average height if the children becomes 127 cm. How many children are there altogether?
|
Girls |
Boys |
Total |
Number |
1 u |
3 |
1 u + 3 |
Value |
134 |
|
127 |
Total value |
134 u |
360 |
127 u + 381 |
Total height of the girls
= 1 u x 134
= 134 u
Total height of the children = 134 u + 360
134 u + 360 = 127 u + 381
134 u - 127 u = 381 - 360
7 u = 21
1 u = 21 ÷ 7 = 3
Total number of children
= 1 u + 3
= 3 + 3
= 6
Answer(s): 6