Question

There are 20 children at a library. six of the children have an average age of 5 years. the remaining children have an average age of 8 years. what is the average age of the children at the library?

Answer 1

The average age of the children at the library is 7.1 years.

Explanation:

Given,

Out of 20 children, six of the children have an average age of 5 years,

Thus, the sum of the ages of 6 students = 5 × 6 = 30

( Total sum of observations = Their Average × Total numbers of the observations )

Now, remaining students = 20 - 6 = 14,

Since, the remaining children have an average age of 8 years.

Thus, the sum of the ages of 14 students = 14 × 8 = 112,

Total sum of the ages of 20 students = 30 + 112 = 142

`\text{The average of 20 students}=\frac{\text{Total sum of the ages of 20 students}}{20}`

`=(142)/(20)`

`=7.1\text{ years}`