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

Answer:

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

Step-by-step 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

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

$=\frac{142}{20}$

$=7.1\text{ years}$

Answer 2

So if there are twenty children and 6 have an average age of five, you could say their total age together is 30 years. The others (20-6) have an age of 8.

30+ (20-6)*8 = total age of every child at the library. From there divide by the number of children.