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? Enter your answer in the box. WILL GIVE BARINLIYEST

Answer 1

Answer: The average age is 7.1 years.

This problem is an example of when we need to take a weighted average. We simply can't just find the average of 5 and 8, because there are different children of each each.

To start, lets multiply the total number of children by their individual ages.

6 x 5 = 30 years
14 x 8 = 112 years

There are 142 years among the 20 years, so divide 142 by 20. This gives us an average age of 7.1 years.