Question

The mean age of a group of persons is 40 , another group has mean age 48, if the ratio of number of persons in two groups is 5:3, find the mean age of all the persons in two groups?

Answer 1

Conditions

The mean age of a group of persons is 40, another group has mean age 48, if the ratio of number of persons in two groups is 5:3, find the mean age of all the persons in two groups?

Solution

As we know from the conditions, the first group of persons has five subgroups, which are have some number of persons, equal to each other, and the second group consists of 3 subgroups with the same number of persons. The mean age in a group is the rate of the sum of all ages of persons in group to the number of persons. That's why in two groups there are eight subgroups and five of them have the mean age 40 and three – 48. That's why the mean age of all the persons in two groups can be found in such way:

$$\frac{40 \cdot 5 + 48 \cdot 3}{8} = \frac{200 + 144}{8} = \frac{344}{8} = 43$$

Answer: 43