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, then mean age of all the persons in two group is

Answer 1

hi frankly I don't know the answer.

Answer 2

Mean age of all the persons in two group is 43

1)  The ratio of persons in two groups is 5:3

Let the number of peoples be 5x and 3x in the two groups respectively.

2) Average age of first group = 40.

Number of people is 5x

Sum of ages of people of first group is = 40*5x = 200x

3) Average age of first group = 48.

Number of people is 3x

Sum of ages of people of first group is = 48*3x = 144x

4) Total sum of ages of people would be 200x + 144x  = 344x

Total sum of number of peoples would be 5x+3x = 8x

5) Total average of ages of people of both groups would be 344x/8x = 43