Question

The avg age of a grp of friends is 34 yrs. if 5 new friends with an avg age of 30 yrs join the grp, the avg age of the entire grp becomes 32 yrs. how many people were there in the grp initially

Answer 1

Let there be n no. of people

34 x n + 5 x 30 = (n+5) x 32

n = 5

Answer 2

let the original no. of people be x
therefore, as avg. age = total age/no. of people:
34x + 30×5 = (x + 5)32
34x + 150 = 32x + 160
34x - 32x = 160 - 150
2x = 10
x = 5
therefore there were originally 5 people