Question

In a group of 7 people the average age is found to be 17 years. Two more people joined with an average age 19 years. One person left the group whose age was 25 years. What is the new average age of the group?

Answer 1

Given, average of 7 people=17yrs

so total age of 7 people=17x7=119

2 more people whose average is 19 joined the group so their age=2x19=38

Total age of 9 people=119+38=157.

But 1 man left the group whose age=25

so total of remaining members

=157-25=132

also remaining number of people is

7+2-1=8

Average of remaining 8 persons=132/8=16.5 year.

Answer=16.5