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

Total age of 17 people = 17 x 17 = 289

total age of two new people = 19 x 2 = 38

Total age 19 people = 289 + 38 = 327

Total age 18people after leaving one person = 327 - 25 = 302

New average age of the group = 302 ÷ 18 = 16.78 years