The average age of a group of 10 persons was decreased by 3 years when one person, whose age was 42 years, was replaced by a new person. Find the age of the new person?
Q1. The average age of a group of 10 persons was decreased by 3 years when one person, whose age was 42 years, was replaced by a new person. Find the age of the new person?
Answer: 12 years
Explanation: The total age drops by 3 × 10 = 30 years when one person is replaced; new person's age = 42 − 30 = 12 years.