Average age of 22 teachers is 64 years. After involving a new teacher in that group the average increases by 1 year. What is the age of the new teacher?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 87 years.
We know that,
Average = Sum of observations/Number of observations
The sum of the age of 22 teachers = 22 × 64 = 1408 years
New average age = 65 years
The sum of the age of 23 teachers = 23 × 65 = 1495 years
Now,
Age of new teacher = 1495 - 1408 = 87 years