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?

Correct option is B

Given:
Average age of 22 teachers is 64 years. After involving a new teacher in that group the average increases by 1 year Formula Used:
Total Age = (Average Age × Number of people)
Solution:
Total age of 22 teachers = 22 × 64 = 1408 years After including the new teacher, the total age = 23 × 65 = 1495 years Age of the new teacher = 1495 - 1408 = 87 years Therefore, the correct answer is 87 years.
Alternate Solution:
Previous average is a and new number is b and the increased average is n
Then, New age = a + n × b
So the new age will be, 64 + (22 +1) = 87