Correct option is D
Given:
Average age of 40 students = 15 years.
Average age of 40 students and 1 teacher = 16 years.
Formula Used:
Total sum = Average Number of terms
Solution:
Total age of 40 students ;
= 15 40 = 600 years
Total age of 40 students and 1 teacher ;
= 41 16 = 656 years
Then,
Teacher's age = 656 - 600 = 56 years