The average age of 19 boys in a class is 21 years. If the teacher's age is included, the average increases to 22 years. What is the teacher's age? `A. 39 years` `B. 41 years` `C. 40 years` `D. 44 years`

Options

A. 39 yr
B. 41 yr
C. 40 yr
D. 44 yr

Answer

B

Explanation

The average age of 19 boys `= 21 yr`
when teacher comes in the class, then age becomes 19 boys +1 teacher = 22 yr
Age of teacher = Old average + New average `= 21+ 20 = 41 yr`