Average age = Total age ∕ Number of members Calculation: Total age of 54 students =54×37 Total age of 54 students = 1998 Total age of 55 members (including teacher) =55×38 Total age of 55 members = 2090 Age of the teacher = Total age of 55 members - Total age of 54 students Age of the teacher = 2090-1998 Age of the teacher =92