The average age of 20 students in a class is 15 years. If the age of teacher is also included, the average becomes 16 years, find the age of the teacher.
Pick one
A) 35  B) 38  C) 45  D) 36  E) 60

Rationale: "explanation : if teacher ' s age is 15 years , there is no change in the average . but teacher has contributed 1 year to all the students along with maintaining his age at 16 . age of teacher = average age of all + total increase in age = 16 + ( 1 x 20 ) = 36 years answer : d"
Answer: D