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. Choices: A) 35 B) 38 C) 45 D) 36 E) 60
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:36
<result>D</result>
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.