The average age of 19 students is 17 years. A teacher joins the group, and the average becomes 18 years. What is the teacher's age?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 37.
Total age 19 students = 19 × 17 = 323
New total age (20 persons) = 20 × 18 = 360
Teacher's age = 360 – 323 = 37 years