In a classroom the average age of 39 students was 15 years. If the age of a teacher is added then the average age increased by 3 months. Find age of the teacher.

25 years 26 years 35 years 20 years

25 years

The average age increased = 3 months Total age increased by = 40 × 3 = 120 month = 10 years Teacher age = 15 years + 10 years = 25 years