The average age of 48 students of a class is 10 years. If the age of the teacher is also included, the average age of the whole group becomes 11 years. The age (in years) of the teacher is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 59.
Average age of 48 students = 10 years
Including teacher, total people = 49
New average = 11 years
Total age of 48 students = 48 × 10 = 480
Total age of 49 people = 49 × 11 = 539
Teacher's age = 539 - 480 = 59 years