The average age of 30 students is 15 years. If teacher’s age is included, average becomes 16. Find teacher’s age.

A. 45
B. 46
C. 47
D. 48

Solution:
Total age of students = 30×15 = 450
Including teacher = 31×16 = 496
Teacher’s age = 496 – 450 = 46
Answer: B