The average age of 30 students in a class is 20 years. If each student's age is increased by 5 years, then determine the number by which the average age is increased.

Correct option is C

Given:
- Average age of 30 students = 20 years
- Increase in each student's age = 5 years
Formula Used:
When all values are increased by a constant, the average increases by the same constant.
Solution:
Since each student's age is increased by 5 years, the average age also increases by 5 years.