The average age of 19 students of a class is 22 years. If a new student of age 42 years joins the class, then what will be the average age of these 20 students?

Correct option is D

Given:
Average age of 19 students = 22 years

Formula Used:
New average = (Total sum + New student’s age) ÷ New total number
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Solution:

Total age of 19 students = 19 × 22 = 418 years
Age of new student = 42 years
Total age of 20 students = 418 + 42 = 460 years
New average = 460 ÷ 20 = 23 years