The average age of 4 persons A, B, C, and D is 25 years. The ages of A, B, and C are 20 years, 24 years, and 26 years respectively. Find the age of D (in years).

Explanation

​ www.freshersnow.com Information Given: Average age of A, B, C, D = 25 years Number of persons = 4 Ages of A, B, C = 20, 24, 26 years Concept/Formula Used: Average = Total Sum / Number of persons Total Sum = Average × Number of persons Explanation: Total age of all 4 persons = 25 × 4 = 100 Sum of ages of A, B, C = 20 + 24 + 26 = 70 Age of D = Total age − Sum of A, B, C Age of D = 100 − 70 = 30 Hall Approach