If the ages of 3 persons are 17, 16, and 12, and another person is added making the average age 20, what is the age of the new person?

If the ages of 3 persons are 17, 16, and 12, and another person is added making the average age 20, what is the age of the new person?

Explanation

Total of 3 ages = 17 + 16 + 12 = 45

New average = 20, for 4 people → Total = 20 × 4 = 80

Age of 4th person = 80 − 45 = 35