The average age of Rustam and Preetam is 30 years. The average age of Preetam and Geetam is 20 years. The average age of Rustam and Geetam is 26 years. What will be the age of the youngest of the three after 5 years?

21 years

ATQ,

Sum of Rustam's and Preetam's age = 60  ....(1)

Sum of Preetam's and Geetam's age = 40  ....(2)

Sum of Rustam's and Geetam's age = 52   .....(3)

From equations (1), (2) & (3)

Rustam's age = 36

Preetam's age = 24

Geetam's age = 16

Age of youngest one after 5 years = 16 + 5 = 21 years