The average age of A, B and C is 20 years, and that of B and C is 25 years. What is the age of A?

25 years 10 years 15 years 20 years

10 years

Sum of ages of A, B and C = 20 x 3 = 60 Sum of ages of B and C = 25 x 2 = 50 Age of A = 60 - 50 = 10 years