The average age of A and B is 15 years. If A is to be replaced by C, the average would be 14 years. The average age of C and A is 16 years. Find the age of A.
A + B = 2 × 15 = 30 yr B + C = 2 × 14 = 28 yr C + A = 2 × 16 = 32 yr On adding all three, 2 (A + B + C) = 30 + 28 + 32 = 90 ⇒ A + B + C = 45 ∴ A = (A + B + C) – (B + C) = 45 – 28 = 17 yr
