Correct Answer - Option 4 : 87 years

**Calculation:**

Let be assume present age of A, B, and C is A, B, and C

⇒ (A - 6) = 2 × (B - 4) ---(1)

⇒ C = B + 9 ---(2)

⇒ C = A - 9 ---(3)

⇒ By solving equation (1), (2) and (3)

⇒ A = 38, B = 20, C = 29

⇒ The sum of present age of A, B, and C = A + B + C = 38 + 20 + 29 = 87

**∴ The required result will be 87.**