Let Dilip's present age be "a" and, Sumit's present age be "b" So according to Question, a - 5 = 4(b - 5) ⇒ a + 15 = 4b ----(1) Similarly, a + 5 = 3(y + 5) ⇒ a - 10 = 3b ----(2) Solving (1) and (2) simultaneously b = 25 ∴ Sumit's present age is 25 years.