GIVEN: Age of Ram is 5 times of the age of his son. 5 years ago, Ram was 9 times as old as his son. CONCEPT: Concept of ages. CALCULATION: Suppose the present ages of Ram and his son are ‘R’ and ‘S’ respectively. We have, R = 5S ---(1) And R – 5 = 9 × (S – 5) ---(2) From equation 1 and 2, R – 5 = 9 × (R/5 – 5) ⇒ R – 5 = 9/5(R – 25) ⇒ 5R – 25 = 9R – 225 ⇒ 4R = 200 ⇒ R = 50 Hence, Present age of Ram = 50 years Short TrickWe can solve it with help of options: Option 3: Age of Ram = 50 years
So, Age of son = 50/5 = 10 years5 years age: Age of Ram and Son will be 45 and 5 years respectively. We can observe that age of son is 9 times the age of Ram. Hence, Option 3 is correct.