The ages of Samir and Saurabh are in the ratio of 8 : 15 respectively . After 9 years the ratio of their ages will be 11 : 18. What is the difference between their ages in years?

Let the present ages of Samir and Saurabh are 8a and 15a years respectively ; . After 9 years the ages of Samir and Saurabh will be 8a + 9 and 15a + 9. According to question, After 9 years the ratio of their ages will be 11 : 18, then (8a + 9)/ = 11/18 ⇒ (8x + 9) x 18 = 11 x (15a + 9) ⇒ 144a + 162 = 165a + 99 ⇒ 21a = 63 ∴ a = 3 Hence, difference of their ages = 15a - 8a = 7a = 7 x 3 = 21 years