The difference between the present ages of Arun and Barun is 14 years. 7 years ago the ratio of their ages was 5 : 7 respectively. The present age of Barun is :

Let the present ages of Arun and Barun are x and x +14 years respectively; then
According to question, 7 years ago the ratio of their ages was 5 : 7
(x - 7)/(x + 14 - 7) = 5/7
⇒ (x - 7)7 = 5(x+14 - 7)
⇒ 7x - 49 = 5x + 35
⇒ 2x = 84
∴ x = 42
Hence, age of Barun = 42 + 14 = 56 years