Three years ago, the ratio of the age of father to that of his son was 8 : 3. After 4 years, their ages will be the ratio 11 : 5. What is the present age (in years) of the father ?

51

ATQ,

 Lets assume, 3 years ago father's age is 8x and son's age is 3x

Given after 4 years ratio of their ages ⇒ \(\frac{8x + 3 + 4}{3x + 3 + 4}\) = \(\frac{11}{5}\)

                                                       ⇒ 40x + 35 = 33x + 77

                                                       ⇒ x = 6

Father's present age = 51 years