Kartik’s father age is four times the age of Kartik. Three years ago, Kartik’s father age was seven times the age of Kartik. The present age of Kartik is:

Let the age of Karthik = p                            

                                Karthik's Father               Karthik

Present Age                       4p                              p

Three years ago              4p-3                           p-3 

Given, Three years Karthik's Father age was seven times the age of Karthik

$$=$$>               4p-3 = 7(p-3)

                     4p-3 = 7p-21

                        3p = 18

                          p = 6