4 years ago ratio of the ages of father and son is 8 : 5 . After 2 years the ratio of their ages will become 19 : 13. What is the present age of father ( in years ) ?

36

4 years ago           Father   :     Son

                                8      :     5

Present age of father = 8x + 4    ,     Present age of son = 5x + 4

Ages after 2 years,

Age of father = 8x + 6       &     age of  Son = 5x + 6

Now, \(\frac{8x\; + \;6}{5x \;+\; 6}\) =\(\frac{19}{13}\)

104x  +78  = 95x + 114

9x = 114 -78 =36 

   x=4

Present age of father = 8 × 4 +  4 =36 years