The ratio of the present ages of a son and his father is 1 : 5 and that of his mother and his father is 4 : 5. After 2 years the ratio of the age of the son to his mother will be 3 : 10. Find the present age of father.

35 years

 ATQ,

Mother :   Father   :   Son          

    4      :      5        :     1

Now,

⇒ \(\frac{4R + 2}{1R + 2}\) = \(\frac{10}{3}\)

⇒ 12R + 6 = 10R + 20

⇒ 2R = 14

⇒ 1R = 7

Hence,

Father's Present age = 5R = 5 x 7 = 35 years