RBI Grade B Officers 21 Nov 2015 Paper

Three years ago, Raj’s age was equal to the sum of the present ages of his only son and only daughter. Three years ago, the respective ratio between the ages of his daughter and his son that time was 12:13. if Raj’s wife is 5 years younger to him and her present age is twice the present age of their daugher, what is the present age of their son? (in years)