The difference between the present ages of Arun and Deepak is 14 years. Seven years ago, the ratio of their ages was 5 : 7 respectively. What is Deepak's present age?

At the time of marriage, a man was 6 years older than his wife. 12 years after the marriage, his age became 65 times the age of his wife. What were their ages (in years) at the time of marriage?

The total age of father and son at present is 40 years. After 16 years, the age of the father will be twice the age of his son. What is the present age of the son?