10. One year ago a father was four times as old as his son. In 6 years time, his age exceeds twice his son�s age by 9 years. Ratio of their ages is:

11. The ages of A and B are in the ratio 2:5. After 8 years their ages will be in the ratio 1:2. The difference of their ages is:

12. The age of a man is 4 times that of his son Five years ago the man was nine times as old as his son was at that time. The present age of the name is: