Difference in ages: 16 (29 - 13)
When you are the age your father was when you were born, he will be twice your age. Now that he's twice your age,
yours is the difference between the 2 ages, or.
Who writes these problems? Isn't 16 too young to be a father? Isn't a 16 year-old having a kid, a kid having a kid?
Maybe it's because I never did, at that age!