I am taking my GED and I'm having trouble with word problems off all sorts. The teacher I have does not explain very well. If anyone can help, I would greatly appreciate it.

For example here is one:

George is 5 times as old as his son. In 15 years he will only be twice as old as his son. How old will his son be in 15 years?

Thank you for taking the time to read and possibly respond.

Have a great day.