(Disclaimer: I remember a puzzle like this I did a long time ago, but this isn't a direct copy of the puzzle, only it's formatting. If this is appears to be a copy of another riddle, I will simply say that this mimics only the format, while not the actual puzzle. Please enjoy.)
Jim and John are brothers. One day, they go to the local drugstore to pick up some medicine for their sick father (their mother being at work). When they arrive, they pick the proper medicine and place it, along with $5, on the counter. The clerk, who sees these two young boys unattended in a drugstore, immediately gets suspicious and asks for their age. Jim and John, after huddling for a moment, respond with the following:
John: Well, sir, I'm one-seventh my age older than my brother.
Jim: And twice my age is five-sixths my age more than my brother's.
John: But there is no more than 4 years between us.
Jim: And we aren't quite mature in-law's, yet.
The clerk was befuddled, and distracted enough for the boys to snatch the medicine up and run out with it. After a moment, the clerk recovers and chuckles to himself, having decided that boys these days are very clever.
How old are Jim and John?