I am Tom Laidlaw, 74, living in Vancouver, WA. Fifty years ago I failed calculus, but I would like to learn some of it. Enough to help me with some math puzzles. My main interest right now is the Goat and Silo problem. If I can find a thread like that on this site, that would be great. I have already seen a simpler proble, so I will start on that site. So Math Puzzles is my main interest.