山姆·洛伊德的數學謎題

I bought this hoping for a few good brain teasers and ended up spending a whole weekend on it. The selection from the old Cyclopedia is full of genuinely weird, tricky little problems that don't feel like the recycled stuff you see everywhere now. My only warning is that once you start one, it's har

The 14–15 puzzle is as tricky as advertised, though I wish the book included more solutions. Still, the sheer variety of these old puzzles keeps me hooked.