Only the usual highschool math courses are required according to the jacket copy. It's this plus a passion for logic (that's the Otherwise of the subtitle) plus an agile mind which refuses to let go once teased into coming to grips with a tantalizing puzzle. Mr. Barr wrote the outstanding Experiments in TopoLogy (1964, p. 120, J-48). As a personal book this title provides dip-in-and-out pleasure or the sort of mind stretcher to hand over to the bed bound student. (The puzzles are not easy. Their solutions absorb attention and make time race.) Math teachers looking for the stumper of the week will find this a valuable source of new ideas. The presentation of problems is so casual that math students inured to the stultifying prose of text book problem presentation will be pleasantly attracted.