"Julian Havils Impossible? is a superb discussion of problems easily understood by a high schooler, yet with solutions so counterintuitive as to seem impossible. Topics include the notorious Monty Hall three-door problem, the Gamow-Stern elevator paradoxes, the Kruskal count card trick, Cantors 'paradise' of alephs, and the mind-blowing Banach-Tarski paradox, all analyzed in depth by a master who does not hold back equations that provide elegant proofs. There are surprises on almost every page."--Martin Gardner "This book is a fascinating and thoroughly enjoyable read. Havil offers an engaging collection of counterintuitive results and seemingly impossible problems. Some of the material is truly astonishing, and the author conveys his sense of surprise very effectively. Each problem ultimately yields to careful and well-presented analysis. The history of many of the results is discussed, and further references are provided."--Nick Hobson, creator of the award-winning Web site Nicks Mathematical Puzzles "I thought it impossible for Julian Havil to exceed Nonplussed!, his previous collection of perplexing math puzzlers. And yet he has done just that with the sequel Impossible?, an accomplishment that has left me nonplussed."--Paul J. Nahin, author of An Imaginary Tale