Book excerpt: You don't need to be a genius or a professor of mathematics to have hours of fun with this book - just some logical thinking, a little common sense, a bit of general knowledge and the stubbom determination not to be beaten! Pit your wits against Mensa's masterminds with this huge collection of brain teasers. This book contains more than 500 puzzles and tests of all kinds to delight and bamboozle every type of puzzler.