Puzzle fans have bought more than 650,000 copies of the Mensa Genius Quiz series,the only books that let readers match wits with Mensa," comparing how well they do against members of the famous high-IQ society. Here, in a giant omnibus edition, are four best-selling titles: The Mensa Genius Quiz Books 1 & 2 , The Mensa Genius Quiz-A-Day Book , and The Mensa Genius ABC Book . Here are more than 800 fun mindbenders to exercise every part of your brain,word games, trivia, logic riddles, number challenges, visual puzzles,plus tips on how to improve your thinking skills. All the puzzles have been tested by members of American Mensa, Ltd., and include the percentage of Mensa testers who could solve each one, so that you can score yourself against some of the nation's fittest mental athletes.