<P>Which US president did Washington Irving once unflatteringly refer to as a “withered little apple-john?” What reduplicative word refers to a Siamese three-wheeled taxi? In which city is Charlemagne's octagon? These and other fiendishly difficult questions have stumped pupils at King William's College as part of its annual General Knowledge Papers for more than a century—along with <I>Guardian </I>readers, for whom the test has been reprinted in its entirety since 1951.</P> <div>Here, for the first time, is a compendium of the wonderfully obscure questions—and their often unexpected answers—that have appeared on the test over the past thirty years. Guaranteed to challenge even the most ardent trivia enthusiast, this exhaustive compilation is organized thematically and chronologically and includes a set of previously unpublished questions by current quizmaster Pat Cullen.</DIV> <div> </DIV> <div>For history hotshots, fountains of fact, and perennial powerhouses of pub trivia, <I>The World's Most Difficult Quiz </I>lives every bit up to its superlative name, offering an addictive assortment of intriguing questions.</DIV> <p> </P>