This book has a very simple structure. It begins with a brief section called “Preliminaries” presenting the modicum of back­ ground information needed to solve the 89 problems stated in the next section, called “Sample Problems.” These problems are, for the most part, equipped with hints or answers or both. But thenub of thebook is the section called “Detailed Solutions,” where you will find all 89 sample problems worked out in full detail. In our opinion, just studying these solutions (after first spending a decent amount of time trying to solve the problems on your own!) is a perfectly plausible way of learning about sequences and combinatorial problems. Finally, to make sure you have mastered the subject matter of the book, you should attack all 37 problems in the section called “Test Problems.” In fact, think of this section as a (rather tough) final examination on which you must get at least a passing grade. Good luck!