Organized into five levels of difficulty, Brain Games(R) Sudoku Puzzles is perfect for both seasoned puzzlers and new enthusiasts alike. * Find 162 engaging puzzles in this classic collection that range from easy to expert. * If you get stuck or need a hint, no need to worry: an answer key is found in the back of the book. * 192 pages, spiral bound. Sudoku puzzles are not only fun and addictive, they also work to maintain good mental fitness, building logic and boosting problem solving skills!