The course contents of this book have been designed for students who appear in the different level examinations conducted by DOEACC. These levels are O-level, A-level, B-level and C-level. The most popular among these is the O-level, as it is the entry level. Once you have cleared the O-level, you are eligible for a government job. Each course has been divided into various modules. A number of books and available for various modules. But this book would be judicious choice for you to prepare for the O-level examination.