This book is written for students dealing with AC/DC. It is based on lecturing theory and giving example classes for more than a decade. Hundreds of books deal with the theory of electricity in a professional and educational manner. The aim of manuscript is not to be part of this valuable collection of these books but just a tool to guide and accompany the students to solve electricity problems in a pedagogical and easy man-ner. This manuscript tends to give the student the ability to analyse a circuit and from the additional information, calculate the required value and answer all type of ques-tions regarding the circuit under study. This book is divided into two parts. The first part deals with dc circuits with different ways of solving the same problem to let the student feeling the importance of some valuable theorems like superposition or Thevenin. In the second part, we discuss AC circuits with complex number calculation to emphasize the importance of some math-ematical conversions. Appendices at the end of the manuscript are as important as the solution of the problems.