The theory of probability has been one of the most difficult and confused topics for students as well as teachers of Mathematics. At the same time we cannot ignore this topic if (i) we wish to (ii) get success in the Engineering Entrance Examinations. In order to make the topic easier a summary of the topic at the end of the book has been given. Each chapter contains theoretical introductions, definitions, theorems and formulae with proofs and explanations. In addition, exercises containing twenty years questions asked in various Engineering Entrance Examinations have also been given with detailed solutions.