Discrete Mathematics is designed as a textbook for undergraduate engineering students of computer science and postgraduate students of computer applications. The book seeks to introduce students to the mathematical concepts needed to develop logical reasoning, abstract thinking, and problem solving-important prerequisites for the study of computer science. The subject matter has been arranged so as to provide a clear and integrated approach to the subject with all essential tools of applicable mathematics required for BCA and graduate curriculum. The set of objects studied in discrete mathematics can be finite or infinite. The term finite mathematics is sometimes applied to parts of the field of discrete mathematics that deals with finite sets, particularly those areas relevant to business. Research in discrete mathematics increased in the latter half of the twentieth century partly due to the development of digital computers which operate in discrete steps and store data in discrete bits. Concepts and natations from discrete mathematics are useful in studying and describing abjects and problems in branches of computer science, such as computer algorithms, programming languages, cryptography. automated theorem proving, and software development. Conversely, computer implementations are significant in applying ideas from discrete mathematics to real-world problems, such as in operations research. The subject matter of the book has been adopted from various Indian and foreign books, exercises and real word cases. The idea is to provide all relevant and up-to-date information at one place so that readers of the book can have an idea about "Discrete Mathematics."