This book has been carefully structured in accordance with the model syllabus prescribed by the University Grants Commission (UGC), India. It is ideally suited for undergraduate students pursuing B.Tech in Computer Science and Engineering or Mathematics, as well as postgraduate students enrolled in M.C.A. (Master of Computer Applications) or M.Sc. Mathematics programs.To make the book self-contained and accessible, it begins with foundational chapters on Mathematical Logic and Set Theory, which are essential components of the curriculum. Building upon these basics, the book introduces a wide array of key topics relevant to both Computer Science and Mathematics, including Combinatorics, Graph Theory, and Algebraic Structures such as Groups, Rings, and Boolean Algebra.In addition to traditional topics, the book includes important subjects like Finite State Machines (Theory of Computation) and Probability, making it a comprehensive guide for students navigating the intersection of mathematics and computer science.The content is presented in a simple, lucid, and student-friendly manner, with numerous examples and applications that demonstrate the practical relevance of abstract concepts, especially in the domain of Computer Science.To enhance its academic scope, the book also offers a final chapter on Fuzzy Set Theory-a modern extension of classical set theory-introducing students to contemporary topics in mathematical reasoning and logic. Overall, it is an excellent academic and reference resource.