This textbook has been written according to the new revised syllabus of West Bengal University of Technology for the third year B Tech. (CSE???Fifth Semester & IT???Sixth Semester) students. It consists of seven chapters. This book can also be treated as a supplementary book of Discrete Mathematics for BE/BTech./BSc./BCA/MSc./ME/MTech./MCA students of other universities institutes. This book contains various types of problems along with worked out model problems which are essential to the Engineering/Technological/Science students. Multiple choice questions with answers provided in this textbook will be helpful for GATE and other competitive examinations.