Extremely well organised and lucidly written book with an approach to explain The concepts in communicable languages. Suitable text book for The students of BCA, B. Tech., M. C. A., M. Sc., M Tech., etc. Each Chapter follows objective type problems. Around 500 objective type problems (235) multiple choice questions, 130 fill in The blanks type, 135 true/false type with their answers to help students understand and very concept. Around 800 problems of various level of difficulty in exercises to review The understand and testing The skills of The students after every section. Around 140 theorems to give better understand and insights of The concepts. Topics are followed by figures and tables. In total more than 400 figures and 140 tables are taken to back The understand of topics. Chapter includes - combinatorics, set Theory, relations functions, group theory, rings and fields, logic, lattices, Boolean Algebra, graph theory, automata. table of Contents1 - combinatorics2 - set theory3 - Relations4 - Functions5 - groups6 - rings and fields7 - Logic8 - lattices9 - Boolean algebra10 - graph theory11 - automata.