Mathematics is a beautiful and interesting branch of study and has wide spread use in many areas of life. However, many students have unnecessary fear of mathematics. Our effort in this book has been to present the theory, examples and questions a logical sequence so as to develop and strengthen the concepts. These days, students have wide career options available to them after class XII. Mathematics is useful not only to engineering stream students, but it has wide use in higher studies in the fields of Economics, Commerce, Social Science and even in Liberal Arts. Use of logical reasoning, algebraic methods as representation and as problem solving tools; statistical tools etc. cuts across multiple disciplines. This enables the students to appreciate the power of Mathematics and Data in contemporary society. The theory has been explained in simple language and includes many examples from real life situations. Emphasis has been laid on basic facts, concepts, terms, principles and on the application of various concepts. Carefully selected examples consist of detailed step-by-step solution. In particular, teaching material provided by CBSE has been taken care of. The book has been revised according to the reduced syllabus. Assertion-Reason type questions have also been added.