The 'Class Companion' series is designed in accordance with the CBSE syllabus. It provides supplementary content and learning resources for the school-students of higher grades seeking to solve additional problems and thereby succeeding in their academic and competitive pursuits. The interactive learning design makes learning enjoyable. Inclusion of diverse range of practice exercises— from questions that reinforce learning to questions that tickle the analytical mind to improve students' problem-solving skills. The aim of this series is not only to improve performance in regular examinations but also to aid the development of skills needed to crack the competitive examinations. An invaluable resource for teachers and students, the Class Companion will simplify both teaching and learning. Now, learning will not be complete without the 'Companion'!