Students of the competitive exams have always found it difficult to get precise and relevant material on the subject. They needed a book that could offer them maximum knowledge in the shortest possible time. With this objective in mind, unnecessary details have been weeded out while compiling this book. I hope this endeavour of mine will live up to the expectations of students of competitive exams. I have taken special care that the language used in the book is supple and lucid. After acknowledging the boundless blessings of Almighty, my profound regards are also due to my beloved parents, especially my father Ch. Bashir Ahmad and other family members for their endless love, prayers and encouragement. I feel special indebtedness to Miss Mudassir Mustafa for her continuous support. Her invaluable help of constructive comments and suggestions throughout this work would Iftsh’g&1l} contribute to the success of this publication. I would like to take this opportunity to say warm thanks to my valued friends M/s Ahmad Taimoor Ranjha, Muzainmil Nadeem and Hafiz Khawar Basheer Abmad, who have been so supportive along the way of doing my research work.