It has been revised and brought up-to-date in accordance with the latest syllabi, to meet the needs of the students and teachers alike. ? This book has been prepared to enable the students to give a correct and to the pint answer to questions set in the examination. ? The answers have been arranged under various heads and subheads to faciliate the students to remember various steps. In accordance with the modern style of questions have been included to cover the entire syllabus.