Aims at the level between that of elementary probability texts and advanced works on stochastic processes. The prerequisites are a course on elementary probability theory and statistics and a course on advanced calculus. The theoretical results developed have been followed by a large number of illustrative (worked) examples. These have been supplemented by numerous exercises, answers to most of which are also given. It is expected to suit as a text for advanced undergraduate, postgraduate and research level courses in Applied Mathematics, Statistics, Operations Research, Computer Science, different branches of Engineering, Telecommunications, Business and Management, Economics, Life Sciences and soon. A review of the Ist edition of the book in the American Mathematical Monthly (December 1982) gives this book special positive emphasis as a textbook as ?the clear choice? amongst about a dozen or more texts (TAV). A review of the 2nd edition (1994) in the Journal of the Operational Res. Society, U.K. (1996) commended it ?As before it rightly deserves to be ?nominated? as the first choice? (Jim Freeman).