This volume offers a comprehensive collection of exercises, problems, and fully worked solutions covering the core topics of a first course in probability. Each chapter opens with a concise overview of essential probabilistic tools — such as distributions, transforms, martingales, and Gaussian processes — followed by examples that illustrate key techniques and applications.This substantially revised second edition introduces numerous new exercises, enhances the treatment of discrete and continuous distributions, and includes strengthened sections on martingale inequalities and Gaussian processes. Ideal for building intuition and confidence, the book provides clear reasoning, rigorous solutions, and broad coverage of classical and modern topics in probability and stochastic processes.