Welcome to Probability 1 – 40 solved problems step-by-step solutions. This class is designed to help students who are struggling with an introductory probability course. Most of the time, students are not having enough chances to see the instructors to solve the problems step-by-step, but instead the instructors are giving out to them a ton of theoretical derivations. Therefore, in this course I will guide you through the most basics 40 fundamental problems and how to approach them. Before each question, you will be introduced with a quick background and any relevant formula required for the problems. Any student can take this class as it can also be an overall review of the basics probability theory. In order to start this course, you just need some basics knowledge for algebras and that’s it! After you complete this course, you will be surely to be prepared to move to higher probability and statistics level courses. The course is designed to be finished in a week to master the basics concepts including the counting principle, conditional probability, axiom of probability, and independent event.