Below is an extract of a 10-page cheat sheet about probability, compiled by William Chen (http://wzchen.com) and Joe Blitzstein, with contributions from Sebastian Chiu, Yuan Jiang, Yuqi Hou, and Jessy Hwang. Material based on Joe Blitzstein’s Harvard's introductory probability course (@stat110 - (http://stat110.net) and Blitzstein / Hwang’s Introduction to Probability textbook (http://bit.ly/intr…