# Lesson 6: Bayes' Theorem

### Introduction

In this lesson, we'll learn about a classical theorem known as Bayes' Theorem. In short, we'll want to use Bayes' Theorem to find the conditional probability of an event *P*(*A *| *B*), say, when the "reverse" conditional probability *P*(*B *|* A*) is the probability that is known.

### Objectives

- Learn how to find the probability of an event by using a partition of the sample space
*S*. - Learn how to apply Bayes Theorem to find the conditional probability of an event when the "reverse" conditional probability is the probability that is known.