## Applied Mathematics## Probability Theory |

## What is the law of total probability? |

The law of total probability can be written as follows: The probability that an event *A* will occur, P(*A*), is equal to the probability that event *A* and event *B* both occur, plus the probability that event *A* and event *B*' occur (or *A* occurs and *B* does not). Using the multiplication rule, this is written as: