Skip to content # Monty Hall Problem

## Activity Guide

# This guide looks at the activity in detail and goes into the underlying math.

Contributor(s): David Klein, Spencer Bowen

Math Circles: San Francisco Math Circle

- Activity Description
- Topics Covered
- Session Styles
- Mathematical Practices

A prize is hidden behind one of three doors. You choose the door where you think the prize is hidden. But before the door is opened, one of the other 2 remaining doors is opened to reveal no prize. You can choose to keep the door you chose earlier or switch to the other remaining door. What should you do?