Students learn how mutually exclusive and exhaustive events are represented in a Venn diagram and probabilities that add up to one. As learning progresses they use mutually exclusive events to calculate the probability of an event not happening.

The start of the lesson recaps Venn diagrams and set notation. The end of the lesson challenges students to describe why a two events are mutually exclusive and use it to calculate a probability.

**Differentiated Learning Objective**

- All students should be able to identify mutually exclusive events.
- Most students should be able to understand that the probabilities of all possible outcomes sum to 1.
- Some students should be able to calculate the probability of an event not happening.