Types of Tree Diagrams There are many different types of tree diagrams, including probability trees, each of which serves a different purpose. Here are some of the most common types of tree diagrams: ...

Tree diagrams are a way of showing combinations of two or more events. Each branch is labelled at the end with its outcome and the probability is written alongside the line.

We can use the OR rule to calculate the probability: P (1 red and 1 blue) = 9 56 + 20 56 = 29 56 Often we use tree diagrams to model conditional probability.