Drawing a tree diagram

One fork per stage, a probability on every branch, and each fork totalling one.

Multiplying along the branches

The probability of a complete route as the product of its branch probabilities.

Adding across the paths

Finding every path that satisfies the event, then adding their probabilities.

Tree diagrams without replacement

Second-stage branches recalculated after the first pick, never simply copied.

Practice

Drawing a tree diagram

One fork per stage, a probability on every branch, and each fork totalling one.

Practice

Multiplying along the branches

The probability of a complete route as the product of its branch probabilities.

Practice

Adding across the paths

Finding every path that satisfies the event, then adding their probabilities.

Practice

Tree diagrams review

With and without replacement.

Mixed review