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Where two or three events occur, following on from each other, the various outcomes can be illustrated clearly on a tree diagram . This is particularly useful when later events depend in some way on the outcomes of previous events.
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Summary/Background

A tree diagram is used to illustrate probabilities when two things happen by displaying outcomes and their probabilities on the branches. For example when two coins are spun, or if someone takes a counter from one bag followed by a counter from another bag, then the possibilities are shown on a tree diagram. The diagram shows all the possible outcomes. Usually the probability of each individual outcome is marked on each branch.

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Glossary

tree

A connected graph with no cycles.

union

The union of two sets A and B is the set containing all the elements of A and B.

Full Glossary List