Year 9 - Maths
Problem solving with possible outcomes
Probability: possible outcomes
Study Hub
Study Guides
This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit introduces and explores the concept of liklihood as a relative measure, and demonstrates multiple ways to represent likelihood such as Venn diagrams, tree diagrams and two-way tables.
Lesson Summary
You will learn to choose an appropriate diagram to display the outcomes for different events.
Key Notes
- The possible outcomes can be displayed for two or more events using an appropriate diagram.
- The various diagrams can be evaluated and the appropriateness of each diagram decided.
- The likelihood of an outcome can be determined using a mixture of different diagrams.
Vocabulary To Learn
- Likelihood: Likelihood describes the chance that a particular event occurs.
- Outcome table: An outcome table is a table that shows all the possible outcomes.
- Outcome tree: Each branch of an outcome tree shows a possible outcome from an event or from a stage of a trial. The full outcome tree shows all possible outcomes.
- Venn diagram: Venn diagrams are a representation used to model statistical/probability questions. Commonly circles are used to represent events.
Common Mistakes To Avoid
- Outcome tables and outcome trees only work for outcomes that are all equally likely.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
The possible outcomes can be displayed for two or more events using an appropriate diagram. The various diagrams can be evaluated and the appropriateness of each diagram decided.
2. Use this key word in a maths sentence and explain it clearly. 'Likelihood'
Likelihood describes the chance that a particular event occurs. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Outcome tables and outcome trees only work for outcomes that are all equally likely. Correction: Outcome tables can be separated into more rows and columns, and outcome trees split into more branches, to show outcomes that are more or less likely than other ones. This does mean these diagrams do get massive very quickly!
More Lessons In This Unit
- Comparing representations of outcomes for more than two events Study Guide
- Comparing representations of outcomes for two events Study Guide
- Equally likely outcomes Study Guide
- Experiments to determine how likely an outcome is Study Guide
- Non-equally likely outcomes Study Guide
- The scale of likelihoods Study Guide
- Using a Venn diagram to display outcomes for more than two events Study Guide
- Using a Venn diagram to display outcomes for two events Study Guide
- Using an outcome tree to display outcomes for more than two events Study Guide
- Using an outcome tree to display outcomes for two events Study Guide
- Using lists to display outcomes for more than two events Study Guide
- Using lists to display outcomes for two events Study Guide
- Using two-way tables to display outcomes for two events Study Guide
Browse all guides in the Year 9 Maths guide library.