Year 9 - Maths
Non-equally likely outcomes
Probability: possible outcomes
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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 state when outcomes will not be equally likely.
Key Notes
- Events with outcomes that are likely to not be equally likely can be identified
- Outcomes that are not equally likely can be identified and compared
- Factors can be identified that can cause one outcome to be more/less likely than another
Vocabulary To Learn
- Event: An event is a subset of a sample space. It could be a particular outcome or be a set of outcomes that may occur from a trial.
Common Mistakes To Avoid
- The outcomes of a trial are always equally likely to occur (e.g. each of the two players in a tennis match are equally likely to win).
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Events with outcomes that are likely to not be equally likely can be identified. Outcomes that are not equally likely can be identified and compared.
2. Use this key word in a maths sentence and explain it clearly. 'Event'
An event is a subset of a sample space. It could be a particular outcome or be a set of outcomes that may occur from a trial. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: The outcomes of a trial are always equally likely to occur (e.g. each of the two players in a tennis match are equally likely to win). Correction: There are factors that may affect how likely one outcome is compared to another (e.g. the skill or experience of one tennis player compared to the other).
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
- Problem solving with possible 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.