Year 11 - Maths
Checking and securing exhaustive events
Conditional probability
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit, pupils use their knowledge of calculating theoretical probabilities and extend it to calculate conditional probabilities.
Lesson Summary
You will learn to work with probabilities as fractions, decimals and percentages and use the fact that exhaustive events sum to 1.
Key Notes
- Probabilities can be given as fractions, decimals or percentages
- An event is exhaustive if all possible outcomes are included
- The probability of an exhaustive event is 1 and this can be used to calculate missing probabilities
Vocabulary To Learn
- Mutually exclusive: Two or more events are mutually exclusive if they share no common outcome.
- Exhaustive events: A set of events are exhaustive if at least one of them has to occur whenever the experiment is carried out.
Common Mistakes To Avoid
- Pupils may think that any set of probabilities relating to a scenario will always sum to 1.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Probabilities can be given as fractions, decimals or percentages. An event is exhaustive if all possible outcomes are included.
2. Use this key word in a maths sentence and explain it clearly. 'Mutually exclusive'
Two or more events are mutually exclusive if they share no common outcome. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Pupils may think that any set of probabilities relating to a scenario will always sum to 1. Correction: Probabilities sum to 1 when the events are exhaustive and mutually exclusive.
More Lessons In This Unit
- Advanced problem solving with conditional probability Study Guide
- Algebra in tree and Venn diagrams Study Guide
- Checking and securing calculating probabilities from diagrams Study Guide
- Checking and securing calculating probabilities from tables Study Guide
- Checking and securing displaying outcomes Study Guide
- Combinations Study Guide
- Comparing multiple representations to calculate conditional probabilities Study Guide
- Conditional probability in a tree diagram Study Guide
- Conditional probability in a two-way table Study Guide
- Conditional probability in a Venn diagram Study Guide
- Constructing three event Venn diagrams Study Guide
- Experimental probability Study Guide
- Experimental vs theoretical probability Study Guide
- Frequency trees Study Guide
- Probabilities in three event Venn diagrams Study Guide
- Probabilities involving algebra Study Guide
- Problem solving with conditional probability Study Guide
- Set notation Study Guide
Browse all guides in the Year 11 Maths guide library.