Dependent events
- Update totals after each event.
- Change probabilities if there is no replacement.
- Multiply along branches if needed.
Answer: 5 counters become 4 after one is taken
🎲 Probability
Dependent events
Learn dependent events with a GCSE-style explanation, help guide, worked example, practice question and flashcards.
Global XP
Level 10 / 100 XP
1. Explanation
Key idea
- Dependent events is part of probability and appears often in KS3–GCSE maths.
- Dependent events change the sample space.
- Use the worked model, help guide, interactive question and flashcards to practise dependent events until the steps feel automatic.
Real-life examples
- Shopping, sport, travel, science, design and everyday decisions all use this skill.
2. Visual
Dependent events learning map
Understand the key idea → follow the help guide → practise a question → check your method → build speed with flashcards.
3. Help guide
How to tackle Dependent events
- Learn the rule: Dependent events change the sample space.
- Worked model: Update totals after each event. Change probabilities if there is no replacement. Multiply along branches if needed.
- Try the interactive question without looking at the answer first.
- Use the flashcards to test the rule, the method and a common check.
4. Worked examples
Step-by-step working
5. Interactive questions
Try it yourself
A bag has 2 red and 3 blue counters. A red is taken and not replaced. How many counters remain?
6. Flashcards
Master quick recall
Flip each card, then choose whether you know it or need more practice.
0 mastered
FrontRule for Dependent events
BackDependent events change the sample space.
FrontExample answer: A bag has 2 red and 3 blue counters. A red is taken and not replaced. How many counters remain?
BackThere were 5 counters and one was removed, so 4 remain.
FrontCommon check for Dependent events
BackCheck units/notation, compare with an estimate, and make sure the answer matches the question.
7. Finish
Complete this topic
When you have read the examples, tried the question and reviewed flashcards, claim your topic completion XP.