Inverse proportion
- Identify that one quantity increases while the other decreases.
- Keep the product constant.
- Scale in the opposite direction.
Answer: 2 taps take 12 min, 4 taps take 6 min
⚖️ Ratio, Proportion & Rates
Inverse proportion
Learn inverse proportion with a GCSE-style explanation, help guide, worked example, practice question and flashcards.
Global XP
Level 10 / 100 XP
1. Explanation
Key idea
- Inverse proportion is part of ratio & proportion and appears often in KS3–GCSE maths.
- In inverse proportion, one quantity increases as the other decreases by the same factor.
- Use the worked model, help guide, interactive question and flashcards to practise inverse proportion until the steps feel automatic.
Real-life examples
- Shopping, sport, travel, science, design and everyday decisions all use this skill.
2. Visual
Inverse proportion 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 Inverse proportion
- Learn the rule: In inverse proportion, one quantity increases as the other decreases by the same factor.
- Worked model: Identify that one quantity increases while the other decreases. Keep the product constant. Scale in the opposite direction.
- 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
4 workers take 6 days. How long for 8 workers at the same rate?
6. Flashcards
Master quick recall
Flip each card, then choose whether you know it or need more practice.
0 mastered
FrontRule for Inverse proportion
BackIn inverse proportion, one quantity increases as the other decreases by the same factor.
FrontExample answer: 4 workers take 6 days. How long for 8 workers at the same rate?
BackWorkers double from 4 to 8, so time halves from 6 days to 3 days.
FrontCommon check for Inverse proportion
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.