Rule of Three (Inverse Proportion)
Solve inverse proportion problems where two quantities are inversely related — as one increases, the other decreases proportionally.
What Does This Tool Do?
In inverse proportion, if you increase one quantity, the other decreases by the same factor. Classic examples: more workers → fewer days to complete a task; faster speed → less time for a journey.
Key Features
Inverse Proportion
Solves A×B = C×D type problems.
Instant
Result calculated immediately.
Any Values
Works with any decimal values.
How to Use This Tool
- Enter values for A, B, and C.
- Click Solve D to find the missing value.
How It Works
Uses the formula D = (A × B) / C — inverse proportion cross multiplication.
Common Use Cases
💡 Work & Time
Calculate how long a task takes with different numbers of workers.
💡 Speed & Time
Find travel time at different speeds.
💡 Resources
Calculate resource requirements for different scales.
Frequently Asked Questions
How do I know if a problem is direct or inverse?
Ask: if the first quantity increases, does the second increase (direct) or decrease (inverse)? More workers → less time = inverse. More speed → more distance = direct.
Related Tools
Link to This Tool
Copy and paste the code below to link to this tool from your website:
<a href="https://adedx.com/tools/rule-of-three-inv/">Rule of Three (Inverse Proportion) — AdeDX Free Online Tools</a>