🔢 Permutation & Combination Simulator
CombinatoricsWhat's happening? nPr counts ordered arrangements, nCr counts unordered selections. nPr = n!/(n-r)!, nCr = nPr/r!. Watch how fast these grow!
Permutations & Combinations is a core concept tested across JEE Main and Advanced.
Understanding this concept visually builds the intuition you need to solve numerical problems faster and avoid common mistakes.
Key formula
Permutations & Combinations Formula
Core Formula
nPr = n!/(n-r)!, nCr = n!/(r!(n-r)!)
Adjust the sliders above and watch how changing each variable affects the result in real time.
JEE Application
This concept appears in both numerical and conceptual questions. Master the formula and the visual intuition together.
Step-by-step
How to approach Permutations & Combinations problems
- Identify the variables — list what's given and what's asked.
- Apply the core formula — nPr = n!/(n-r)!, nCr = n!/(r!(n-r)!).
- Check units — convert to SI units before calculating.
- Verify with intuition — does the answer make physical sense?
Common mistakes
What students get wrong
❌ Wrong units
Always convert to SI units before plugging into formulas.
❌ Forgetting sign conventions
Direction matters. Set up your coordinate system first.
FAQs
Permutations & Combinations Questions
How does this concept appear in JEE?
Expect 1-2 questions per paper. Focus on understanding the relationship between variables visually.
What's the most common mistake?
Using wrong units or forgetting to convert. Always check your units first.