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How to Calculate Permutations
Formula
A permutation counts how many ways you can arrange r items from n total when order matters.
The formula is P(n,r) = n! / (n-r)!.
Common use cases:
- Arranging race finishing positions
- Creating unique PIN codes
- Scheduling ordered tasks
Frequently Asked Questions
Dr. David Park
Applied Mathematician, PhD Mathematics
David holds a PhD in Applied Mathematics from MIT. He has published research on numerical methods and computational algorithms used in engineering and scientific calculators.
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