Permutation Calculator

Calculate the number of permutations (ordered arrangements) when choosing r items from n items.

P(n, r)

720

n!3,628,800
C(n, r) for comparison120

P(n, r) vs Total Items (n)

सूत्र देखें →

सूत्र

## How to Calculate Permutations ### Formula **P(n, r) = n! / (n - r)!** A permutation counts the number of ways to arrange r items chosen from n distinct items where order matters. For example, selecting a president, vice-president, and secretary from 10 people is a permutation problem because each position is different.

हल किया गया उदाहरण

How many ways can you arrange 3 books from a shelf of 10?

  1. 01P(10, 3) = 10! / (10 - 3)!
  2. 02= 10! / 7!
  3. 03= 10 * 9 * 8 = 720
  4. 04Compare with combinations: C(10,3) = 120 (order does not matter)