Permutations

What you'll learn

1. Evaluate factorial expressions including n!, 0! = 1, and expressions like n!/(n-r)!
2. Explain why order matters in permutations and identify real-world situations that require permutations
3. Apply the permutation formula P(n,r) = n!/(n-r)! to count the number of ordered arrangements of r items chosen from n items
4. Solve applied problems involving permutations (rankings, arrangements, codes)

Prerequisites

• Fundamental counting principle