Specialist Mathematics Β· Unit 1 Β· Combinatorics Β· Permutations (ordered arrangements) and combinations (unordered selections)

Use the notation 𝑃𝑛 π‘Ÿ to represent the number of ways of selecting π‘Ÿ objects from 𝑛 distinct objects where order is important. π‘ƒπ‘Ÿ 𝑛 = 𝑛! (π‘›βˆ’π‘Ÿ)! = 𝑛 Γ— (𝑛 βˆ’ 1) Γ— (𝑛 βˆ’ 2) Γ— … Γ— (𝑛 βˆ’ π‘Ÿ + 1)

Learning objective 10 of 10 in this subtopic