CSCA MathematicsChapter 4: Probability & StatisticsIntermediate
Permutations, Combinations & Classical Probability
排列组合与古典概型 · Node 4.1
Addition and multiplication counting principles, permutations $A_n^m = \frac{n!}{(n-m)!}$, combinations $C_n^m = \frac{n!}{m!(n-m)!}$, and equally likely outcomes.
Chapter Weight: 15% of official examination
Practice This NodeCore Mathematical Axiom
Formula Proof & TrapsCSCA Exam Trap Alert
Confusing permutation (ordered) with combination (unordered) in selection problems.