Probability theory
Combinatorics in probability
Outcome counts, sampling and hypergeometric models.
Probability theory
Permutations of n elements
Pₙ = n!→Probability theoryPermutations with repetition
P = n!/(n₁!n₂!…)→Probability theoryNumber of unordered samples
Cₙᵏ→Probability theoryNumber of ordered samples
Aₙᵏ→Probability theoryIndependent trials outcome count
N = mⁿ→Probability theoryHypergeometric probability
P(X=k)=C(K,k)C(N−K,n−k)/C(N,n)→Probability theoryProbability all birthdays are distinct
P = 365·364·…/(365ⁿ)→