If n biscuits are distributed among N different beggars, what is the probability that a particular baggar gets exactly r biscuits ?
a. ⁿCᵣ(N−1)ⁿ⁻ʳ⁻¹/Nⁿ
b. ⁿCᵣr(N−1)ⁿ/Nⁿ
c. ⁿCᵣ(N−1)ⁿ⁻ʳ/Nⁿ
d. ⁿCᵣ(N−1)ʳ/Nⁿ