Poker Hand Probability Interview Questions
Poker hand probability interview prep for unordered hands, combinations, ranks, suits, pairs, and common counting traps.
Candidates practicing combinations and deck-counting prompts for quant interviews.
Hands are unordered
Poker-hand prompts usually treat a hand as unordered. The denominator for a five-card hand is C(52,5), not 52 x 51 x 50 x 49 x 48, unless the prompt explicitly asks about draw order.
Break the structure into choices
For exact hand types, choose ranks and suits in a sequence that counts each hand once. The goal is not memorizing poker odds; it is building a clean counting model.
Concrete example
Exactly two aces in a five-card hand is C(4,2)C(48,3)/C(52,5). Choose two aces, choose three non-aces, divide by all five-card hands.
Pairs and ranks
For one pair, choose the paired rank, choose two suits for that rank, choose three other ranks, then choose suits for those cards. Each choice should avoid double-counting.
Check with symmetry
If a formula gives a probability above one or seems larger for a more restrictive hand type, stop. Poker-hand counts are especially vulnerable to double-counting.
Common mistakes
Candidates mix ordered and unordered counts or count the same hand multiple ways. Be able to explain exactly what object each factor chooses.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.