One of each face before the two of hearts

A standard 5252-card deck is shuffled and dealt one card at a time until the 2♡2\heartsuit appears. What is the probability that exactly one King, exactly one Queen, and exactly one Jack appear before the 2♡2\heartsuit?

Show hints (2)+
  1. Only the 2♡2\heartsuit and the 1212 face cards matter. First: probability exactly 33 faces precede the 2♡2\heartsuit is 1/131/13 (its position is uniform among 1313).
  2. Then those 33 are a random 33-subset of the 1212 faces; chance of one each is (41)3/(123)\binom41^3/\binom{12}{3}.

Answer

Reveal answer →

0.0224 (± 0.001)

Create a free account to see the full worked solution and track your progress.

Interview format: Market Maker, Hedge Fund Quant

Related questions