MathDB
2021 Spring LMT Division A Problem 30

Source:

January 22, 2022
combinatorics

Problem Statement

Ryan Murphy is playing poker. He is dealt a hand of 55 cards. Given that the probability that he has a straight hand (the ranks are all consecutive; e.g. 3,4,5,6,73,4,5,6,7 or 9,10,J,Q,K9,10,J,Q,K) or 33 of a kind (at least 33 cards of the same rank; e.g. 5,5,5,7,75, 5, 5, 7, 7 or 5,5,5,7,K5, 5, 5, 7,K) is m/nm/n , where mm and nn are relatively prime positive integers, find m+nm +n.
Proposed by Aditya Rao