MathDB
Skull,coin possibility

Source: 2021 Taiwan APMO Preliminary First Round

November 21, 2020
combinatoricspossibility

Problem Statement

Let a board game has 1010 cards: 33 skull cards, 55 coin cards and 22 blank cards. We put these 1010 cards downward and shuffle them and take cards one by one from the top. Once 33 skull cards or coin cards appears we stop. What is the possibility of it stops because there appears 33 skull cards?
Back to ProblemsView on AoPS