MathDB
2022 W CHMMC Tiebreaker 1 - match of tennis with probabilities

Source:

March 2, 2024
combinatoricsCHMMC

Problem Statement

Yor and Fiona are playing a match of tennis against each other. The first player to win 66 games wins the match (while the other player loses the match). Yor has currently won 22 games, while Fiona has currently won 00 games. Each game is won by one of the two players: Yor has a probability of 23\frac23 to win each game, while Fiona has a probability of 13\frac13 to win each game. Then, mn\frac{m}{n} is the probability Fiona wins the tennis match, for relatively prime integers m,nm,n. Compute mm.