5 dice, probability that a player achieves at least four 6’s in a round
Source: 2020 Dürer Math Competition Finals Day2 E+13 https://artofproblemsolving.com/community/c1622639_2020_
January 7, 2022
probabilitycombinatorics
Problem Statement
In the game of Yahtzee , players have to achieve various combinations of values with dice. In a round, a player can roll the dice three times. At the second and third rolls, he can choose which dice to re-roll and which to keep. What is the probability that a player achieves at least four ’s in a round, given that he plays with the optimal strategy to maximise this probability?Writing the answer as where and are coprime, you should submit the sum of all prime factors of , counted with multiplicity. So for example if you obtained then the submitted answer should be .