MathDB
2022 MMATHS Team Online p11 - 3 emojis: barbecue, bacon, or burger

Source:

October 1, 2023
probabilitycombinatoricsMMATHS

Problem Statement

Every time Josh and Ron tap their screens, one of three emojis appears, each with equal probability: barbecue, bacon, or burger. Josh taps his screen until he gets a sequence of barbecue, bacon, and burger consecutively (in that specific order.) Ron taps his screen until he gets a sequence of three bacons in a row. Let MM and NN be the expected number of times Josh and Ron tap their screens, respectively. What is MN|M-N|?