MathDB
2022 Combo Div 2 P1

Source:

February 28, 2022
combinatorics

Problem Statement

A particle starts at (0,0,0)(0,0,0) in three-dimensional space. Each second, it randomly selects one of the eight lattice points a distance of 3\sqrt{3} from its current location and moves to that point. What is the probability that, after two seconds, the particle is a distance of 222\sqrt{2} from its original location?
Proposed by Connor Gordon