## Problem of the Week 1201## What Goes Up Might Not Come DownA random walk on the 2-dimensional integer lattice begins at the origin. At each step, the walker moves one unit either left, right, or up, each with probability 1/3. (No downward steps ever.) A walk is a success if it reaches the point (1, 1). What is the probability of success?
Note: One can vary the problem by varying the target point. For example, use Source: Bruce Torrence, Randolph-Macon College. |

29 January 2015