1. The problem statement, all variables and given/known data I'm slightly confused as to how to work out the distribution of free paths (the distance a particle travels before colliding). Finding the mean free path is fine, but there are several questions that I'm currently attempting that would seem to need the distribution of path lengths rather than just the mean. 2. Relevant equations ?? 3. The attempt at a solution This isn't a question in it's own right, so I don't really have any meaningful working towards it (just jottings from parts of the questions I'm attempting, but out of context they'll mean nothing).