Freddy the mathematical fly, who we met in WMC 141, has picked out two points A and P on the x-y plane at random – let’s say their co-ordinates are (a, b) and (p, q) respectively.  He decides to crawl around the perimeter of the rectangle with corners (a, b), (a, q), (p, b) and (p, q). What is the probability that he walks across the x-axis? Or the y-axis? What is the probability that his route goes around the point (0, 0)?