Let’s denote the arrival times of Lil and Bill by L and B, respectively, where L and B are taken as independent and uniformly distributed random variables over the interval 0 to 30 (0 means arriving at 3:30 and 30 means arriving at 4 o’clock). Obviously, if L < B, then Lil arrives first, and otherwise (L > B) Bill arrives first. So, we can now immediately write
if L < B, then Lil and Bill will meet if B — L < 5
if L > B then Lil and Bill will meet if L — B < 7.
Figure S2.1 shows the geometric ...