16. The starting and terminal stations of a tram line are Station A and Station B, respectively. A tram departs from Station A to Station B every 5 minutes, and the entire journey takes 15 minutes. A person starts cycling from Station B to Station A along the tram route. When he departs, a tram happens to arrive at Station B. On the way, he encounters 10 trams coming in the opposite direction before reaching Station A. At this point, a tram happens to be departing from Station A. How many minutes did it take him to travel from Station B to Station A?
16. 【Solution】Since trams are dispatched every 5 minutes and it takes 15 minutes to complete the entire journey, the tram seen by the cyclist at station B was dispatched 15 minutes ago. It can be deduced that when the cyclist set off from station B, the fourth tram was just leaving station A. During the time the cyclist took to travel from station B to station A, trams dispatched from station A were from the 4th to the 12th. A total of 9 trams were dispatched, with 8 intervals between them. Therefore: $5 \times 8 = 40$ (minutes).