This is the "correct" statement:
"We need to have 20 high-speed train departures each way every day between Beijing and Shanghai. For instance, say an hourly departure between 4am and 11pm.
Given our one-way travel time of 3 hours and say, another hour for cleaning, unloading, train inspection, etc., we need at least 4 trains for hourly departure in both Beijing and Shanghai, for a total of 8 trains at least."
Does this make sense? If so, why? If not, what is the correct number of trains needed?
Thank you and happy new year!