Question 547248
At 10:40 PM, train B will be 0 miles past the station. {{{x}}} hours after that, it will be {{{90x}}} miles past the station.
At 10:40 PM, train A will be 40 miles past the station, after traveling away from that station for 30 minutes (0.5 hours), covering 40 miles since 10:10 PM. {{{x}}} hours after 10:40 PM, train A will be {{{40+80x}}} miles away from that station.
At some point they will be the same distance from that station, and train B will be overtaking train A. At that point, we will have:
{{{90x=40+80x}}} --> {{{10x=40}}} --> {{{x=4}}}
So, 4 hours after 10:40 PM, both trains will be at the same distance from the station and a few passengers in train B will be waving at a few passengers in train A, as B passes A. The rest of the passengers will probably be asleep, because it will be 2:40 AM.