Question

Trains A and B are traveling in the same direction on parallel tracks. Train A is traveling at 40mph and Train B at 50mph. Train A passes a station at 9:20 am. If train B passes the same station at 9:32 am, at what time will train B catch up to train A?

Answer 1

let the time passed from 9:32 til train B catches up to A be t hrs.

When B passes the station, train A will have traveled 12 minutes at 40 mph or 40(12/60) miles or 8 miles.

So when B catches A,
train A is (8 + 40t)miles past the station
train B is 50t miles past the station

but these two distances are the same, so
50t = 8 + 40t
10t = 8
t = 8/10 hours = 48 minutes

so the meet at 9:32 + 0:48
= 10:20 am