A train leaves the station at 6 pm traveling west at 80 mph

A train leaves the station at 6 pm traveling west at 80 mph. On a parrell track, a second train leaves the station 3 hours later traveling west at 100 mph. At what time will the second train catch up with the first?

Solution

they start out 240 miles apart, the second train is overtaking at 20 mph
240/20=12 hrs to overtake
6+3=9 pm + 12=9 am