Train A departs Station X heading East at 60 mph. At the exact same moment, Train B departs Station Y heading West at 40 mph on the same track. If the stations are 100 miles apart, how far apart are the two trains exactly one hour before they collide?
100 miles
The trains close the gap between them at a combined speed of 60 + 40 = 100 mph. Therefore, exactly one hour before impact, they must be 100 miles apart.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Easy. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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