If a train travels 60 miles in one hour, and then travels 60 miles back along the exact same track in 40 minutes, what was its average speed for the entire round trip in miles per hour?
72 miles per hour
Total distance = 120 miles. Total time = 60 mins + 40 mins = 100 minutes = 5/3 hours. Average speed = Total distance / Total time = 120 / (5/3) = 120 * 3 / 5 = 72 mph.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Hard. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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