Two wall clocks are synchronized at noon. One clock gains 2 minutes every hour, while the other loses 3 minutes every hour. How many hours will elapse before their displays show a difference of exactly one full hour?
12 hours
Every hour, the fast clock pulls 2 minutes ahead and the slow clock falls 3 minutes behind, creating a 5-minute gap each hour. To reach a 60-minute gap, it takes 60 divided by 5, which equals 12 hours.
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: Easy. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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