Two watches


The two watchesI started two watches at the same time and found that one went two minutes an hour too slow and the other one minute an hour too fast, so that when I looked at them again the faster one was exactly one hour ahead. Can you figure out from from the picture at what time before noon the watches must have started?

This problem was first posted by American puzzle genius Sam Loyd. It was incorporated into his Cyclopedia of Puzzles on page 30.

You can check your solution here

You are welcome to remark on the quirks in the puzzle, and i especially welcome your solution times. The solutions itself will be published after one week.

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One thought on “Two watches

  1. Yes and no. It would take 20 hours for the fast clock to display a time exactly 1 hour ahead of the slow clock ASSUMING the clocks started at the same time AND displayed the same time when they started. (Assuming this is the case perhaps it should be reworded to state this?)
    Secondly it’s not possible to know when the watches started because we’re not told if the image is of the fast or slow watch.
    Assuming it’s of the fast watch they must have been started 20h20m before the displayed time which would be 12:45:25am.
    If it’s an image of the slow watch they must have been started 19h20m before the displayed time which would be 01:45:25am.

    It’s just barely implied that the image is of the fast one but that should be clearly stated. Time taken to solve this about 1 minute, time spent deliberating over my solution and doubting myself due to the wording of the question – very long!.

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