Click here to win prizes by solving the puzzle Advent calendar.
Click here to win prizes by solving the puzzle Advent calendar.




A dog is running along a beach at 2m/s. The dog's owner blow a whistle every 10 seconds. Each time the dog hears a whistle, she doubles her speed. How many whistles will the dog hear?
(Hint: speed of sound = 343m/s)
(Hint 2: The answer is not eight!)

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Tags: speed


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