A wall clock strikes once at 1 o'clock, twice at 2 o'clock, and so on. It takes 6 seconds to complete striking at 4 o'clock. How many seconds will it take to complete striking at 10 o'clock?
18 seconds
Striking 4 times involves 3 intervals between strikes, taking 6 seconds, meaning each interval takes 2 seconds (6 / 3). Striking 10 times involves 9 intervals, taking 9 × 2 = 18 seconds.
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: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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