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There's a broken clock. the interval between its two ticks is longer than usual so that it loses 6 minutes an hour.

How many ticks should a blind person hear so that he/she be informed of real 6 minutes past?

P.S. I have seen this puzzle in a non-English puzzle quiz and translated it.

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324

Because:

60 minutes pass when the clock counts only 54 minutes.
So 6 minutes pass when the clock counts 5.4 minutes.
5.4 minutes = $60 \times 5.4$ ticks = 324

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a blind person should count:

328 ticks

A "normal" clock ticks 1 time per second so 3600 times per hour. Now our clock ticks the same amount of times in 66 minutes or 3960seconds. the interval between 2 ticks is 3960/3600 = 1.1s .

To get 6 minutes a blind person would need to count 360/1.1

= 327.2727... times

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  • $\begingroup$ Marius did it well. take a look at it. $\endgroup$
    – aminabzz
    Aug 10 '20 at 13:14

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