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Puzzle ZHBL 



??

I recently gave a new carriage clock to my friend for a very special birthday.

However, as usual with my presents, it was quite useless as it loses 6 minutes every hour.

I set it using my own accurate clock at midnight and the clock now shows 10:12am.

I know that it stopped 2 hours ago, so what is the correct time now?

Puzzle Copyright © Kevin Stone

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Answer
1:20pm.

Reasoning
The clock now shows 10:12am, so we know that 10 x 60 + 12 = 612 clock minutes have passed.

Since the clock is losing 6 minutes every hour, for every real hour that has passed the clock will show 54 minutes.

So, 612 ÷ 54 ≈ 11.33 real hours have passed.

This equals 680 minutes, which is 11 hours and 20 minutes = 11:20am.

The clock stopped 2 hours ago, therefore the time must now be 1:20pm.

 

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