August 2016 Brain Teaser Solution

Q: In the “old days”, most people wore a watch and it was not always accurate.  A friend had a watch that gained 6 minutes every hour.  If this watch is set accurately at midnight and the watch stopped a half hour ago and it now shows 8:26AM, what is the current correct time?

A: The watch is gaining 6 minutes every hour, for every hour, the watch will show 66 minutes. Since the watch shows 8:26 am, we know that 506 watch minutes have passed which is 460 real minutes (506 x 60/66 ) = 7 hrs and 40 minutes which would make it 7:40.
The watch stopped 30 minutes ago, therefore the time must now be 8:10 am.

 

 

 

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