Brain Teasers
Mad Ade's Watches
Mad Ade has 3 timepieces in his house - a wall clock, an alarm clock and a wristwatch. The wristwatch is always accurate, whereas the wall clock gains 2 minutes every day and the alarm clock loses 2 minutes every day.
At exactly midnight last night, all three watches were showing the same time.
If today is 25 July 2003, then on which date all three clocks will show the same time again?
At exactly midnight last night, all three watches were showing the same time.
If today is 25 July 2003, then on which date all three clocks will show the same time again?
Answer
All three clocks will show the same time again at midnight between 18 July 2004 and 19 July 2004.A clock finishes one complete 12 hour cycle in 12*60 i.e. 720 minutes.
If a clock gains 2 minutes every day, then it would be 720 minutes ahead after 360 days. Thus, after 360 days, it will show the same time again.
Similarly, if a clock loses 2 minutes every day, then it would be 720 minutes behind after 360 days. Thus, after 360 days, it will show the same time again.
Thus, after 360 days all three clocks will show the same time again i.e. midnight between 18 July 2004 and 19 July 2004. Do not forget that 2004 is a leap year, so 25 July 2004 is 366 days after 25 July 2003.
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Comments
On which date WILL all three clocks show the same time again? It will be the date July 19th 2004. Fair puzzle!
except that 2004 is a leap year, so the correct date will be July 18th.
I liked it
I don't know and I don't care. Mickey Mouse's underwear.
there's 365 days in a year
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