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       #Post#: 425--------------------------------------------------
       100 coins riddle
       By: dinesh Date: January 28, 2013, 2:52 am
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       Riddle: 100 coins, 90 heads, 10 tails.?
       You're in a completely black room. Scattered on the floor are
       100 coins - 90 of these are heads up and 10 of these are tails
       up. You are unable to distinguish which coins are heads or tails
       by touch or any other method you can think up.
       How do you separate the 100 coins into 2 piles, so that both
       piles contain the same number of face up tails?
       #Post#: 452--------------------------------------------------
       Re: 100 coins riddle
       By: adi Date: February 15, 2013, 10:09 am
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       we have 90 heads and 10 tails.
       this is the only knowledge we have..
       so we separate any coins into groups of 10 and 90.
       Now we flip all the coins in the 10 coins pile
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