wu :: forums - Print Page


    
      
        wu :: forums
        (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi)
      

        riddles >> easy >> turning cards??
        
(Message started by: valerfor on May 17^th, 2004, 7:35am)

Title: turning cards??
Post by valerfor on May 17^th, 2004, 7:35am

This puzzle is given by my lecturer and he has not released the solution yet :(
We are given a deck of 52 cards and 10 cards are overturned. The lights are off so we cannot see which are the overturned cards.
We are then required to seperate the deck into piles having the same number of overturned cards.
How do we go about doing it?

Title: Re: turning cards??
Post by towr on May 17^th, 2004, 8:20am

The piles only need to have an equal number of overturned cards, otherwise they may differ in size, and that helps..

You could try it with less cards first, like 6 cards with 2 turned over

Title: Re: turning cards??
Post by Cathos on May 17^th, 2004, 2:21pm

This one is similar to one of the coin-game riddles, I believe. It's very clever; I stumped everyone at work with it.

Title: Re: turning cards??
Post by Sir Col on May 17^th, 2004, 2:54pm

Just for clarity, are we saying that the pack of 52 cards has 10 face-up cards and 42 face-down cards randomly distrubuted throughout the pack? And we need to design a "blind-folded" method of creating piles containing the same number of face-up cards?

Title: Re: turning cards??
Post by towr on May 18^th, 2004, 12:02am

yes.
(I'm sure it's on the site in a different guise allready, but it seems impossible to find the thread)

Title: Re: turning cards??
Post by BNC on May 18^th, 2004, 1:20am

on 05/18/04 at 00:02:02, towr wrote:

yes.
(I'm sure it's on the site in a different guise allready, but it seems impossible to find the thread)

this one? (http://www.ocf.berkeley.edu/~wwu/cgi-bin/yabb/YaBB.cgi?board=riddles_hard;action=display;num=1027939038;start=8)

Title: Re: turning cards??
Post by towr on May 18^th, 2004, 4:21am

yep, that's the one.. I salute your l33t thread finding skilz ;)

Title: Re: turning cards??
Post by valerfor on May 18^th, 2004, 7:49am

hehe thanks guys!!! i tried looking for this puzzle in this site but just couldnt find it... the solution is simple and nice! thanks!