http://www.theodorenguyen-cao.com/2008/02/02/puzzle-100-doors/ Personal blog of Theodore Nguyen-Cao Tue, 18 Oct 2011 16:28:18 +0000 hourly 1 http://wordpress.org/?v= http://www.theodorenguyen-cao.com/2008/02/02/puzzle-100-doors/comment-page-1/#comment-2281 Problem Solving: Doors in a long hallway | The Cornergeek Blog Sun, 07 Aug 2011 02:04:55 +0000 http://blog.notedpath.com/2008/02/02/puzzle-100-doors/#comment-2281 [...] There are 100 doors in a long hallway. They are all closed. The first time you walk by each door, you open it. The second time around, you close every second door (since they are all opened). On the third pass you stop at every third door and open it if it’s closed, close it if it’s open. On the fourth pass, you take action on every fourth door. You repeat this pattern for 100 passes. Question: At the end of 100 passes, what doors are opened and what doors are closed? (source: A Noted Path by Theodore Nguyen-Cao) [...] [...] There are 100 doors in a long hallway. They are all closed. The first time you walk by each door, you open it. The second time around, you close every second door (since they are all opened). On the third pass you stop at every third door and open it if it’s closed, close it if it’s open. On the fourth pass, you take action on every fourth door. You repeat this pattern for 100 passes. Question: At the end of 100 passes, what doors are opened and what doors are closed? (source: A Noted Path by Theodore Nguyen-Cao) [...]

]]> http://www.theodorenguyen-cao.com/2008/02/02/puzzle-100-doors/comment-page-1/#comment-1450 Saurabh Wed, 27 Jan 2010 20:45:11 +0000 http://blog.notedpath.com/2008/02/02/puzzle-100-doors/#comment-1450 damn good explanation. damn good explanation.

]]> http://www.theodorenguyen-cao.com/2008/02/02/puzzle-100-doors/comment-page-1/#comment-1433 Saurabh Wed, 27 Jan 2010 15:45:11 +0000 http://blog.notedpath.com/2008/02/02/puzzle-100-doors/#comment-1433 damn good explanation. damn good explanation.

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