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 Names in Boxes (Posted on 2017-04-09)
The names of 100 prisoners are placed in 100 wooden boxes, one name to a box, and the boxes are lined up on a table in a room. One by one, the prisoners are led into the room; each may look in at most 50 boxes, but must leave the room exactly as he found it and is permitted no further communication with the others.
The prisoners have a chance to plot their strategy in advance, and they are going to need it, because unless every single prisoner finds his own name all will subsequently be executed.
Find a strategy for them which has probability of success exceeding 30%.

Comment: If each prisoner examines a random set of 50 boxes, their probability of survival is an unenviable 1/2100 ∼ 0.0000000000000000000000000000008. They could do worse—if they all look in the same 50 boxes, their chances drop to zero. 30% seems ridiculously out of reach—but yes, you heard the problem correctly!

 Subject Author Date re(2): This is not possible - further thoughts. broll 2017-04-12 16:09:14 re(3): Loops Charlie 2017-04-12 14:41:51 re(2): Loops Jer 2017-04-12 13:27:25 re(2): Loops Brian Smith 2017-04-12 13:08:19 reference and solution xdog 2017-04-12 12:42:48 re: Loops Charlie 2017-04-12 10:54:02 Loops Brian Smith 2017-04-12 10:11:43 re: This is not possible. broll 2017-04-12 02:36:48 This is not possible. Math Man 2017-04-11 08:20:11 Thoughts Jer 2017-04-10 15:31:03

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