100 prisoners are put into solitary cells. There's a central living room with one light bulb; the bulb is initially off. No prisoner can see the light bulb from his or her own cell. Every day, the warden picks a prisoner at random, and that prisoner goes to the central living room. While there, the prisoner can toggle the bulb if he or she wishes. Also, the prisoner has the option of asserting the claim that all 100 prisoners have been to the living room. If this assertion is false (that is, some prisoners still haven't been to the living room), all 100 prisoners will be shot for their stupidity. However, if it is indeed true, all prisoners are set free and inducted into MENSA, since the world can always use more smart people. Thus, the assertion should only be made if the prisoner is 100% certain of its validity.
The prisoners are allowed to get together one night, to discuss a plan. What plan should they agree on, so that eventually, someone will make a correct assertion?
(From http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml)
(In reply to
This seems stupidly easy... by thegnome54)
Quote from the puzzle: "100 prisoners are put into solitary cells" (emphasis added)
Quote from the puzzle: "
The prisoners are allowed to get together one night, to discuss a plan. " (emphasis added)
Quote from thegnome54: "Every night at the meeting ..." (emphasis added)
Quote from thegnome54: "This seems stupidly easy" (emphasis added)
Quote from Vernon Lewis: "Problems of difficulty 4 in Logic that seem stupidly easy, rarely are. (emphasis added)
re: This seems stupidly easy...
