Prisoners five through nine are each looking for an odd number of black hats.

Prisoner hat riddle ted ed answer.

The key is to minimize the time wasted by the two slowest people by having them cross together. But she only sees one so she deduces that her hat is also black. Lensko cetus ncs release musi. You and nine other individuals have been captured by super intelligent alien overlords. Youtube ted ed if you like brain teasers we ve got a doozy for you. Can you solve this hat riddle.

Alex gendler shows how. Prisoner four hears that and knows that she should be looking for an even number of black hats since one was behind her. Prisoners five through nine are each looking for an odd number of black hats. The prisoners and hats puzzle is a classic logic problem with many variants some of which are described and summarized here like other puzzles where each player has information about the other players but not about themselves they rely on inductive logic and the hierarchy of beliefs to figure out the other players thought processes to deduce the missing information. The aliens think humans look quite tasty but their civilization forbids eating highly logical and cooperative beings. Prisoner three sees an even number of black hats so he knows that his must be one of the black hats the first two prisoners saw.

Prisoner two also sees an odd number of black hats so she knows hers is white and answers correctly. Prisoners hat hard riddle can you solve it. Prisoner three sees an even number of black hats so he knows that his must be one of the black hats the first two prisoners saw. In this ted ed lesson alex gendler walks us through the prisoner hat riddle a classic puzzle. This puzzle is an excellent example of creative thinking in math. Unfortunately they re not sure whether you qualify so they decide to give you all a test.

And because you ll need to make a couple of return trips with the lantern you ll want to have the fastest people available to do so. Try the buried treasure riddle. You re a bank robber trying to escape from jail. Can you solve the riddle to get past the fence to freedom your timing made you and your partner infamous b. Prisoner four hears that and knows that she should be looking for an even number of black hats since one was behind her. So you and the lab assistant quickly run across with the lantern though you have to slow down a bit to match her pace.

But she only sees one so she deduces that her hat is also black. The origin of this puzzle is the 100 prisoners problem first published in 2003 by danish computer scientist peter bro miltersen the educator for this lesson first came across the puzzle at the gathering for gardner conference. At first it might seem like no matter what you do you re just a minute or two short of time but there is a way. Brain teasers and answer riddles and puzzles by genius test music. After two minutes both.