Inthis TED - Ed brain-teaser , we explore a classical logical system puzzle invented by logician Raymond Smullyan . As the picture tells us , it has been call the hardest logical system teaser ever . They ’re not kidding .
So here ’s the post . You have clangoring - landed on a mystifying planet . The only way to escape is to appease three exotic overlords ( they were " gods " in the original telling , hence its name ) .
You acknowledge that the three aliens are named Tee , Eff , and Arr . There are also three artifacts on the planet , each of which matches a unmarried stranger ( for the sake of simpleness , let ’s assume they are labeled " Tee , " " Eff , " and " Arr " ) . To appease the aliens , you need to match up the artefact with their aliens — but you do n’t know which of the alien is which !
You are allowed to ask three yes - or - no questions , each addressed to any one alien . ( you’re able to call multiple question to the same alien , but you do n’t have to . )
To further complicate matter , each foreigner has a specific behavior with regard to state the truth . Tee ’s result are always true . Eff ’s answers are always false . Arr ’s solvent are random .
Yet another job is that while you know the foreign words " ozo " and " ulu " somehow correspond to " yes " and " no , " but you do n’t live which is which . ( I know , this situation just keeps get down worse ! ) So while you may communicate enough of the exotic language to ask questions , they will answer only with " ozo " or " ulu . " You may require the questions one at a prison term , make on each reply if you wish well — meaning you have clip to remember about the next interrogative sentence based on what you have learned .
So your labor is to call for three yes - or - no questions , while not knowing which answering words represent to " yes " and " no , " of three outlander whose identity is unknown , but whose behavior is predictable … if you knew their indistinguishability . How can you forecast out which alien is which , so you could pass on the right objects to the aliens ? Put your thinking caps on , then roll the video recording explanation ( which includes the solution , after a suitable break ):
For more on this puzzler , check out this TED - Ed page . For some flavor on logician Raymond Smullyan , check out his interview with Johnny Carson .
