Guys,
I came across this logic question tonight and was wondering if anyone has a viable answer.
There are two different machines from two different locations. One machine is from China and one is from Malaysia. If asked a question, the one from China will respond blue for correct and yellow for incorrect, while the one from Malaysia responds yellow for correct and blue for incorrect. What ONE question can be asked to both machines to derive their location?
Any help will be appreciated.
Thanks
“Are you in France?” - The one that responds yellow is in China, the one that responds blue is in Malaysia.
I’m sorry I got the question wrong. You are not given the colors a country will show when responding to a question that is correct or incorrect. I knew it wasn’t that easy…hopefully.
What? You are not given what colors? You mean you don’t know beforehand which country responds how?
Watch this video for a very closely related problem, the logic should be the same:
I hope this is right…
“If I asked the other machine whether it was in China, would it respond with ‘blue’?”
If blue = China’s yes:
Machine in China: Blue
Machine in Malaysia: Yellow
If yellow = China’s yes:
Machine in China: Blue
Machine in Malaysia: Yellow
The machine that answers ‘blue’ is always in China, and the machine that answers ‘yellow’ is always in Malaysia.
It seems like a variation of the liar/truthteller problem.
(Sorry mods, reposting… I somehow managed to delete the wrong post on the wrong message board entirely.)
I think I’ve got it
Ask them “does either machine signal blue to mean “yes” when asked if it is from China?” The one that signals blue is from China.
If you know that one of them will signal blue to mean yes and one of them is from China then you also know they will both have to answer yes to this question in their respective ways. The robot signalling blue therefore is signalling “yes”. You know that the statement “one robot will signal blue to mean “yes” when asked if it is from China” is true. A robot signalling blue is therefore saying both that it means “yes” and that it is from China.
Damn, I see the guy above beat me to it. Oh well…
Ha, looks like I beat you to forum username as well.
Watch the doorknockers from Labrynth. Problem is is old.