I remember this from the Labyrinth but where it falls down for me is that the computers (guards) have to know that one is truthful and the other lies which isn't pointed out in the riddle. If this is not assumed then it's pointless asking them the questions as neither would know how the other would respond.
Wate I think I totaly get it now. It does not matter witch one you ask because they will both tell you the bad door. sence one tells the truth it would say the bad door and sence the other lies it would say the bad door too.
I think anyway
I'm gonna trade this life for fortune and fame I'd even cut my hair and change my name
The logic of the question is flawed. Say you ask the lying computer, "What would the other computer say?" and it responds, "I do not have access to that information." How would you know if the response is true or not? You would have used up your 1 question and not gotten any answer you can use.