One day you wake up in a strange room with no windows and three exits (don't ask why, you just do). Between you and the doors is a very moody looking guard who will no doubt kick your ass if you try to mess with him in any way. Suffice it to say, you're a bit put out by all this nonsense and want to get home in time for dinner. You ask the guard how to get home and, gesturing toward the doors, he replies:
One of these leads to salvation,
the other two lead to damnation.
Three questions you will get to try,
but be forewarned, on two I'll lie.
Don't ask why, for I just will,
You'll have to use your wits and skill.
Hmmm...okaaay. You've certainly had better starts to the day than this. What three questions can you ask what will guarantee your safe return home.
Edit: Forgot to add, they have to be yes/no questions.
Second edit: First off, apologies for neglecting this thread. I've been on a countryside break these past few days and decided to use the time to 'unplug', so to speak. I've read through the answers and, while NH and Mike Earnest together managed to get the answer I had in mind, pretty much all the answers presented are, IMO, actually better than mine. It never even occurred to me that this could be solved in only two questions! Anyway, just for the record, here's the answer I had in mind:
Will you answer this question with a 'Yes'? - This forces the guard to answer truthfully. His next two answers will definitely be lies.
2) Is door 1 safe? - If the guard says no, that means door 1 is safe so choose that one. If he says yes, you know it's dangerous.
3) Is door 2 safe? - If the guard says no, choose it. If he says yes again, that means both doors 1 and 2 are dangerous and so by elimination door 3 has to be the safe door.
Hope you had fun with this one. I'll try to make the next one a bit tougher :-)