One morning you wake up to find yourself in a large room with three exits and no apparent entrance (don’t ask why, you just do). You don’t remember how you managed to get in there but suffice to say you are in there now and want to get home in time for dinner. You look at the three exits and note that they are all completely identical but are numbered 1, 2 and 3.
You also notice a rather menacing looking guard standing in your way, blocking your path to the doors. Naturally, you inquire as to which door to take. The guard replies
“One of these doors 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 have had better starts to the day than this. Still, you’ve got to play the cards you’re dealt. Which three questions will ensure you safe passage to the outside world?
Does this count as the first question? If it is, how can you be sure if the subsequent verse is the truth? Maybe all three dorrs lead to salvation! Or not.
The subsequent verse is the truth. Your first inquiry did not count as one of your questions. Woolly. I don’t understand how your solution works. Let’s assume it’s door one and the guard answers your questions thusly:
Q1 Does door #1 lead to salvation? - YES (truth)
Q2 Do I have 2 questions left? - NO (lie)
Q3 Does door #2 lead to salvation? - YES (lie)
How would you know whether or not to take door 1?
Wow, good work Beeblebrox. It’s totally different from the answer I’ve intended but I can’t spot a flaw in your solution so full credit goes to you. For the record, my answer was:
Q1: Will you answer this question truthfully
Q2: Does door 1 lead to salvation
Q3: Does door 2 lead to salvation?
Whatever the guard answers for Q1 will be a truthful answer. Therefore the answers to Q2 & Q3 are both lies. If the guard answers No to Q2 then door 1 is correct, if the guard answers Yes to Q2 but No to Q3 then door 2 is right and if he answers Yes to both 2 & 3 then door 3 is right.