4 doors to hell riddle

If he asked all the stones, in order, which way would lead him to salvation, the correct answer would come up in an alternating pattern, wouldn't it? i.e.

stone 1 (lying) says door three
stone 2 (truth) says door five
stone 3 (lying) says door one
stone 4 (truth) says door five
stone 5 (lying) says door four.

No, the person doesn't know the order of the stones so it can be that 2 alternate stones are lying.

Please explain this statement: "No, the person doesn't know the order of the stones so it can be that 2 alternate stones are lying." It seems to contradict the problem statement.

A flaw in Numbnut's solution is if the the responses are:
door 1
door 2
door 1
door 2
door 1
you can't tell if the correct door is 1 or 2.

Depending on your explanation, at most four questions will be required.

For N = 1 to 4
Ask stone N, "will stone N+1 say door N leads to safety?"

When the response is no, the door in question leads to safety. If no "no" response is received, then door 5 leads to safety.

The answer is the person should ignore the stones and simply exit from the door he used to enter the room

markr the hamsters a running amok

"markr the hamsters a running amok"

huh?

Oops. "A flaw in Numbnut's solution" should be "A flaw in Francisco's solution."

Numbnut isn't nuts for sure :wink:

now I get it - thanks for clearing that up for me guys :-D

Does he ask the stones yes/no questions? By not being able to ask direct questions he would have to ask indirect questions. What would constitute as an indirect question? There are too many logical holes in this riddle.



sum1

he should start with #2 and ask
"if i ask the stone before you which door leads to death, what will he tell me?"
the lier stones will lie about how the truth stone will answer, ans since only one door leads to saftey, it will be the same number.
the truth tellers will tell the truth about the liars lieing and also saying the same number.

Why are you guys still trying to crack this question?

This was a twisted puzzle with basic idea that the person entered the room thru one door. Now he has 5 doors. Out of which 4 doors goto hell. So obviosuly the non-hell door in the one he entered in thru. He should simply exit from the door he used to enter the room. Ignore the bloody stones

Vinsan,

The riddle says he entered a room. It doesn't state that he entered a room through a door. Maybe he entered through a window. Maybe he jumped from a plane and crashed through the ceiling. Who knows. If the original poster will ever bother to answer my question, the answer will most likely become obvious, but the way the riddle is written right now, I can't tell.


If anyone here has any idea what would constitute as an indirect question, please tell me. I never knew there was a difference between a direct and indirect questions. I never knew either/or existed.

sum1

The original poster already said the answer. I assume that means that the questions you asked are irrelevant.

Then the poster might want to reword the riddle, because logic would lead a person to consider the possibility that the person could have entered through another way besides a door.


sum1

Even though this topic has been dead for a couple of months, I'm new, and I have an actual answer for this one that's better than "go through the door you came in."

start with the first stone, ask "what would the stone to the right of you tell me is the safe door?" If it is a liar, it will answer with a dangerous door number, because he would lie about what the truth teller would say. If it is a truthteller, it will still point you to a dangerous door, because that's what the liar would say.

(This is assuming the stones go truth-liar-truth-liar, or vice versa. If they're at random, you can just ask "What would the type of stone that is the opposite of what you are say?" and it should still work.)

Let's say that the stone said door 1, which now we know is unsafe.
Ask the second stone what the stone to the right of him would say is the safe door, door 2, 3, 4, or 5. This is important, because otherwise he could give you a repeat, and we already know that door 1 is unsafe. The same logic applies here as with the first stone, and the door it says will be unsafe.

Ask the third rock about the remaining 3 doors,
the fourth about the last 2,
and you're left with one safe door left.

So if anyone ever asks you this riddle again, and doesn't accept the "door you came in" answer, try this one.

Nice reply.
I started thinking about this and we don't actually know that the stones know about their relation to each other. We don't even know if they know anything about the doors.

Let's presume that they know this.
Doing it this way we would only need to ask maximum 3 stones:

To 1st stone: What would the stone after you tell me if I asked if I have a possibility of getting to safety by choosing one of the 3 first doors?
No means yes, yes means no. If the answer is yes, we will know the solution after asking the next stone. If the answer is no we might know the solution after the next time, or after asking the 3rd stone.

If answer was no:
To 2nd stone: What would the stone after you tell me if I asked if I have a possibility of getting to safety by choosing one of the 2 first doors?
If it says yes, we know the 3rd stone is safe.

If second answer was no:
To 3rd stone: What would the stone after you tell me if I asked if the first door will lead me to safety?
There are only two possibilities left and this answer will show if door number 1 or 2 is safe.

If you go to stone one and ask it will stone two tell you the truth.

If stone one is lying he will tell you that stone two will tell the truth

If stone one is truthfull then it will tell you stone two will lie.

you then know where you are in the sequence.

prints, you are completely wrong. Take another look at your logic.


Of course theres always the classic "what would you say if I asked you..." method, which would leave you with one rock left over to ask embarrassing and revealing questions to.