4 doors to hell....

Blaze · Posted: Sat May 20, 2006 2:50 am Post subject: 4 doors to hell....

Ok this is a hard one, i hope Very Happy

A man enters a room, the room contains 5 doors. 4 of these doors when opened will suck him into to hell to his certain death while 1 door will lead him to safety. There are also 5 rocks laid in a straight line with numbers 1 through to 5 on them. These are special rocks because they can talk, but they will either tell complete lies or be completely truthfull. He may only ask each rock 1 question each, but it must be in order from 1 to 5 (if he asked number 4 he cant ask number 1, 2 or 3) And to make it more wierder if a rock tells lies the rock after it must tell the truth. the only catch to this is that he cant ask them questions like 1 + 1 = ?? to find out if they lie or not.
How does the man get out of the room safely???

GameMaster · Site Regular Joined: 20 Apr 2006 Posts: 55

"And to make it more wierder if a rock tells lies the rock after it must tell the truth. "
Do we get to know if the reverse also true.

Blaze · Posted: Sun May 21, 2006 9:13 am Post subject:

Yup, sorry i forgot to tell to you, if one tells the truth the next has to lie Very Happy

outsider · New Member Joined: 21 May 2006 Posts: 10

Shame on you!

You left me thinking for 1 1/2 hours Sad

outsider · New Member Joined: 21 May 2006 Posts: 10

We ask the first stone: "Is it door 1, 2 or 3 a door to heaven?"
We ask stone2: "Did the first stone tell the truth?"
We ask stone3: "Did the first stone tell the truth?" (again)

If we had started with a true stone, from s2 and s3 we would have gotten the answers No and Yes respectively.
If we had started with a lier stone, from s2 and s3 we would have gotten the answers Yes and No respectively.

This way we can determine whether the door to heaven is in the first 3 or in the last 2. Also we now know if s4 and s5 will lie or tell the truth.

Lets assume that the good door is in the first 3. We ask stone number 4 and 5: "Is door nr1/nr2 the door to heaven?". This way we either eliminate 2 doors out of three or the stones tell us what door heaven is. Of course, if s4 is a lier we should be careful to interpret a Yes as a No and vice versa.

If the good door was behind d4 or d5 its the same but we need only 1 stone to ask.

Nice riddle but rather long and repetitive answer to say it to my friends. Smile

GameMaster · Site Regular Joined: 20 Apr 2006 Posts: 55

'We ask the first stone: "Is it door 1, 2 or 3 a door to heaven?"
We ask stone2: "Did the first stone tell the truth?"
We ask stone3: "Did the first stone tell the truth?" (again)

If we had started with a true stone, from s2 and s3 we would have gotten the answers No and Yes respectively.
If we had started with a lier stone, from s2 and s3 we would have gotten the answers Yes and No respectively."

ERr, you've learned nothing.
If the door is in the first three, and you start with truth teller:
yes, no, yes.
If the door isn't in the first three, and you start with a liar:
yes, no, yes.

Likewise, if it's not in the first three, and you start with a truth teller your looking at:
no, yes, no
If it's in the first three and you start with a liar, your looking at
yes, no, yes

Your test is in conclusive.

"This way we can determine whether the door to heaven is in the first 3 or in the last 2."
No, you havent -- see above.

"Also we now know if s4 and s5 will lie or tell the truth."
No, but we do know that s4 and s5 are complimentory and contain a lie.... Smile

"Lets assume that the good door is in the first 3. We ask stone number 4 and 5: 'Is door nr1/nr2 the door to heaven?'. This way we either eliminate 2 doors out of three or the stones tell us what door heaven is. Of course, if s4 is a lier we should be careful to interpret a Yes as a No and vice versa."
We don't know if it is or not.

"If the good door was behind d4 or d5 its the same but we need only 1 stone to ask."

THE ANSWER:
Alright... Here's how it works, it's a larger version of the Labyrith problem.

Ask Stome One "Would Stone two tell me the first door leads to heaven?"
Case 1: Stone One is lieing, Stone Two telling the truth, the first door leads to heaven.
Two would say it leads to heaven
One would say that Two would say it leads to hell
- It leads to heaven

Case 2: Stone One is lieing, Stone Two is telling the truth, the first door leads to hell
Two would say it leads to hell
One would way that Two would say it leads to heaven
- It leads to hell.

Case 3: Stone One is telling the truth, Stone Two is lieing, the first door leads to heaven
Two would say it leads to hell
One would say Two would say it leads to hell
- It leads to heave.

Case 4: Stone One is telling the truth, Stone Two is lieing, the first door leads to hell
Two would say it leads to heaven
One would say that Two would say it leads to heaven
- It leads to hell.

Either way, the lie is built in, if Stone One says that the other would say it leads to heaven, then move on to stone two door two, asking about what Stone three would say about door 2. Only on one door will a rock say that the next rock would say that it is the one that leads to hell, and that will be the door to heaven.

deryk · Guy Who Comes A Lot Joined: 19 May 2006 Posts: 159

why not just exit the same door u came in through?

GameMaster · Site Regular Joined: 20 Apr 2006 Posts: 55

dyrek, While against the spirit of the ridde, your solution would seem to work... Unless your path back was blocked or you were also trying to go somewhere in particular. I picked up "door to heaven" from the post before mine, but rereading the riddle, out the way you came seems like a "safe" way out.

Unclever title · Posted: Mon May 22, 2006 11:46 am Post subject:

Unless, of course, you just escaped from hell.

Blaze · Posted: Mon May 22, 2006 12:08 pm Post subject:

Yup you got it right Deryk, the riddle doesnt say that you need to go through the "correct" door it just asks how would you get out of the room safely, so the sensible thing to do would be to ignore the rocks and leave the room the way you came in....... Sorry for everyone that spent hours trying to figure it out with all that maths stuff Very Happy

deryk · Guy Who Comes A Lot Joined: 19 May 2006 Posts: 159

yay i got one! i think gamemaster's answer works too, incase u did escape hell by entering the room. then of course there are only 3 doors that lead u to hell and one that leads u to safety which would make the riddle a lot easier.

GameMaster · Site Regular Joined: 20 Apr 2006 Posts: 55

I'd like to point out, my way also works, though a bit more time consuming. Smile