How Can You Solve the 4 Doors to Hell Riddle?

[pallidin]

Here's my stab at it:

Q to Stone 1: Which door leads to heaven?
Q to Stone 2: Which door leads to heaven?
----
Now, at this point, I have established a 50/50 chance. Not bad.
So, my next step is to determine the sequencing(TFTFT or FTFTF)
----
Q to Stone 3: Which doors lead to Hell?
----

According to my tests on paper, here's what happens:
If the sequence is TFTFT, the STONE 3's answer will exclude one of the above previous stones numbers.
However, and this is interesting, if the hidden sequence is FTFTF, Stones 3's answer will include the same answer as the Stones 3 TFTFT answer!
-----
With that prize we now establish true sequencing through the next step:
Q to Stone 4: Which doors lead to Hell?
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If Stone 4's answer is different than Stone 3, the sequence is TFTFT.
If it is the same, it is FTFTF
----
At this point we do not even need Stone 5. Sequencing determines which of Stone's 1 and 2 answer is correct!


---- Why this works:
First, we force a 1/5 potential into a 1/2 potential(Through the Q's to Stones 1 and 2)

Second, we force Stone 3 to answer in exactly the same way regardless of its T/F status. This works because we switch the question from being "Which door leads to heaven to Which doors lead to Hell, KNOWING that the answer is dependent on Stone 2. This causes Stone's 3 answer to be the same, regardless of TFTFT or FTFTF.

Third, we force sequencing identity by asking the same question to Stone 4 as was asked of Stone 3.
Because of the "forced" inter-relationship of the previous stones, a same answer results in FTFTF and a different being TFTFT.
If Stone 4's answer is different than Stone 3, the door to heaven is given by Stone 1.
If Stone 4's answer is the same as Stone 3, the door to heaven is given by Stone 2.

Stone 5 is not needed.

 

[davee123]

Q to Stone 3: Which doors lead to Hell?

Ha! That's a good one! You only need one question!

If you ask stone #1 to name each of the doors that lead to hell:

1) If it's a truth telling door, it'll tell you FOUR doors, and the one that's missing will be the one to pick.
2) If it's a lying door, it'll tell you only ONE door, because otherwise it would be telling the TRUTH about SOME of the doors. And so the one to pick is the one that it names.

Nice!

DaveE

 

[juelz]

whats the answer?? its been half a month..tell us the answer a;lready!

 

[davee123]

whats the answer?? its been half a month..tell us the answer a;lready!

He posted his answer quite early on, actually (like two hours after the initial post)-- it was kinda silly:

Actually the answer is the person should ignore the stones and merely exit the room with the door he used to get to the room.

Note, he DID ask it on April Fools day!

DaveE

 

[Riddlenut1]

This riddle is simply easy. Just ask "What would stone #2 say if I asked him to name one door that was false?" Theory: Since it's a t/f pattern, if 1 was true then 2 was false. 2 would actually say the correct one since 2 is lying. If 1 was false and 2 was true, 2 would name a false door but since 1 lies then 1 will say the correct door. Either way, LET'S PARTY IS HEAVEN!

 

[ashishsinghal]

from each stone numbered n ask " is nth door the door to safety" when he gets consecutive yes or no he will get the right answer. If there are 3 consecutive yes/no then the middle one is the correct gate .ie if he gets answers nynnn then 4th door is the door to safety.

 

[Sybren]

Answer:

Ask each stone if the door corresponding to its number is the safe one.
The stone in front of the safe door can either lie to you, or tell the truth, which doesn't matter because...
The left and right neighbour of the 'safe-door stone' have to do the opposite: if the safe stone lies, the both have to tell the truth, and vice versa. The answers of these three stones will therefore be identical, since the doors neighbouring the safe one are dangerous.

From the list of replies, there will be three consecutive replies identical to each other. The middle one of these three belongs to the safe door.

Example:

safe door: +, dangerous door: -
case I: T,F,T,F,T; case II: F,T,F,T,F

suppose door #3 is safe. The replies will be either:
case I:-+++-
case II:+---+
In both cases the pattern of replies reveals that door #3 is the safe one.

[/color]

 

[tamtam402]

Edit: Wow nevermind, I'm dumb.