Menu
By:
Filters
What's new

Incredibly difficult logic problem.

I

input

Noob
Johnny San said:
The only way to prove this is by plugging it in to all possible combinations.
Liar - Truth - "Random" / Liar - "Random" - Truth / Truth - Liar - "Random" / Truth - "Random" - Liar / "Random" - Truth - Liar / "Random" - Liar - Truth.

Let's take this combination: Truth - "Random" - Liar with "Da" meaning "yes". Perfect situation and the first guard obviously says "Da" to the first question. You then ask the Liar his question. 1=1 and "Da" does mean "yes". He's a Liar so he'd say "Ba" meaning "no". You've figured the Liar and the Truth teller. Now you're left with the "Random". He can either say a truthful answer or a false one. Whether he says "Ba" or "Da" doesn't matter. You don't know if what he says is the truth.


You're asking them once multiple times. Against the rules.
Click to expand...
I don't know if that's the case but if it is then the description is throwing me off, because I might be interpreting it wrong. The OP states " Each guard will answer only one question. (You may pose up to three questions, one to each guard)" That could possibly mean what you either you or I trying to prove. Seems it could go either way really since there are no more details. Also another reason I was under this impression was because of this spoiler:

You only need to ask one question.
 
NRF CharlieMurphy

NRF CharlieMurphy

Kindergarten Meta
Johnny San said:
The only way to prove this is by plugging it in to all possible combinations.
Liar - Truth - "Random" / Liar - "Random" - Truth / Truth - Liar - "Random" / Truth - "Random" - Liar / "Random" - Truth - Liar / "Random" - Liar - Truth.

Let's take this combination: Truth - "Random" - Liar with "Da" meaning "yes". Perfect situation and the first guard obviously says "Da" to the first question. You then ask the Liar his question. 1=1 and "Da" does mean "yes". He's a Liar so he'd say "Ba" meaning "no". You've figured the Liar and the Truth teller. Now you're left with the "Random". He can either say a truthful answer or a false one. Whether he says "Ba" or "Da" doesn't matter. You don't know if what he says is the truth.
Click to expand...
sure you can..... my final question was actually wrong.... because I didn't stipulate the same thing as the first question.
Since now you KNOW what "ba" and "da" mean...... you can ask the last guy the "Will this road lead me to the riches if and only if "ba" means yes and the 2nd guard is random"
Since you KNOW the 2nd guard is random (deduced before hand) and that "ba" is yes... he'll give you the answer.
 
Johnny San

Johnny San

Shazzy's Biggest Fan
NRF CharlieMurphy said:
snip
Click to expand...
I read your first point as if you were asking if "Da" meant yes if you were a truthful person.
But that still doesn't solve the problem. If you asked the "Random" if riches were on the wrong path and he decided to give the false answer of "yes" it would contradict the statement. And what if only one of the original conditions was met in your first question. If the first guard was telling the truth, he'd have to give a random answer since it would be impossible to answer.

I don't think this works. And there's still the need to see if this works for all other combinations.
 
Groove Heaven

Groove Heaven

Jobber-baron
Oh Christ this thing.

I was a philosophy major and this came up in logic class. I couldn't figure it out on my own, shit is hard and it involves a lot of logic. Like...you need a pencil and paper, and the questions you ask won't be simple.
 
Pan1cMode

Pan1cMode

AUS FGC represent!
Just a hint, the answer has been posted in this thread, but the person who answered didn't know they posted a solution :).

9.95 said:
@NRF CharlieMurphy snip
Click to expand...
The problem is your first question breaks down under different conditions.

Scenario; Da = Yes
Truth will answer "Ba(no). Ba doesn't mean yes"
Liar will answer "Da(yes). Ba means yes"

Therefore this question doesn't deduce anything meaningful as an answer of Ba or Da doesn't indicate whether or not they equal yes or no.
 
Last edited:
The Highlander

The Highlander

There can be only one
Pan1cMode said:
Just a hint, the answer has been posted in this thread, but the person who answered didn't know they posted a solution :).


The problem is your first question breaks down under different conditions.

Scenario; Da = Yes
Truth will answer "Ba(no). Ba doesn't mean yes"
Liar will answer "Da(yes). Ba means no"

Therefore this question doesn't deduce anything meaningful as an answer of Ba or Da doesn't indicate whether or not they equal yes or no.
Click to expand...
Haha, interesting... I knew they were overcomplicating it. Thanks for posting this btw, I love these type of things even if I suck at them.
 
Pan1cMode

Pan1cMode

AUS FGC represent!
NRF CharlieMurphy said:
So if I asked the first guard....
"Does da mean yes if and only if you tell the truth and the 2nd guard speaks randomly?"

If he answers da... then... I know that the 3rd Guard is Either one of the Truth/Liar and that the 2nd Guard speaks random
If he answers ba... then ... I know that the 2nd Guard is either one of the truth/liar and the 3rd guard speaks random.

Now I simply can go to the guard i've deduced as the truth/liar and ask the simple question "Does da mean yes if 1 equals 1?"

If he answers da, then I know he is the truth.
If he answer ba, then i know he is the liar.

ask the last guard "Will the first path lead me to the riches?"

edit: the first question is worded weird... but i'm pretty sure that it flawlessly tells me which guard is random even if the guard i asked is random... could be wrong tho :(
@Pan1cMode
Click to expand...
Nice logic, but what if the first question is posed to random? You cannot deduce the identity of random from your question. Only the identity of someone who is not random.

Also, by the end of your second question, you have deduced whether or not a certain guard is a truth teller, but not the meaning of Da and Ba. Your last question would be fruitless because it wouldn't yield a meaningful result.
 
roosTakk

roosTakk

Chode Juggler
9.95 said:
@NRF CharlieMurphy is correct in his thinking here. You don't get to the answer by asking which path leads to where. You get to the answer by:

1. Deducing what ba and da mean.
2. Deducing which guard is the random


The last thing you have to remember is that "random" doesn't mean giving random answers. "Random" means that for each question, that guard's mind is either "liar" or "truth"(50/50 coin flip for each question asked of the random guard). That means that in order to deduce the correct answer from the random, you have to ask about the guard's MINDSET AT THAT MOMENT in a multi-tiered question that has a condition that you know to already be correct. Based on his answer (assuming you have deduced the meaning of ba and da), you can determine if the mindset of the random guard AT THE MOMENT OF THE QUESTION was liar or truth.

For the point of this answer, lets assume that the guards will say Ba for Yes and Da for No. (We don't know this yet, but we will as we ask questions)

You need to ask multi-tiered questions where both conditions must be met in order to get a "yes" answer from the truthful guard.
You MUST assume that any of the guards could be the random, so you must incorporate the the above "random stipulation" (noted in yellow) to all questions.



Go to G1:
Hold up 1 finger and ask:
"At the moment of this question, Does Ba mean yes, if and only if I am holding up one finger?"
-"Ba" - The guard has met both conditions of the question. = Truth or Random
-"Da" - The truthful answer to this question is Ba(because you KNOW you're holding up 1 finger already), so the lying guard will respond with Da. = Lying or Random
-In both scenarios, you have now deduced that Ba means Yes and Da means No.

Go to G2:
Now you need to root out the random guard so you know what to ask guard 3.
Hold up 1 finger and ask:
"At the moment of this question, Will G1 speak the truth, if and only if I am holding up one finger?" (Remember, we know that the truth teller MUST answer Ba to this question)
--If G1 answered "Ba"
----G2 answeres "Ba"
------- We have already deduced that G1 is either the truth or the random, so G2 is now deduced to be either truth or Random.
----------You may now freely ask G3 (who in turn MUST be the liar) if "X" path is safe to take and then immediately take the other path.
----G2 answers "Da":
------- We have already deduced that G1 is either the truth or the random, so G2 is now deduced to be either lying or Random
----------You can now question G3, who is EITHER truth or random with the following question:
------------"At the moment of this question, is "X" path safe to take, if and only if I am holding up one finger?" (Again, we KNOW we are holding up one finger, so a TRUTHFUL answer will be "Ba" and a lying answer will be "Da"). Based on the answer given, you take the appropriate path.
Click to expand...

..........no. and may god have mercy on your soul.

That was the most idiot thing I have read in a long time.
 
Last edited:
roosTakk

roosTakk

Chode Juggler
hint **

- One of the guards here will answer either truthfully or falsely but which is random.
- The guards understand English but they will reply in their own native tongue.
- It is known that Ba and Da mean yes and no in the guard's native language but which means which is unknown. One means yes and the other no.
- Each guard will answer only one question. (You may pose up to three questions, one to each guard)
- The guards know which direction leads to where and the identities of the other guards.
- Further clarification; the guards may only answer Da or Ba nothing else. They cannot gesture or point. If presented with a paradox or something unknowable they will answer randomly.
 
I

input

Noob
It seems I wrote everything wrong though after looking back at it.


Truth Liar Random
  1. yes yes yes
  2. no no no
  3. no no yes
  4. no yes yes
  5. yes no no
  6. yes yes no
  7. yes no yes
  8. no yes no

omit row 1,2,5,7.8 (1 and 2 because they can't all be the same answer. 5 because truther is saying yes and liar is saying opposite while random is saying no too. 7 and 8 because both the liar and the truth teller are saying opposites and the random is saying the same thing in their respective row .)

leave row: 3,4,6

row 3 is 2 no and 1 yes
row 4 is 1 no and 2 yes
row 6 is 1 no and 2 yes

and because both guards can't be yes, we omit row 4 and 6 and are left with row 3, which is 2 no and 1 yes. So you can pick either ba or da for yes or no from the beginning and I believe it works out the same way in the end.

(2 ba or no) and (1 da or yes)
or
(2 da or no) and (1 ba or yes)

and

(2 da or yes) and (1 ba or no)
or
(2 ba or yes) and (1 da or no)
 
Last edited:
You must log in or register to reply here.