Author |
Topic: A Liar And A Thief (Read 1776 times) |
|
truemuffinman
Newbie
I am Ze Muffinman. PH34R
    
 
Gender: 
Posts: 39
|
 |
A Liar And A Thief
« on: Aug 22nd, 2006, 2:10pm » |
 Quote  Modify
|
You come to a fork in the road. You decide to take the road to the left, when you see a theif hiding behind a tree at the end. You immediatly turn back to go down the right road. You see a liar at the middle of the road, when he calls out to you. "There are three murderers down this road... I'd go the other way if I were you and lose your money rather then your life."
Things you know about the liar and the thieves:
- The liar has a very loose relationship with the murderers, meaning that they wouldn't kill him, and he wouldn't lie to them, but that's where it ends.
- The liar only lies 90% of the time; 10% of the time he tells the truth.
- The liar would not do you any harm if you pass him.
Things about yourself:
- You are semi-strong, meaning that you could probably take out one murderer, but not 3.
- Although you are pretty strong, thieves are extremely quick, meaning that he would steal from you before you had a chance to fight them.
Assume that:
- You must take either one road or the other, there are no shortcuts or alternative passages.
- You must do it righ there and then, you can't wait until they leave.
- You are carrying about $500, and a thief would steal ALL of it.
What would you do?
|
| « Last Edit: Aug 22nd, 2006, 2:11pm by truemuffinman » |
 IP Logged |
|
|
|
Three Hands
Uberpuzzler
Gender:
Posts: 715
|
|
Re: A Liar And A Thief
« Reply #1 on: Aug 22nd, 2006, 3:26pm » |
Quote Modify
|
Assuming that this is effectively forming the conundrum of "Down one route, you stand a 10% chance of death, but 90% of the time you are fine, meanwhile down the other route you are guaranteed to lose $500, which route do you take?", this is effectively asking whether you consider the utility of having an expected $450 or the utility of your life more worthwhile. Given I presume I have savings, or can alert police to the crime once I escape this situation alive, I would opt for the left road.
However, if I can get the "liar" to repeat his statement several times, through feigning deafness or some other ploy, I'd see what statement the liar adheres to most often is, and presume the opposite if there is suitable statistical likelihood.
|
|
IP Logged |
|
|
|
Icarus
wu::riddles Moderator
Uberpuzzler
Boldly going where even angels fear to tread.
Gender:
Posts: 4863
|
|
Re: A Liar And A Thief
« Reply #2 on: Aug 22nd, 2006, 4:11pm » |
Quote Modify
|
I go down the Thief road. There is a 10% chance that the thief road is better (based on the liar's second statement only). But even at 1% chance of death on the Liar road, the $500 just wouldn't be worth it. I value my life far more than that.
(And since I've already been down the Thief road to just shy of the end, I know that it is murderer-free.)
[e]Three-Hands hadn't replied when I opened this thread.[/e]
|
| « Last Edit: Aug 22nd, 2006, 4:16pm by Icarus » |
IP Logged |
"Pi goes on and on and on ...
And e is just as cursed.
I wonder: Which is larger
When their digits are reversed? " - Anonymous
|
|
|
towr
wu::riddles Moderator
Uberpuzzler
Some people are average, some are just mean.
Gender:
Posts: 13730
|
|
Re: A Liar And A Thief
« Reply #3 on: Aug 23rd, 2006, 12:45am » |
Quote Modify
|
Some murderers might well have crept up on the path behind the thief.
The liar says you'll get away with your life if you take that path, and there's a 90% chance he's lying. There's a ten percent chance there aren't 3 murderers on his road, but then, there might be 4 or twenty, or two or zero.
Basicly, you don't have any usefull information to make a decision, because there's always unfavorable interpretations. The only thing you can be sure of is that you'll loose $500 if you choose the thief side.
|
|
IP Logged |
Wikipedia, Google, Mathworld, Integer sequence DB
|
|
|
ezlonny
Newbie
Posts: 10
|
|
Re: A Liar And A Thief
« Reply #4 on: Aug 23rd, 2006, 2:35am » |
Quote Modify
|
What is that fork doing in the road. It might also have been a spoon or a knife?
|
|
IP Logged |
|
|
|
Weazel
Newbie
Gender:
Posts: 25
|
|
Re: A Liar And A Thief
« Reply #5 on: Aug 23rd, 2006, 10:12am » |
Quote Modify
|
Considering there's a 90% chance of him lying that the left side is safer, I'd take the right side. If I do happen accross a murderer, I'd beat him up, take him back to the liar, and force the liar to tell me the truth.
|
|
IP Logged |
|
|
|
truemuffinman
Newbie
I am Ze Muffinman. PH34R
Gender:
Posts: 39
|
|
Re: A Liar And A Thief
« Reply #6 on: Aug 23rd, 2006, 10:15am » |
Quote Modify
|
on Aug 23rd, 2006, 10:12am, Weazel wrote:| Considering there's a 90% chance of him lying that the left side is safer, I'd take the right side. If I do happen accross a murderer, I'd beat him up, take him back to the liar, and force the liar to tell me the truth. |
|
You forgot something.
"'There are three murderers down this road..."
"You are semi-strong, meaning that you could probably take out one murderer, but not 3. "
|
|
IP Logged |
|
|
|
truemuffinman
Newbie
I am Ze Muffinman. PH34R
Gender:
Posts: 39
|
|
Re: A Liar And A Thief
« Reply #7 on: Aug 23rd, 2006, 10:18am » |
Quote Modify
|
on Aug 22nd, 2006, 3:26pm, Three Hands wrote:Assuming that this is effectively forming the conundrum of "Down one route, you stand a 10% chance of death, but 90% of the time you are fine, meanwhile down the other route you are guaranteed to lose $500, which route do you take?", this is effectively asking whether you consider the utility of having an expected $450 or the utility of your life more worthwhile. Given I presume I have savings, or can alert police to the crime once I escape this situation alive, I would opt for the left road.
However, if I can get the "liar" to repeat his statement several times, through feigning deafness or some other ploy, I'd see what statement the liar adheres to most often is, and presume the opposite if there is suitable statistical likelihood. |
|
Assume that the liar never changes his lie too. xD
|
|
IP Logged |
|
|
|
truemuffinman
Newbie
I am Ze Muffinman. PH34R
Gender:
Posts: 39
|
|
Re: A Liar And A Thief
« Reply #8 on: Aug 23rd, 2006, 10:20am » |
Quote Modify
|
on Aug 23rd, 2006, 12:45am, towr wrote:Some murderers might well have crept up on the path behind the thief.
The liar says you'll get away with your life if you take that path, and there's a 90% chance he's lying. There's a ten percent chance there aren't 3 murderers on his road, but then, there might be 4 or twenty, or two or zero.
Basicly, you don't have any usefull information to make a decision, because there's always unfavorable interpretations. The only thing you can be sure of is that you'll loose $500 if you choose the thief side. |
|
Assume that the liar wasn't lying about that "safe road" part.
|
|
IP Logged |
|
|
|
Weazel
Newbie
Gender:
Posts: 25
|
|
Re: A Liar And A Thief
« Reply #9 on: Aug 23rd, 2006, 11:08am » |
Quote Modify
|
on Aug 23rd, 2006, 10:15am, truemuffinman wrote:
You forgot something.
"'There are three murderers down this road..."
"You are semi-strong, meaning that you could probably take out one murderer, but not 3. " |
|
Yes, but that's assuming
1. The liar was telling the truth about the number
and
2. The murderers are all together. In any case, since I have a keen enough eye to spot a thief, I would probably have a keen enough eye to spot three murderers and turn back before they get to me and go the other way.
|
| « Last Edit: Aug 23rd, 2006, 12:02pm by Weazel » |
IP Logged |
|
|
|
Sameer
Uberpuzzler
Pie = pi * e
Gender:
Posts: 1261
|
|
Re: A Liar And A Thief
« Reply #10 on: Aug 23rd, 2006, 11:38am » |
Quote Modify
|
I think this is an open puzzle with solution depending on person's choice.. the author may want to add more constraints or expand the puzzle to have one solution. I think!! 
|
|
IP Logged |
"Obvious" is the most dangerous word in mathematics.
--Bell, Eric Temple
Proof is an idol before which the mathematician tortures himself.
Sir Arthur Eddington, quoted in Bridges to Infinity
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: A Liar And A Thief
« Reply #11 on: Aug 24th, 2006, 12:05am » |
Quote Modify
|
Quote:- The liar has a very loose relationship with the murderers, meaning that they wouldn't kill him, and he wouldn't lie to them, but that's where it ends.
- Although you are pretty strong, thieves are extremely quick, meaning that he would steal from you before you had a chance to fight them.
|
|
Go and kill the thief. You'll get the money back after you had a chance to fight him. Being a murderer, the liar will stop lying to you.
Quote:- The liar only lies 90% of the time; 10% of the time he tells the truth.
|
|
The liar speaks 2 statements, both of them to the effect that the right road is deadly. Unless he told the truth twice, which happens 1% of the time, that road is safe.
Tell the liar you are taking the left road and take the right one. It makes you a liar. Hopefully, if there are murderes after all, they won't kill you.
|
|
IP Logged |
|
|
|
truemuffinman
Newbie
I am Ze Muffinman. PH34R
Gender:
Posts: 39
|
|
Re: A Liar And A Thief
« Reply #12 on: Aug 24th, 2006, 4:47pm » |
Quote Modify
|
on Aug 24th, 2006, 12:05am, Grimbal wrote:
Go and kill the thief. You'll get the money back after you had a chance to fight him. Being a murderer, the liar will stop lying to you.
The liar speaks 2 statements, both of them to the effect that the right road is deadly. Unless he told the truth twice, which happens 1% of the time, that road is safe.
Tell the liar you are taking the left road and take the right one. It makes you a liar. Hopefully, if there are murderes after all, they won't kill you.
|
|
Never thought of that. Good job!
|
|
IP Logged |
|
|
|
Roy42
Senior Riddler
Gender:
Posts: 418
|
|
Re: A Liar And A Thief
« Reply #13 on: Aug 25th, 2006, 8:04pm » |
Quote Modify
|
Sameer's right.
There are logical answers, then there are the personal answers, me, i choose the thief. Not just because i value my life more than $500, but i know an actual magic trick which will multiply the next one dollar i make from doing nothing into two, then into five, then into ten, then into twenty, 50, 100 250, 500, so on. Or i would call Legolas ( i call him leg less  )to check ahead on the liars path
|
|
IP Logged |
Regards,
≈Roy42
|
|
|
Sameer
Uberpuzzler
Pie = pi * e
Gender:
Posts: 1261
|
|
Re: A Liar And A Thief
« Reply #14 on: Aug 26th, 2006, 11:09am » |
Quote Modify
|
I like Grimbal's answers!!! especially the lying one.. least amount of work to fool everyone!!
|
|
IP Logged |
"Obvious" is the most dangerous word in mathematics.
--Bell, Eric Temple
Proof is an idol before which the mathematician tortures himself.
Sir Arthur Eddington, quoted in Bridges to Infinity
|
|
|
|
RIDDLES SITE
WRITE MATH!
Home 
Help 
Search 
Members 
Login 
Register
Reply
Notify of replies
Send Topic
Print