Guest Posted November 7, 2008 Report Share Posted November 7, 2008 Alright, I think this is original but is not too difficult of a thought so it could have been made before, so I apologize if it is a repeat: A king, who always tells the truth, has four identical brothers: Two who always lies One who sometimes tells the truth and one who always says what the person on his right says The five brother are standing in a line and the last brother does have someone on his right. How many questions do you need to ask to determine who the king is, and what are the questions? Quote Link to comment Share on other sites More sharing options...
0 bonanova Posted November 7, 2008 Report Share Posted November 7, 2008 Alright, I think this is original but is not too difficult of a thought so it could have been made before, so I apologize if it is a repeat: A king, who always tells the truth, has four identical brothers: Two who always lies One who sometimes tells the truth and one who always says what the person on his right says The five brother are standing in a line and the last brother does have someone on his right. How many questions do you need to ask to determine who the king is, and what are the questions? Flesh that out a little ... In a line, which brother is the "last" brother? Or are you telling us that the "last" brother is the end brother who has the other four to his right? If so, does the "first" brother have anyone on his right? Or are you saying that the "first" brother has the other four brothers on his right, but the "last" brother has a sixth person, not a brother, on his right? Do the questions have to be Yes/No questions, or could they be of the type: "Please identify yourself, the king, the two liars, the unknown speaker and the copy-cat."? Sounds like an interesting puzzle, just need to know the rules. Thanks. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 7, 2008 Report Share Posted November 7, 2008 (edited) "one who always says what the person on his right says" This brother does have someone on his right, he does not say nothing. That is all the line, and that statement meant. Basically, he copies one person. I realized when I typed it there may be some ambiguity in typing "last." Also, you can ask any question you would like to ask. Hope that helps. Edited November 7, 2008 by RyanJ Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 7, 2008 Report Share Posted November 7, 2008 Two questions. These questions will be completely exclusive in order to find the liar. 1. Show them an orange ball, or an object with a distinct color. Ask them that color. Repeat the process the 2nd time with a different color ( for the sometimes guy) This will induce the answer. 1. The two liars will obviously tell the wrong color, if they don't then they are truth speakers which of course be a paradox and void that statement. 2. The guy who lies sometimes will or may tell the truth the first tme but lie the second, if he doesn't he is again a truth seaker. 3. Then the guy who repeats everything to his right will have the same answer as the truth seaker or the liar. This guy is easy to spot. 4. Of course the guy who get's all the colors right ( and is to the right of guy #4 is the king. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 7, 2008 Report Share Posted November 7, 2008 You need to ask two questions. Ask everyone "Is the person to your left the king" and then ask everyone "Is the person to your right the king". Only the king will be able to truthfully say "no" to both questions and therefore you can identify which one he is. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 7, 2008 Report Share Posted November 7, 2008 I can think of less questions than everyone so far. Remember a question to everyone is five questions, because it has five distinct answers; if that makes sense to you. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 7, 2008 Report Share Posted November 7, 2008 A question to RyanJ - does the "One who sometimes tells the truth" tell the truth and lie absolutely randomly or by turns (truth - lie - truth - lie - etc.)? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 8, 2008 Report Share Posted November 8, 2008 I think smokiecat's got it Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 8, 2008 Report Share Posted November 8, 2008 Show two balls to the most right person and ask their colours - if you get two correct answers, this person must be the King. If both of the answers are wrong, this must be a liar. Ask him: "who is NOT the King?" and he should point at the King. If one answer is wrong and the other one correct, you must be talking to the brother, who sometimes tells the truth and sometimes lies - I assume he does it in order truth-lie-truth or lie-truth-lie. If he started with the correct answer, ask him "Who is the King?", if he started with the wrong answer, ask him "Who is not the King?". Quote Link to comment Share on other sites More sharing options...
0 bonanova Posted November 9, 2008 Report Share Posted November 9, 2008 You need to ask two questions. Ask everyone "Is the person to your left the king" and then ask everyone "Is the person to your right the king". Only the king will be able to truthfully say "no" to both questions and therefore you can identify which one he is. Does the "first" brother have anyone on his left? Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 9, 2008 Report Share Posted November 9, 2008 Can't we just assume that the brothers are standing in a circle? That way every person has someone on his left and on his right. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 10, 2008 Report Share Posted November 10, 2008 Can't we just assume that the brothers are standing in a circle? That way every person has someone on his left and on his right. do what you want; and the brother that sometimes tells the truth and sometimes lies, does it absolutely randomly. There are shorter answers than the ones named, though no one is even close to the correct answer...maybe that is a little hint. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 10, 2008 Report Share Posted November 10, 2008 A king, who always tells the truth, has four identical brothers: Is the king also identical to the four brothers? If not, then the king would be the one who does not look like the others Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 10, 2008 Report Share Posted November 10, 2008 (edited) Is the king also identical to the four brothers? If not, then the king would be the one who does not look like the others ha, that is the REAL answer. It is simply a semantics issue that most people confuse. If I have two identical coins, they are not identical to me, yet each other. The same with having four identical brothers. Though, I figured some may be upset so if you want to assume the king is identical to the brothers, I have thought up a few solutions. Think similar to the original versions of these problems, but warning, the work is long for you have to look at a number of scenarios... Edited November 10, 2008 by RyanJ Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 12, 2008 Report Share Posted November 12, 2008 ha, that is the REAL answer. It is simply a semantics issue that most people confuse. If I have two identical coins, they are not identical to me, yet each other. The same with having four identical brothers. Though, I figured some may be upset so if you want to assume the king is identical to the brothers, I have thought up a few solutions. Think similar to the original versions of these problems, but warning, the work is long for you have to look at a number of scenarios... This is similar to a puzzle from critical thinking class. Except there was no semantics answer. Ionno had the right idea. Ask a question you, and the individual being asked know the answer to. By doing so, you can: a. find out who's telling the truth and ask them "who is the king?" b. find out who's lying and ask them in the negative, "who is NOT the king?" Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 12, 2008 Report Share Posted November 12, 2008 (edited) --FORGETTING ABOUT SEMANTICS-- But what if the other brothers can't tell each other apart? Each person would know whether or not they are the King, but may not be able to say for certain who the King is. And since the "Sometimes Liar" does so at random, he potentially could answer multiple questions correctly. Also, we know that the person who repeats what the brother to the right of him says has to be in position 1-4 because he does have someone to his right. Ideally, he would be to the left of a liar, but that may not always be the case. I feel that each question asked to one person counts as a question, so "2" cannot be the correct answer. Also, since multiple layouts exist, and we are looking to be absolutely certain who the King is, we must first identify the "Worst Possible Scenario" for identifying the King and ask questions from that setup. Without thinking about it too much, I feel that the worst case scenario would have the "copy cat" to the right of the "uncertain", and the placement of the other three unimportant. An example would be Liar-King-Copycat-Uncertain-Liar. EDIT: Typo Edited November 12, 2008 by Mumbles140 Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 12, 2008 Report Share Posted November 12, 2008 First off, I can't give an exact number, and you'll see why soon enough. Second, my assume 'layout' is Liar-King-Copycat-Uncertain-Liar. Begin by asking all 5 brothers a simple question--Are you the alive? You will instantly knock out the 2 liars. Assuming the Uncertain tells the truth, that leaves only three: King--Copycat--Uncertain. From here, only 3 remain. You have to ask obvious questions (i.e. what color is this ball, do you have 4 brothers, etc) until the Uncertain tells a lie. This will immediately identify the Liar and the Copycat, but since the Uncertain could potentially lie everytime but 1, no absolute number can be given. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 13, 2008 Report Share Posted November 13, 2008 First off, I can't give an exact number, and you'll see why soon enough. Second, my assume 'layout' is Liar-King-Copycat-Uncertain-Liar. Begin by asking all 5 brothers a simple question--Are you the alive? You will instantly knock out the 2 liars. Assuming the Uncertain tells the truth, that leaves only three: King--Copycat--Uncertain. From here, only 3 remain. You have to ask obvious questions (i.e. what color is this ball, do you have 4 brothers, etc) until the Uncertain tells a lie. This will immediately identify the Liar and the Copycat, but since the Uncertain could potentially lie everytime but 1, no absolute number can be given. I think you guys may be getting on the wrong track. The quicker way, is to ask "what would the person on your right say if I asked them if they were alive." Work from there. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 14, 2008 Report Share Posted November 14, 2008 I think you guys may be getting on the wrong track. The quicker way, is to ask "what would the person on your right say if I asked them if they were alive." Work from there. starting at the brother on the absolute left, ask him "what would the person on your right say if i asked them if they were alive?" Then, ask the person to his right "are you alive?" to see if the one before him was lying. then ask that same brother "what would the person on your right say if i asked them if they were alive?" etc. until you can tell who is lying or telling the truth. although, the number of questions you would have to ask would vary depending on the order of the siblings. what smokiecat said: ask all of them if the king is to their left, and then if the king is to their right. the only problem is the person who sometimes lies and sometimes tells the truth might tell the truth both times (assuming the king is not on either side of him) which would mean you would have to ask further questions to detmermine who the king is. so if there is an easier way than those two, i cannot think of it. Quote Link to comment Share on other sites More sharing options...
0 Guest Posted November 14, 2008 Report Share Posted November 14, 2008 what smokiecat said: ask all of them if the king is to their left, and then if the king is to their right. the only problem is the person who sometimes lies and sometimes tells the truth might tell the truth both times (assuming the king is not on either side of him) which would mean you would have to ask further questions to detmermine who the king is. so if there is an easier way than those two, i cannot think of it.starting at the brother on the absolute left, ask him "what would the person on your right say if i asked them if they were alive?" Then, ask the person to his right "are you alive?" to see if the one before him was lying. then ask that same brother "what would the person on your right say if i asked them if they were alive?" etc. until you can tell who is lying or telling the truth. although, the number of questions you would have to ask would vary depending on the order of the siblings. getting closer....what would happen if I asked the king who always says the truth what the person who sometimes said the truth would say...this should a help thought upon a number of scenarios. On Monday, I will probably reveal my solution to the shortest number of Q's...though there may be a quicker one. Quote Link to comment Share on other sites More sharing options...
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Alright, I think this is original but is not too difficult of a thought so it could have been made before, so I apologize if it is a repeat:
A king, who always tells the truth, has four identical brothers:
Two who always lies
One who sometimes tells the truth
and one who always says what the person on his right says
The five brother are standing in a line and the last brother does have someone on his right.
How many questions do you need to ask to determine who the king is, and what are the questions?
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