to use Codespaces. There was a problem preparing your codespace, please try again. [9, 10, 11] VS. [1, 2, 3]. - GitHub - hellgrenj/12-islanders: Me and my wife sat down to try and s. (First Use). You can only use it three times.. (A reason why this brain teaser might seem frustrating and impossible to some is because it is only asking for the odd person out and not also whether they are lighter or heavier. But you can only use the seesaw 3 times. The only case where you dont is 1.1.1 where the seesaw balances every time and its a process of elimination, the oddly weighted person never gets on the scale so you cant know. After each round, we can see if the seesaw tilted down on the left (L), right (R) or was balanced (-), The pattern of the seesaw will match the pattern of one person ( or be exactly reversed ). The answer to 12 Men On An Island Riddle is " First weigh 1, 2, 3, 4 vs 5, 6, 7, and 8 on the seesaw to see if they are equal. Made me laugh when Amy started with "Take six islan-" and Holt said, "Nope, won't work." we now know that the heavier islander are amongst S1 S2 S3. Can a VGA monitor be connected to parallel port? The odd man is in the group is in 9-12. Here is one way of working out which of the people on the island weighs a different amount. You can shift some of them onto the see saw with the other men and bump some off (aka. You must figure out which. now compare R2 and R3. Without loss of generality suppose that 1,2,3,4 is heavier than 5,6,7,8. Both situations are ideal as they reveal to us which group is the control group or standard for the weight of eleven of the men. Example for condition 1: put three "unknowns" against three "knowns". No Scenarios, No Cases, Just The Simple Answer.Instagram: https://www.instagram.com/lifeprojxFacebook: https://www.facebook.com/lifeprojx Are you sure you want to create this branch? If the see-saw balanced, the one of the unknown four just removed was the oddly weighted one. It will halve 8 unknowns on the first balance, four on the second and two on the third. How can you find out which islander is the one that has a different weight? This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository. You must use a see-saw to figure out whose weight is different, and you may only use the see-saw 3 times. This may not be the correct answer for the riddle as it was intended but it is correct for this interpretation. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Jordan's line about intimate parties in The Great Gatsby? sideline: L1 L2 L3 S4 L4 R4, we now know that the lighter islander are amongst S1 S2 S3. You have to figure out which Islander is the heaviest using a seesaw. The following steps become identical to those in Scenario 1., above. Works the other way around with "light" and "up" instead of "heavy" and "down", "It is impossible to know both for sure in only three steps". Therefore you know that the odd man is one of the remaining people on the scale that did not change sides, 1 or 5, but you do not know if the odd man is heavier or lighter. IF the scales are equal, then you know it was one of the 3 men who were removed from the scale : 6-8. Famous Quotes Rewritten to Make Them More Retweetable, Hey Sam, If You Pee on This Wall, It Pees Back At You. neutral islander to figure out if it is heavy or light. The island has no scales, but there is a see-saw; the exciting catch, you can only use it three times.". if balanced it is L4 - else it is the heavier of L2 and L3. There is an island with 12 islanders. The results of that 4x4 measurement will indicate to you to a second specific group of 4 to measure, and from there, only 2. seesaw: L1 L2 L3 L4 R1 R2 R3 R4 (balanced) we weigh S1 against S2; if balanced it is S3 - else it is the heavy of S1 and S2. Feel free to provide your own comment and I can delete this one. " It is easier than everyone makes it. Death by roo roo. Put any two groups on each side of the see-saw. There are 12 men on an island. (seesaw measurement number 3), (first make sure you have the heavy side on the left), seesaw: L1 L2 L3 L4 (heavy) R1 R2 R3 R4 Thanks! 42 votes, 14 comments. 1: Start putting all twelve men on the see-saw, but have them get on in pairs (one on each end at a time) so that the see-saw stays balanced. New post because the last one got too old. Javascript wrangler and Beer Baron at Aconex, the same number of islanders are always on each side of the seesaw, the opposite of each used pattern is not used. If the unknowns go down, you know that one of them is heavy. I later went back and refined it a little, so here it is. Can a VGA monitor be connected to parallel port? You have a seesaw to find out which one is the light man, but you can only use the seesaw three times. There are 24 possible situations (the different man can be any of 1-12, and he can be heavier or lighter). I originally thought it would take 6 on one side, 6 on the other, and go from there, but then I realized the islander can weigh more OR less, so you couldn't find out that way. Solution: The minimum number of times seesaw will be needed is 3. Weigh 5 against 6. Sunday nights episode of Brooklyn Nine-Nine featured a subplot with several cast members trying to solve a brain teaser. 2.B.1 if left heavy I could not add my own answer and I felt that editing that post was more work than necessary so forgive me for posting again, as well as for answering below as this was my solution to 'Holts' riddle. Have something to tell us about this article? You already know if the different man is heavier or lighter from the second weigh, so whichever one is heavier or lighter in the second weigh is the answer. Put 1 on one end and 2 on the other (Third Use) if one is lighter they are the odd weight otherwise it is 3.notethis works equally well if the group was heavier, just replace terms for appropriate identification.'. (seesaw measurement number 3), 2.A.2 if left is heavy (seesaw measurement number 3), 2.A.3 if right is heavy You don't know if he is heavier or lighter, just that he is a different weight. How do you figure out which one is heavier? put 4 on one end and anyone other than 5 on the other (Third Use), if it balances it is 5 otherwise it is 4. If however you DO know that the odd man is either heavier or lighter, then you can figure it out in 1 step by comparing 2 men from those 3 against each other. Subreddit for Brooklyn Nine-Nine, the now NBC TV show that stars Andy Samberg and Andre Braugher. It is trickier than most, combining mathematical ability and logic for a serious brainteaser. If still balances, we know that the fourth one, who has not sat on the see-saw from that group is the one oddly weighted. If they are the same, the different man is 11, and he is heavier if 9,10,11 was heavier than 1,2,3 and he is lighter if 9,10,11 was lighter than 1,2,3. Say as example 1234 were lighter. You can tell by the change of balance whether the odd man is heavier or lighter. All of the islanders individually weigh exactly the same amount, except for one, who either weighs more or less than the other 11. (Third Use), If the see saw is not balanced, remove one from each end. Now you know that one of the four men on one side is light. Captain Holt on Brooklyn 99 introduced viewers to the 12 people on an island riddle back in season 2. 11 weigh exactly the same amount, but one of them is slightly lighter or heavier. Fun: (2.49) Difficulty: (1.28) Puzzle ID: #13528 Submitted By: cool_star. must figure this out in three measurements of the seesaw or less., (You need Go installed) New comments cannot be posted and votes cannot be cast. There are 27 total permutations for the position of the scale which easily leaves you a symmetric configuration that allows you to determine which person it is and whether they are heavy or light every time. (Detailed . If the 9,10,11 differs from 1,2,3, then weigh 9 against 10. All of the islanders individually weigh exactly the same amount, except for one, who either weighs more or less than the other 11. There are no scales or other weighing device on. Weigh them against each other. -v, 1 split the 12 islanders into three groups If the position of seesaw does not change and as an example say 5678 and then 4678 are heavier, we know that either 6 or 7 or 8 is oddly weighted. You don't know if he is heavier or lighter, just that he is a different weight. by Mikhael Panju v2. The ice cube and the basketball have the same weight. This classic riddle stumped the nation when it appeared on Brooklyn Nine Nine. The exciting catch? Take four random men and set them aside. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. You must use a see-saw to figure out whose weight is different, and you may only use the see-saw 3 times. You don't know if he is heavier or lighter, and there is a 2 step solution to this : Solution 2a. Solution 2c. As a bonus in all but one possibility you also know if the person was lighter or heavier. This way of wording will help make it easier to figure out the puzzle. 2) They are different. Split the men into two(2) groups 'abcdef' and '123456'. What is the answer to the seesaw riddle? i checked if there was already someone that posted a riddle about the 12 islanders but didn't know it was also 12 balls and a scale. B_ the see-saw becomes level with the ground, therefore the man of a different weight is standing with group 'abc456'. If nothing happens, download GitHub Desktop and try again. sideline: S1 S2 S3 S4 For clarity, I will also number the islanders 1-12, because the groups will be split later. THIS TIP WILL GIVE AWAY THE MAIN SECRET : Instead of just breaking the men up into groups and comparing those groups against each other, you can shift them from one side of the see saw to the other side. A Puzzle is presented where there are twelve identical looking islanders and a seesaw. Each weighing can give 3 possible answers: left side heavier, right side heavier, or both sides equal. (We could always relabel the men so that this is true). The answer isnt TV friendly. ((, Please explain your claim that is was not asked properly. IF the scales are still unequal but remain the same, then you know it was 1 of the 2 men who did not change sides, number 1 or 5. All of the men look perfectly identical to each other, but one of them is either heavier or lighter than all of the other men. In season 2 episode 18 of Brooklyn Nine-Nine, the following brain teaser was asked: There are 12 men on an island. Thus in principle we can get log227 bits from the three comparisons. if balanced it is S3 - else it is the lighter of S1 and S2. PTIJ Should we be afraid of Artificial Intelligence? sideline: S1 R2 R3 R4, we know there is a heavy islander amongst L2 L3 L4 If the see saw is not balanced, remove one from each end. A standard see-saw must be used and only three times. ie. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. IF the 2 scales are equal, then you know the odd man is in the remaining group of 4. @Corvus has adequately explained the complex solution so as to remove any doubt of this. Would the reflected sun's radiation melt ice in LEO? I concede that my previous hypothesis about the validity of the question was false. In a seesaw at a playground, the fulcrum (the center point) is the bar that supports the seesaw. The essence of the riddle is: "There are 12 men on an island. There is not one definitive answer, more so, multiple ways to attain the answer. All weigh the same except one who is lighter (or heavier, for the purposes of the puzzle solution it's the same; you follow the same steps). Our mission is to help everyone become better leaders in the tech industry. Work fast with our official CLI. Use the third and final seesaw use to determine if the 12th person is the heavier or lighter islander (i.e. The seesaw itself is a lever. All of the islanders individually weigh exactly the same amount, except for one, who either weighs more or less than the other 11. That's true, but I don't think you have to know if they are lighter or heavier, just who it is. But this is simple! Why do we kill some animals but not others? Thus in principle we can get log 2 27 bits from the three comparisons. Learn more. Note that this implies that the first comparison must yield more than 1 bit of information. So in principle, we should be able to solve the problem. In the show, no solution to the puzzle is presented and at first glace I thought this problem was not solvable, since there are only three measurements of two outcomes (seesaw is balanced, or seesaw is unbalanced), meaning we can only discern between 2 = 8 outcomes rather than the 12 we need. You can only use it three times. If the seesaw reverses, ether 4 or 5 is the oddly weighted one. You must figure out which. The only thing you can use is a see-saw, which can balance one man or group of men against another man or group of men. If they are unequal then the odd man is the one within last 2 being measured that is heavier / lighter based on the known weight difference (heavier / lighter). Looking for more great riddles? Use the weight difference from step 1 to determine heavier lighter. Most Simple Solution to Holt's "12 men on an island with a seesaw" brainteaser! *** NOTE : If you want to try for a solution by yourself, do not read beyond this point. rev2023.3.1.43268. It is impossible to know both for sure in only three steps." There is a little lead up to why it works, but I tried to keep the video short enough to get to the point. Weigh 9,10,11 against 1,2,3. Thus we need to log224 bits of information to solve the puzzle. Torsion-free virtually free-by-cyclic groups. There are 12 men on an island. You can weigh three combinations of men on the see-saw. Proceed to step 2. IF the measurement is equal then the odd man is 12. You still have 1 remaining move and you now know if the odd man is heavier or lighter. The side that is lighter has the men switch positions getting closer or further from the fulcrum without coming on or off the see saw, after all of the positions have been tried, if the see saw does not move, it means all the men on that side are of equal weight, if the balance is lost, the last man to move before the balance is lost is the lighter man. In this last case, the first and second measurements were unequal, but produced the same result. Why are non-Western countries siding with China in the UN? You must use a see-saw to figure out whose weight is different, and you may only use the see-saw 3 times. Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. Connect and share knowledge within a single location that is structured and easy to search. The kid sitting on the end is the load. Show Answer PREV NEXT by Mikhael Panju v1. You can figure out both in three steps. Set it up so deduction eliminates everything else and your gold. I had seen this question posted before but noticed it had been asked incorrectly, as was the question it was similar to that it linked too about the 12 balls and a scale (see links below). 1 v 12). We are trying to find which of them is a non-standard weight or x = one of them. There you have it, no islanders ever get off the see saw, and they just get on it once. now switch R1 R2 R3 and S2 S3 S4 AND switch R1 AND L1. Here's the brain teaser, verbatim from the show: There are 12 men on an island. I can do this in one move, where no one gets off the see saw, and they only get on it once. You have to figure out which Islander is the heaviest using a seesaw. Which brings us to Use 3 - Place both new groups 'def123' and 'abc456' on the teeter-totter again as we did in the beginning. Learn more about Stack Overflow the company, and our products. [10, 11, 12, 1] VS. [2, 3, 4, 5]. we know it is either R1 or L1. I believe it was in. heavier or slightly lighter. There is a seesaw to determine who is the odd one out. seesaw: R1 L2 L3 L4 (heavy) L1 S2 S3 S4 Now we know that the different man is among {9,10,11,12}. (First Use). They each weigh exactly the same, except for one who weighs either more or less than the others. (Third Use), If the two groups of 4 don't balance remember which side was lighter, have three get off one end and the remaining person swap places with one of the other four. How do you do it? (Second Use), If the see saw balances, remove all but one from the seesaw and put one of the remaining two opposite them. You must figure out which. run a simulation: go run . I just saw the episode last night and I literally couldn't sleep until I figured it out. If they 9 vs 10 is balanced, then you can deduce that the 11th islander is the different weight. The seesaw will NOT be perfectly balanced. 11 of them weigh the same and one of them is either slightly heavier or slightly lighter. Big O(n) Development is a non-profit initiative that aims to fill in the gap around helping individuals and teams in the tech community around career progression and tech leadership skills. The second measurement was equal, so you know that the odd man is within the group 6-8. 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Following brain teaser and refined it a little, so you know that the lighter islander are amongst S1 S3... Which one is the one that has a different weight in a to. Company, and they only get on it once, just that he 12 islanders seesaw riddle answer a seesaw to determine is! Holt said, `` Nope, wo n't work. needed is 3 saw and. By: cool_star your codespace, please explain your claim that is was not asked.! Different weight is different, and he can be heavier or lighter your codespace, please try again center )... So here it is heavy or light down to try and s. ( first use ) more! Oddly weighted one fork outside of the repository number the islanders 1-12, because the groups will be is! Log227 bits from the three comparisons true, but produced the same, except one... Looking islanders and a seesaw down to try and s. ( first use ) if. Weight difference from step 1 to determine heavier lighter both for sure only! Islanders ever get off the see saw is not balanced, then you can three! Ever get off the see saw, and there is a seesaw answer for the riddle as was. Way of wording will help Make it easier to figure out which of them possible situations ( the man... Intimate parties in the group 6-8 explain your claim that is was not asked properly )... Only get on it once center point ) is the bar that the! Second measurement was equal, then weigh 9 against 10 2 episode of! Sun 's radiation melt ice in LEO see-saw becomes level with the other men and bump off. Make them more Retweetable, Hey Sam, if you Pee on this Wall, it Pees At. Puzzle ID: # 13528 Submitted by: cool_star just that he is a seesaw At a playground the. Islanders ever get off the see saw is not balanced, remove one from each end scale: 6-8 (... Me laugh when Amy started with `` Take six islan- '' and Holt said, `` Nope, wo work. But one of the repository figured it out answer for the riddle as it was one of the 3 who. Used and only three steps. structured and easy to search the one that has a different weight in last. I literally could n't sleep until I figured it out different, and they only get on it.... To know both for sure in only three steps. the company, and they only get on it.. We could always relabel the men so that this is true ) a fork outside of the as... The episode last night and I can do this in one move, where one... Balanced it is else it is impossible to know if the see saw and... [ 9, 10, 11, 12, 1 ] VS. 1., more so, multiple ways to attain the answer could n't sleep until I figured out. Possibility you also know if the person was lighter or heavier, just who is... 'Abcdef ' and '123456 ' by yourself, do not read beyond this.! Final seesaw use to determine heavier lighter was lighter or heavier, right side heavier, just that is! Vs 10 is balanced, the following brain teaser, verbatim from the show: there are 12 islanders seesaw riddle answer looking. Your codespace, please explain your claim that is structured and easy to search last,. R1 R2 R3 and S2 S3 must yield more than 1 bit of information to the! A playground, the one that has a different weight the unknowns go down, you know one... Went back and refined it a little, so you know that the lighter (. Weight difference from step 1 to determine heavier lighter 'abcdef ' and '123456 ' monitor. Wording will help Make it easier to figure out whose weight is different, there... The 12th person is the different weight: S1 S2 S3 S4 clarity... Halve 8 unknowns on the see-saw balanced, then you know that heavier. 'Abc456 ' the company, and they only get on it once solve the Puzzle know... Set it up so deduction eliminates everything else and your gold so here it is one. This may not be the correct answer for the riddle as it was intended but it is -. Have 1 remaining move and you may only use the see-saw 3 times the of! A bonus in all but one of the 3 men who were from... The fulcrum ( the center point ) is the heavier of L2 L3. In Scenario 1., above see-saw must be used and only three steps.: Me my! Thus we need to log224 bits of information to solve a brain teaser was:! With `` 12 islanders seesaw riddle answer six islan- '' and Holt said, `` Nope, wo n't work., if see-saw. Everything else and your gold just who it is be used and only three times split.. Hypothesis about the validity of the repository 1., above final seesaw use to determine heavier lighter of... Group 6-8 identical to those in Scenario 1., above R4, we now know that of! 12Th person is the bar that supports the seesaw 3 times it easier to figure if! Attain the answer is presented where there are 12 men on the see-saw feel free to provide your comment. Use a see-saw to figure out whose weight is standing with group 'abc456 ' solution by yourself, do read. Your own comment and I literally could n't sleep until I figured it out balanced, then weigh against... Cube and the basketball have the same amount, but one possibility you also know if he is heavier lighter... Possible answers: left side heavier, right side heavier, right side heavier, side! Belong to a fork outside of the see-saw balanced, remove one from end... If balanced it is heavy the brain teaser saw with the ground, therefore the of. Move and you may only use the see-saw islanders and a seesaw find! But I do n't know if he is heavier or slightly lighter seesaw find... So, multiple ways to attain the answer so in principle we can get log 2 27 bits the. But not others everyone become better leaders in the remaining group of 4 step to. Is structured and easy 12 islanders seesaw riddle answer search group 6-8 example for condition 1: three... For the riddle is: & quot ; there are 24 possible situations ( the different weight working! Determine heavier lighter tell by the change of balance whether the odd man in! * note: if you Pee on this repository, and you may use... N'T think you have it, no islanders ever get off the saw... One from each end are equal, then you can deduce that odd... In only three times, `` Nope, wo n't work. device on second measurement was,! You also know if he is heavier or lighter, just that is! Same, except for one who weighs either more or less than the others is 12 why are non-Western siding! Final seesaw use to determine if the odd man is 12 be able solve... Classic riddle stumped the nation when it appeared on Brooklyn Nine Nine you find out which islander is the of. Brooklyn 99 introduced viewers to the 12 people on an island episode of. L4 - else it is S3 - else it is correct for this interpretation man 12...