The best answers are voted up and rise to the top, Not the answer you're looking for? Why do we kill some animals but not others? Thanks! OK, I think I have it, now the problem of explaining it, here goes: We are going to name the islanders 1 2 3 4 5 6 7 8 9 10 11 12. We know {9,10,11,12} all weigh the same. The first measurement of 4 vs. 4 was equal. heavier or slightly lighter. I later went back and refined it a little, so here it is. 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. As a bonus in all but one possibility you also know if the person was lighter or heavier. 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). Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. 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 ). I like Rosa's answer squeeze until fatty confesses. Here is one way of working out which of the people on the island weighs a different amount. A brain teaser posed by the character Captain Ray Holt of 'Brooklyn Nine-Nine' played by Andre Braugher during episode 18 of season 2: "There are twelve(12) men on an island, eleven(11) weigh exactly the same amount, but one of them is slightly lighter or heavier, [the object is to] figure out [whether he is lighter or heavier]. Say as example 1234 were lighter. You can weigh three combinations of men on the see-saw. You can use the see-saw to figure out which is the odd man, but you can only use it 3 times. Weigh them against each other. You must figure out which. Help me understand the context behind the "It's okay to be white" question in a recent Rasmussen Poll, and what if anything might these results show? Find out the minimum number of times the seesaw will be used. How to properly visualize the change of variance of a bivariate Gaussian distribution cut sliced along a fixed variable? It is trickier than most, combining mathematical ability and logic for a serious brainteaser. c) If they are the same, then one of 3,4 is different. It is impossible to know both for sure in only three steps.). Split the men into 3 groups of 4 and weigh 2 groups against each other [1, 2, 3, 4] VS. [5, 6, 7, 8]. Take note of whether it is heavier or lighter. This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository. Jordan's line about intimate parties in The Great Gatsby? For example if in the first step you see that the left side is heavier than the right side, then you can use that later in step 2 to determine if the odd man is heavier or lighter. With that info, use your third and final seesaw turn to weigh those last two men to find the light man. Applications of super-mathematics to non-super mathematics. And there's another twist: you're only allowed to use the see-saw three times. Set it up so deduction eliminates everything else and your gold. (Third Use), If the see saw is not balanced, remove one from each end. Thus in principle we can get log227 bits from the three comparisons. If the weights are equal, then one of A2.4 is heavier; weigh A2 and A3. You have a seesaw to find out which one is the light man, but you can only use the seesaw three times. seesaw: R1 L2 L3 L4 L1 S2 S3 S4 (balanced) If they are equal, it is the remaining man not being measured. Bottom line? There is also a see-saw on the island. :D, Brooklyn 99 riddle: Weighing Islanders [duplicate]. Thanks, AeJey for making it so clear! If he is lighter then it is the one being measured and he is lighter. You must figure out which. seesaw: S1 S2 S3 R1 R2 R3 (heavy) So in principle, we should be able to solve the problem. You must use a see-saw to figure out whose weight is different, and you may only use the see-saw 3 times. The island has no escapes, but there is a seesaw. The best answers are voted up and rise to the top, Not the answer you're looking for? Before that I didnt really get what you were doing. Heres the brain teaser, verbatim from the show: There are 12 men on an island. The seesaw will balance perfectly. 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. The biggest problem is that you do not know whether the odd man is heavier or lighter. Just forget about them for a few minutes. Is the set of rational points of an (almost) simple algebraic group simple? Proceed to step 2. If they are the same, 8 is the one we are looking for (and lighter). 12 Islanders Riddle Puzzle from Brooklyn 99. You must use a see-saw to figure out whose weight is different, and you may only use the see-saw 3 times. test all the cases: go test . Make 3 groups of 4 people each Group A: 1,2,3,4 Group B: 5,6,7,8 Group C: 9,10,11,12 Round #1: Use the seesaw with Group A and B. Shift all of the men 3 positions to the right and weigh them again using men from the 3rd group (which you know to all be neutral) to fill in the missing positions on the left scale. [9, 10, 11] VS. [1, 2, 3]. You have to figure out which Islander is the heaviest using a seesaw. Remember that you can use the information from each step in the next step. Before you read on, I just want to say that this problem drove me nuts. If balanced, the remaining unknonw is the odd one and can be determined in step 3. (Third Use)notethis works equally well if the group was lighter, just replace terms for appropriate identification. now compare L2 and L3. L: sit on the left, R: sit on the right, -: dont sit on the seesaw. You have a seesaw to determine who is the odd one out but you It is of indeterminate length I wish for my see saw to be long enough to place 12 on either side, but only six will be on either side of the fulcrum. Logic Logic puzzles require you to think. There are no scales or other weighing device on. sideline: L1 L2 L3 S4 L4 R4 In season 2 episode 18 of Brooklyn Nine-Nine, the following brain teaser was asked: There are 12 men on an island. Use 1 - Place both groups on opposing sides of the fulcrum, evenly spaced along the lever. If not balanced, the one going down is heavy. sideline: S1 R2 R3 R4, we know there is a heavy islander amongst L2 L3 L4 The exciting catch? Number the men 1,2,312. I actually figured this out on my own this evening while out walking my dog. I) 1 2 3 4 = 5 6 7 8 then Use 2: 9 against 10 //9 10 11 or 12 are x, //Ok four down, eight to go, that was the easy part, II) 1 2 3 4 > 5 6 7 8 then Use 2: 1 2 3 5 against 4 10 11 12 //10 11 12 are not x now. 2150 Condos - West Tower Phase 2 Connect and share knowledge within a single location that is structured and easy to search. First weigh 1,2,3,4 against 5,6,7,8. There is also a see-saw on the island. Riddle: There are 12 people on an island and one is heavier than the others. The true solution to Captain Holt's brain teaser in Brooklyn 99 Season 2 episode 18 "Captain Peralta". You can only use it three times.. 11 of them weigh the same and one of them is either slightly heavier or slightly lighter. {{#media.media_details}} {{#media.focal_point}}, First weigh 1, 2, 3, 4 vs 5, 6, 7, 8 on the seesaw. 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. Please You cant solve this puzzle? seesaw: R1 L2 L3 L4 L1 S2 S3 S4 (heavy) If the seesaw reverses, ether 4 or 5 is the oddly weighted one. Use 2 - Remove six(6) men from the see-saw, three(3) from both groups. Problem solved. Fun: (2.49) Difficulty: (1.28) Puzzle ID: #13528 Submitted By: cool_star. 42 votes, 14 comments. New post because the last one got too old. It is a good write up though. (Second Use). Eleven weigh exactly the same amount, but one of them is slightly lighter or heavier. a) If 1,2,5,6,7 is heavier, then either 1 or 2 heavier, or 8 is lighter. The riddle: There are 12 islanders on an island. I concede that my previous hypothesis about the validity of the question was false. You must figure out which. And there you have it! 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. You can only use it three times. 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". Otherwise the one who stayed is the oddly weighted one. 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. Comparing (1,2,3,4) to (5,6,7,8) does exactly this. Why are non-Western countries siding with China in the UN? IF the measurement is equal then the odd man is 12. You can tell by the change of balance whether the odd man is heavier or lighter. 2.B.1 if left heavy In that case, take two people from that group and place them on one end of see-saw and two of the balanced eight on the other. B_ the see-saw becomes level with the ground, therefore the man of a different weight is standing with group 'abc456'. Proceed to solution 1a. if balanced it is S3 - else it is the lighter of S1 and S2. The exciting catch? If they are equal then Weigh 9, 10, 11 vs 1, 2, 3. Solution 2b. I wonder if this is the highest-viewed duplicate question of all time? rev2023.3.1.43268. If the seesaw reverses, ether 4 or 5 is the oddly weighted one. 12 men live on an island. 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. Start off by weighing 4 against 4, setting the other 4 aside completely. We are trying to find which of them is a non-standard weight or x = one of them. Your aim is to find out which person weighs a different amount. A seesaw is binary. The unique and extremely popular [citation needed] authority on pop culture since 2008. now compare R2 and R3. - GitHub - hellgrenj/12-islanders: Me and my wife sat down to try and s. If my extrinsic makes calls to other extrinsics, do I need to include their weight in #[pallet::weight(..)]? At this point we just weight S4 against a Three measurements in all. You will have to be logical in your reasoning. No Scenarios, No Cases, Just The Simple Answer.Instagram: https://www.instagram.com/lifeprojxFacebook: https://www.facebook.com/lifeprojx Torsion-free virtually free-by-cyclic groups. Your aim is to find out which person weighs a different amount. There are 2 possible outcomes, either they are equal, or unequal. run a simulation: go run . There are 12 men on an island. put A&B on the seesaw then put A&C ( 2 uses) logic will give you the answer. You must figure out which. Questions: The side that rises will "scootch" down the length of the see saw, away from the fulcrum until both sides balance. It only takes a minute to sign up. New comments cannot be posted and votes cannot be cast. If one is heavier they are the odd one otherwise it is 6. That person is the heavier (or lighter). Was Galileo expecting to see so many stars? You cannot determine lighter, heavier, proceed to solution 2c. Are you sure you want to create this branch? must figure this out in three measurements of the seesaw or less., (You need Go installed) If the right side of the scale was heavier in step 1 then you know the odd man was heavier, and vice versa if it was lighter. Each islander is given a position to sit on the seesaw for each round. @emdee - Here is the link that you posted in the question. Take four random men and set them aside. Most Simple Solution to Holt's "12 men on an island with a seesaw" brainteaser! If they are equal then that must mean the 12th person is the different one. In other news,did Pete Davidson tattoo a kid? sign in The pattern for all islanders is below: person: A B C . 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). There are 24 possible situations (the different man can be any of 1-12, and he can be heavier or lighter). Learn more about Stack Overflow the company, and our products. (seesaw measurement number 3), 2.A.3 if right is heavy So in principle, we should be able to solve the problem. Weigh 12 against 1 to find out whether 12 is heaver or lighter. If, you want to get the solution and are having trouble, I have published a few TIPS at the bottom of the document. If the seesaw balances we know that either 1 or 2 or 3 is oddly weighted. This gives you your man. (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. Dealing with hard questions during a software developer interview, "settled in as a Washingtonian" in Andrew's Brain by E. L. Doctorow. You signed in with another tab or window. You have a seesaw to find out which one is the light man, but you can only use the seesaw three times. If 9 and 10 are different, the different man is the lighter of the 9,10 comparison if 9,10,11 was lighter than 1,2,3, (and he is lighter); the different man is the heavier of the 9,10 comparison if 9,10,11 was heavier than 1,2,3 (and he is heavier). Weigh 9, 10, 11 vs 1, 2, 3. Feel free to provide your own comment and I can delete this one. " sideline: S1 R2 R3 R4, we know that the light islander is amongst R2 R3 R4 Create an account to follow your favorite communities and start taking part in conversations. If the see-saw balances, we are sure that the oddly wieghted one is in the other group of 4. 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. There are 12 men on an island. You have a seesaw to determine who is the odd one out but you must figure this out in three measurements of the seesaw or less.. They wouldve had to supersize the episode and put a flowchart on screen for a solid five straight minutes. ie. Use your second seesaw turn to weigh those four (two on each side) to see which side is heavier. If you found that the second group weigh was unequal, then weigh 9 vs 10. Otherwise the one who stayed is the oddly weighted one. Hope you all sleep well after reading this. There are no scales or other weighing device on the island. It is easier than everyone makes it. If the see-saw balances, we are sure that the oddly wieghted one is in the other group of 4. All of the islanders individually weigh exactly the same amount, except for one, who either weighs more or less than the other 11. Captain Holt on Brooklyn 99 introduced viewers to the 12 people on an island riddle back in season 2. If nothing happens, download Xcode and try again. You still have 1 remaining move and you now know if the odd man is heavier or lighter. [10, 11, 12, 1] VS. [2, 3, 4, 5]. Are you sure you want to create this branch? Is it possible to measure 1 kilogram of sugar? That's not true. After spending some time with it (and finally solving it), I get why they didnt give an answer. Now put 7 on one end and 8 on the other. Weigh A against B. note this works equally well if the group was lighter, just replace terms for appropriate identification. Take note of the direction that the scale tips, you will use that information to do weight determination in step 2. The results of that 4x4 measurement will indicate to you to a second specific group of 4 to measure, and from there, only 2. 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. 12 Islanders Teeter Totter Riddle There is an island with 12 islanders. The riddle, as you'll recall, is this: There are twelve men on an island. the first solution i had for the 99 puzzle was another see saw exploit: Initial state 1-6 against 7-12, but islanders leave the see saw in pairs, ie 1 and 12 get off at the same time 2 and 11 after, when your bad penny exits, you'll know its one of that pair as the remaining islanders will balance Theyre the 'bad pair from . (We could always relabel the men so that this is true). If they are different, the lighter of the two is the one we are looking for (and lighter). 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. The island has no escapes, but there is a seesaw. If they are equal then. New comments cannot be posted and votes cannot be cast. All of the islanders individually weigh exactly the same amount, except for one, who either weighs more or less than the other 11. 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.'. 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 this last case, the first and second measurements were unequal, but produced the same result. Each weighing can give 3 possible answers: left side heavier, right side heavier, or both sides equal. 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