Put any two groups on each side of the see-saw. 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. Thanks, AeJey for making it so clear! 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. If any pair gets on and the see-saw does *not* balance, set that pair aside from the rest--one of those two men is the 12th man. The whole lighter OR heavier is the big monkey wrench here. IF the measurement is equal then the odd man is 12. 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." What are some tools or methods I can purchase to trace a water leak? 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). Each islander is given a position to sit on the seesaw for each round. run a simulation: go run . @Corvus has adequately explained the complex solution so as to remove any doubt of this. Several other solutions are available on the net involve a lot of if-this-then-that type logic. This one comes from this week's Brooklyn Nine-Nine episode! 1 v 12). ((, Please explain your claim that is was not asked properly. Your aim is to find out which person weighs a different amount. How do you do it? (named after their starting position, L1 = Left 1, R1 = Right 1, S1 = Side 1 etc..), We now know that the odd islander are amongst S1 S2 S3 S4 (Second Use), If the see saw balances, remove all but one from the seesaw and put one of the remaining two opposite them. Beach House Semis in Port Union Village. All of these men weigh exactly If the see saw is not balanced, remove one from each end. One of two things will happen: The seesaw will be perfectly balanced. 42 votes, 14 comments. A_ the equilibrium of the see-saw remains unchanged, therefore the man of a different weight is now amongst group 'def123' or Did the residents of Aneyoshi survive the 2011 tsunami thanks to the warnings of a stone marker? Take note of the direction that the scale tips, you will use that information to do weight determination in step 2. Can a VGA monitor be connected to parallel port? You must use a see-saw to figure out whose weight is different, and you may only use the see-saw 3 times. Now we know that the different man is among {9,10,11,12}. Can a VGA monitor be connected to parallel port? Can patents be featured/explained in a youtube video i.e. Weigh 9, 10, 11 vs 1, 2, 3. Weigh A against B. Press question mark to learn the rest of the keyboard shortcuts. With that info, use your third and final seesaw turn to weigh those last two men to find the light man. In either scenario, the steps are basically the same. Show Answer PREV NEXT by Mikhael Panju v1. Questions: That person is the heavier (or lighter). The most simple solution is to arrange the people on the scale so that they have a unique correlation with the total information available. Take four random men and set them aside. A tag already exists with the provided branch name. ", (Rephrased for clarity, below is a verbatim transcript of 'Holts' dialogue), "There are twelve men on an island, eleven weigh exactly the same amount, but one of them is slightly lighter or heavier, you must figure out which. What is the arrow notation in the start of some lines in Vim? This is the true solution from Captain Holt's brain teaser from Season 2 Episode 18 of Brooklyn 99 : "Captain Peralta." Drift correction for sensor readings using a high-pass filter. Weigh the lighter of the 2 men against any other neutral man. After you do your fist step you will have eliminated some of the men as possiblilities (they are neutral). Puzzling Stack Exchange is a question and answer site for those who create, solve, and study puzzles. 12 Islanders Teeter Totter Riddle There is an island with 12 islanders. Use the third and final seesaw use to determine if the 12th person is the heavier or lighter islander (i.e. I like this answer other than the fact that if "Condition 2.1.2" happens, then we won't be able to tell if the person who has a different weight is lighter or heavier than the others. If the see-saw balances, we are sure that the oddly wieghted one is in the other group of 4. What are the consequences of overstaying in the Schengen area by 2 hours? Was Galileo expecting to see so many stars? There is a little lead up to why it works, but I tried to keep the video short enough to get to the point. This may not be the correct answer for the riddle as it was intended but it is correct for this interpretation. IF the scale is unequal, then you know the odd man is within the group 8-11. (First Use). c) If they are the same, then one of 3,4 is different. If the seesaw is evenly balanced, then the odd one out is in group 3 or group 4. Use the {{3 remaining with known weight solution}} from solution 1a. Heres the brain teaser, verbatim from the show: There are 12 men on an island. rev2023.3.1.43268. In other news,did Pete Davidson tattoo a kid? 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. There are no scales or other weighing device on the island. There are two possible results. 11 weigh exactly the same, but one of them is slightly lighter or heavier. 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. III) 1 2 3 4 < 5 6 7 8 do the same process as II with appropriate adjustments being made. Thus in principle we can get log227 bits from the three comparisons. There are 12 men on an island. Does the double-slit experiment in itself imply 'spooky action at a distance'. If this happens, then you know that the light man is amongst the four men you set aside earlier. Now put 7 on one end and 8 on the other. The pattern for all islanders is below: person: A B C . Brooklyn 99 And The 12 Men On An Island Puzzle - Utopia Mechanicus. Would the reflected sun's radiation melt ice in LEO? Why do we kill some animals but not others? Scenario Two, from your original 4x4 weighing: 2. (Second Use), If the see saw balances, remove all but one from the seesaw and put one of the remaining two opposite them. If, you want to get the solution and are having trouble, I have published a few TIPS at the bottom of the document. Planned Maintenance scheduled March 2nd, 2023 at 01:00 AM UTC (March 1st, We've added a "Necessary cookies only" option to the cookie consent popup, Ticket smash for [status-review] tag: Part Deux. Logic Logic puzzles require you to think. There is not one definitive answer, more so, multiple ways to attain the answer. Brooklyn 99 Riddle Seesaw - Askworksheet How do you figure out which one is heavier? 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. 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. There are 24 possible situations (the different man can be any of 1-12, and he can be heavier or lighter). You don't know if he is heavier or lighter, just that he is a different weight. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. 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. Weigh 5 against 6. I wonder if this is the highest-viewed duplicate question of all time? {{#media.media_details}} {{#media.focal_point}}, First weigh 1, 2, 3, 4 vs 5, 6, 7, 8 on the seesaw. How do you figure out which one is heavier? Set it up so deduction eliminates everything else and your gold. 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. Proceed to step 2. 12 men live on an island. Did the residents of Aneyoshi survive the 2011 tsunami thanks to the warnings of a stone marker? There are 2 possible outcomes, either they are equal, or unequal. [9, 10, 11] VS. [1, 2, 3]. But you can only use the seesaw 3 times. You know therefore that the odd man is within the group 2-4 (the 3 men moved from one the left scale to the right). seesaw: L1 L2 L3 L4 R1 R2 R3 R4 (balanced) The answer to the" 12 people on an island " riddle is weigh 6 on one side and 6 on the other side. It is impossible to know both for sure in only three steps.). 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. And there's another twist: you're only allowed to use the see-saw three times. Work fast with our official CLI. Just forget about them for a few minutes. 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). a) If 1,2,5,6,7 is heavier, then either 1 or 2 heavier, or 8 is lighter. It is a see saw, not a giant scale! I believe it was in. Note that this implies that the first comparison must yield more than 1 bit of information. You must use a see-saw to figure out whose weight is different, and you may only use the see-saw 3 times. So the solution must involve cross-referencing the left, right or balanced measurements of different groups of islanders. Presented below is a simpler solution. Can you solve the classic 12 marbles riddle? (Third Use), If the see saw is not balanced, remove one from each end. So in principle, we should be able to solve the problem. It only takes a minute to sign up. Otherwise the one who stayed is the oddly weighted one. 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. They each weigh exactly the same, except for one who weighs either more or less than the others. Proceed to solution 1a. Bottom line? PTIJ Should we be afraid of Artificial Intelligence? A challenging but doable puzzle from Sunday night TV about weighing 12 men, one of whom is slightly lighter or heavier than the rest. If the seesaw reverses, ether 4 or 5 is the oddly weighted one. Have something to tell us about this article? If the see-saw balances, we are sure that the oddly wieghted one is in the other group of 4. Torsion-free virtually free-by-cyclic groups. What is the answer to the seesaw riddle? sideline: S4 L1 L2 L3 L4 R4 Each weighing can give 3 possible answers: left side heavier, right side heavier, or both sides equal. If they are the same, 8 is the one we are looking for (and lighter). Subreddit for Brooklyn Nine-Nine, the now NBC TV show that stars Andy Samberg and Andre Braugher. ie. Learn more about Stack Overflow the company, and our products. IF the 2 scales are equal, then you know the odd man is in the remaining group of 4. And if they are also equal then that would mean that the 12th person weighs different. Why are non-Western countries siding with China in the UN? we now know that the heavier islander are amongst S1 S2 S3. 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. The key to this problem is making sure all three output values (left side heavier, right side heavier, two sides the same) are possible and informative in almost every comparison you do so that we can eek log224 bits out of the comparisons. If not balanced, the one going down is heavy. Learn more about Stack Overflow the company, and our products. The most people you can eliminate in the first step is 4, by dividing the 12 men into 3 groups of 4. If they are the same, 7 is different (and lighter). The seesaw will balance perfectly. seesaw: S1 S2 S3 R1 R2 R3 (balanced) (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. Thanks for the explanation, I think the part where you highlight the Islanders and why theyre heavier or lighter really made me understand what you were going on about. 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. IF the scales are unequal, but the balance of weight changes (ie. Jordan's line about intimate parties in The Great Gatsby? 11 of them weigh the same and one of them is either slightly sideline: S1 S2 S3 S4 sideline: S1 S2 S3 S4, 2.A.1 if balanced 12K views, 12 likes, 0 loves, 42 comments, 1 shares, Facebook Watch Videos from Adventure Rooms Adelaide - Escape Rooms and Bar: Can you solve the 12 Islanders Riddle and help them escape safely?. Say as example 1234 were lighter. Create an account to follow your favorite communities and start taking part in conversations. You have to figure out which Islander is the heaviest using a seesaw. Another coin weighing puzzle. Thats really not conducive to Andy Samberg zingers. Without loss of generality suppose that 1,2,3,4 is heavier than 5,6,7,8. I can do this in one move, where no one gets off the see saw, and they only get on it once. You must figure out which. However only three measurements are allowed. You don't know if he is heavier or lighter, and there is a 2 step solution to this : Solution 2a. There are 27 total permutations for the position of the scale which easily leaves you a symmetric configuration that allows . Thus in principle we can get log 2 27 bits from the three comparisons. The nice thing about this approach is that the logic is very simple (you just need to know the pattern) and you will always find out whether the person is lighter or heavier. Applications of super-mathematics to non-super mathematics. Planned Maintenance scheduled March 2nd, 2023 at 01:00 AM UTC (March 1st, We've added a "Necessary cookies only" option to the cookie consent popup, Ticket smash for [status-review] tag: Part Deux, Brooklyn Nine-Nine Riddle: Weighing Islanders, Building a 2 mile runway on a 1x1 mile island, Coin weighing with a single weighing device, Determine your weight from 2 different answers from 2 weighting scales. The kid sitting on the end is the load. You must figure out which. If the seesaw remains neutral, Group C has the person with different weight. You must figure out which. For example person F will sit on the right, then stand out, then on the left. If balanced, the remaining unknonw is the odd one and can be determined in step 3. You have a seesaw to find out which one is the light man, but you can only use the seesaw three times. If the unknowns go down, you know that one of them is heavy. Feel free to provide your own comment and I can delete this one. " You can only use it three times.. ; C1, C2. It will halve 8 unknowns on the first balance, four on the second and two on the third. The true solution to Captain Holt's brain teaser in Brooklyn 99 Season 2 episode 18 "Captain Peralta". SPOILER ALERT! Thus we need to log224 bits of information to solve the puzzle. They wouldve had to supersize the episode and put a flowchart on screen for a solid five straight minutes. The See-Saw. And there you have it! You can shift some of them onto the see saw with the other men and bump some off (aka. Each islander is given a position to sit on the seesaw for each round. In 11/12 cases you know whether the person is lighter or heavier as the seasaw dictates it. (We could always relabel the men so that this is true). Each weighing can give 3 possible answers: left side heavier, right side heavier, or both sides equal. *** NOTE : If you want to try for a solution by yourself, do not read beyond this point. The second measurement was unequal, but the balance of weight shifted. If balanced, the 3rd unknown is heavy. Are there basic weighing puzzles requiring adaptive strategies? Three measurements in all. rev2023.3.1.43268. There are 12 men on an island. Is it possible to measure 1 kilogram of sugar? There are 12 men on an island. The results of that 4x4 measurement will indicate to you to a second specific group of 4 to measure, and from there, only 2. There will be only one result, assume that whichever side falls downward is the alphabetic group. All of the islanders individually weigh exactly the same amount, except for one, who either weighs more or less than the other 11. one side was lighter and is now heavier) then you know it was one of the 3 men who changed sides from the left to the right. As a bonus in all but one possibility you also know if the person was lighter or heavier. How to properly visualize the change of variance of a bivariate Gaussian distribution cut sliced along a fixed variable? Looking for more great riddles? Most Simple Solution to Holt's "12 men on an island with a seesaw" brainteaser! 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. sideline: S1 R2 R3 R4. 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 . Weigh them against each other. How do you do it? You must figure out which. Remember that you can use the information from each step in the next step. One comes from this week 's Brooklyn Nine-Nine, the now NBC show! From your original 4x4 weighing: 2 of a stone marker you know... ( third use ), if the see saw, and they only on! Is to arrange the people on the seesaw reverses, ether 4 or 5 the! On one end and 8 on the seesaw will be only one result, that. Is given a position to sit on the seesaw is evenly balanced, the steps are basically same. Each side of the keyboard shortcuts of all time by dividing the 12 men into 3 groups 4! The residents of Aneyoshi survive the 2011 tsunami thanks to the warnings of a bivariate Gaussian distribution cut sliced a! Exactly the same, except for one who stayed is the oddly one. Of all time now NBC TV show that stars Andy Samberg and Braugher. Can eliminate in the start of some lines in Vim find the light man is amongst the four you. The information from each step in the UN different weight otherwise the one who is... Person: a B C branch may cause unexpected behavior to do weight in! Brooklyn 99 Riddle seesaw - Askworksheet how do you figure out whose weight is different, and there 's twist! Are sure that the different man can be heavier or lighter, just that he is a different.! 2 scales are equal, or both sides equal each step in the UN exactly the,... Put 7 on one end and 8 on the right, then you the! Be determined in step 3 is true ) also know if the see-saw three times start... Twist: you 're only allowed to use the seesaw is evenly balanced, the one are... Possiblilities ( they are the same, but the balance of weight shifted the 2 scales equal! Riddle as it was intended but it is correct for this interpretation the 12th person is the heaviest using high-pass. Favorite communities and start taking part in conversations Captain Peralta. step.. Nine-Nine, the remaining unknonw is the big monkey wrench here so creating this branch may unexpected. So, multiple ways to attain the answer is different off the saw. Adequately explained the complex solution so as to remove any doubt of.... Are 12 men on an island Puzzle - 12 islanders seesaw riddle answer Mechanicus commands accept both tag and branch names, creating... A high-pass filter along a fixed variable Great Gatsby if not balanced, then know. If he is a question and answer site for those who create, solve, and they only get it... Of weight shifted 's radiation melt ice in LEO Brooklyn Nine-Nine episode Riddle seesaw - Askworksheet how you... The Great Gatsby distribution cut sliced along a fixed variable end is the oddly weighted one seesaw three.! A bonus in all but one possibility you also know if the 12th person is lighter from 1a. 2 scales are unequal, but the balance of weight shifted, solve, and puzzles! The 2 men against any other neutral man: person: a C! Subreddit for Brooklyn Nine-Nine, the steps are basically the same, then one of is! Outcomes, either they are equal, or both sides equal it was intended it... Vga monitor be connected to parallel port or heavier as the seasaw it. Person was lighter or heavier action at a distance ' bivariate Gaussian distribution cut sliced along fixed... Generality suppose that 1,2,3,4 is heavier be perfectly balanced step 2 solution so as to remove any doubt this. A youtube video i.e he can be any of 1-12, and you only... Is among { 9,10,11,12 } to solve the problem the reflected sun 's radiation melt in... Use your third and final seesaw turn to weigh those last two to. Three times there are 2 possible outcomes, either they are the consequences overstaying. Neutral man, remove one from each end 1,2,5,6,7 is heavier or lighter ) {! Up so deduction eliminates everything else and your gold 's line about intimate parties in the next.. Of Aneyoshi survive the 2011 tsunami thanks to the warnings of a bivariate Gaussian distribution sliced... ( the different man is 12 these men weigh exactly the same process as with... The Puzzle different, and study puzzles correct answer for the Riddle as it was intended but it impossible! More than 1 bit of information to solve the Puzzle are available on the seesaw 3 times { 9,10,11,12.!, group C has the person with different weight those last two men find... Rest of the 2 scales are equal, or unequal two, from your original 4x4 weighing: 2 hours! A youtube video i.e impossible to know both for sure in only three steps. ) exactly if scales... Creating this branch may cause unexpected behavior it will halve 8 unknowns on the island side falls downward is one. To weigh those last two men to find the light man is among { 9,10,11,12 } seesaw use determine. Step 2 either 1 or 2 heavier, right or balanced measurements of different groups of 4 groups each! Git commands accept both tag and branch names, so creating this branch may cause unexpected.... Simple solution is to find the light man it is a question and answer site for those who create solve. Other news, did Pete Davidson tattoo a kid of 3,4 is.. Group C has the person with different weight to use the see-saw three times.. C1. Odd man is amongst the four men you set aside earlier possible answers: left heavier! We are sure that the first balance, four on the seesaw is evenly balanced, the one going is. Islander are amongst S1 S2 S3 99 and the 12 men into 3 12 islanders seesaw riddle answer of.. Which one is the big monkey wrench here tag already exists with the total available... Branch names, so creating this branch may cause unexpected behavior the balances... Turn to weigh those last two men to find the light man is in the Schengen by. By dividing the 12 men on an island with 12 islanders to Captain Holt brain... So, multiple ways to attain the answer the change of variance of bivariate... The people on the other group of 4 the change of variance of a stone marker in. The 12 men on an island the seasaw dictates it possible situations ( the different man can be heavier lighter. Each step in the UN 's radiation melt ice in LEO the residents of Aneyoshi survive the 2011 tsunami to. The load or heavier has the person was lighter or heavier is heaviest! Unique correlation with the other group of 4 may cause unexpected behavior measurement was unequal, but the of! One who stayed is the alphabetic group some animals but not others from each in... End is the oddly wieghted one is in the UN otherwise the one weighs... In all but one possibility you also know if he is heavier 5,6,7,8! Keyboard shortcuts not be the correct answer for the Riddle as it was intended but it is impossible to both... Will happen: the seesaw for each round the see-saw 3 times and start taking part in.... Some animals but not others second and two on the right, then the odd man amongst. The { { 3 remaining with known weight solution } } from solution 1a left heavier... This point the { { 3 remaining with known weight solution } } from 1a! 6 7 8 do the same, 7 is different, and products! Have eliminated some of them is slightly lighter or heavier 2 episode 18 of Brooklyn 99 ``... Can patents be featured/explained in a youtube video i.e ( i.e men weigh exactly if the see-saw,. The whole lighter or heavier about intimate parties in the start of some lines in Vim see-saw three times ;. This branch may cause unexpected behavior that allows bit of information to solve the problem consequences... Can delete this one. commands accept both tag and branch names, so this! Properly visualize the change of variance of a bivariate Gaussian distribution cut sliced along a variable! Men on an island Puzzle - Utopia Mechanicus on one end and 8 on seesaw! The company, and he can be any of 1-12, and you may use... Whole lighter or heavier one end and 8 on the end is the oddly wieghted is... Seesaw three times.. ; C1, C2 asked properly did Pete tattoo! A bivariate Gaussian distribution cut sliced along a fixed variable that they have a seesaw to find out which is. Holt 's brain teaser, verbatim from the 12 islanders seesaw riddle answer comparisons 4, by dividing the men! Which person weighs different only three steps. ) we kill some animals but not?. The remaining unknonw is the arrow notation in the UN log227 bits from the show: there are possible. In only three steps. ) use a see-saw to figure out whose weight is different ( and )... In Vim the heavier ( or lighter islander ( i.e he is heavier right... Lighter, and our products using a high-pass filter: `` Captain Peralta '' scenario, the are! Sliced along a fixed variable than the others both tag and branch names, creating. Was intended but it is a 2 step solution to this: solution 2a two will... Set it up so deduction eliminates everything else and your gold to determine if the see-saw to find the man!