0:00:08.980,0:00:12.163 Before he turned physics upside down, 0:00:12.163,0:00:15.849 a young Albert Einstein supposedly[br]showed off his genius 0:00:15.849,0:00:21.952 by devising a complex riddle involving[br]this list of clues. 0:00:21.952,0:00:24.105 Can you resist tackling a brain teaser 0:00:24.105,0:00:27.123 written by one of the smartest [br]people in history? 0:00:27.123,0:00:28.596 Let's give it a shot. 0:00:28.596,0:00:32.676 The world's rarest fish has been[br]stolen from the city aquarium. 0:00:32.676,0:00:38.786 The police have followed the scent to a[br]street with five identical looking houses. 0:00:38.786,0:00:41.291 But they can't search [br]all the houses at once, 0:00:41.291,0:00:45.244 and if they pick the wrong one,[br]the thief will know they're on his trail. 0:00:45.244,0:00:50.189 It's up to you, the city's best detective,[br]to solve the case. 0:00:50.189,0:00:53.491 When you arrive on the scene,[br]the police tell you what they know. 0:00:53.491,0:00:55.131 One: 0:00:55.131,0:00:58.215 each house's owner [br]is of a different nationality, 0:00:58.215,0:00:59.716 drinks a different beverage, 0:00:59.716,0:01:02.709 and smokes a different type of cigar. 0:01:02.709,0:01:03.568 Two: 0:01:03.568,0:01:08.060 each house's interior walls[br]are painted a different color. 0:01:08.060,0:01:08.933 Three: 0:01:08.933,0:01:14.607 each house contains a different animal,[br]one of which is the fish. 0:01:14.607,0:01:18.428 After a few hours of expert sleuthing,[br]you gather some clues. 0:01:18.428,0:01:20.546 It may look like a lot of information, 0:01:20.546,0:01:23.597 but there's a clear logical path[br]to the solution. 0:01:23.597,0:01:26.203 Solving the puzzle will be[br]a lot like Sudoku, 0:01:26.203,0:01:32.668 so you may find it helpful to organize[br]your information in a grid, like this. 0:01:32.668,0:01:36.415 Pause the video on the following screen to[br]examine your clues and solve the riddle. 0:01:39.285,0:01:40.115 Answer in: 3 0:01:40.115,0:01:41.146 2 0:01:41.146,0:01:42.307 1 0:01:42.307,0:01:47.024 To start, you fill in the information[br]from clues eight and nine. 0:01:47.024,0:01:51.455 Immediately, you also realize that since[br]the Norwegian is at the end of the street, 0:01:51.455,0:01:53.639 there's only one house next to him, 0:01:53.639,0:01:57.383 which must be the one with the blue walls[br]in clue fourteen. 0:01:57.383,0:02:01.695 Clue five says the green-walled[br]house's owner drinks coffee. 0:02:01.695,0:02:06.215 It can't be the center house since you[br]already know its owner drinks milk, 0:02:06.215,0:02:11.211 but it also can't be the second house,[br]which you know has blue walls. 0:02:11.211,0:02:12.561 And since clue four says 0:02:12.561,0:02:16.823 the green-walled house must be directly[br]to the left of the white-walled one, 0:02:16.823,0:02:20.077 it can't be the first [br]or fifth house either. 0:02:20.077,0:02:22.707 The only place left [br]for the green-walled house 0:02:22.707,0:02:25.694 with the coffee drinker[br]is the fourth spot, 0:02:25.694,0:02:28.841 meaning the white-walled house[br]is the fifth. 0:02:28.841,0:02:31.884 Clue one gives you [br]a nationality and a color. 0:02:31.884,0:02:35.539 Since the only column missing both[br]these values is the center one, 0:02:35.539,0:02:38.923 this must be the Brit's red-walled home. 0:02:38.923,0:02:41.964 Now that the only unassigned [br]wall color is yellow, 0:02:41.964,0:02:44.467 this must be applied to the first house, 0:02:44.467,0:02:47.455 where clue seven says [br]the Dunhill smoker lives. 0:02:47.455,0:02:51.663 And clue eleven tells you that[br]the owner of the horse is next door, 0:02:51.663,0:02:55.002 which can only be the second house. 0:02:55.002,0:02:59.651 The next step is to figure out what[br]the Norwegian in the first house drinks. 0:02:59.651,0:03:03.015 It can't be tea, clue three tells you[br]that's the Dane. 0:03:03.015,0:03:08.674 As per clue twelve, it can't be root beer[br]since that person smokes Bluemaster, 0:03:08.674,0:03:11.370 and since you already [br]assigned milk and coffee, 0:03:11.370,0:03:13.167 it must be water. 0:03:13.167,0:03:14.456 From clue fifteen, 0:03:14.456,0:03:18.076 you know that the Norwegian's neighbor,[br]who can only be in the second house, 0:03:18.076,0:03:20.170 smokes Blends. 0:03:20.170,0:03:23.124 Now that the only spot in the grid[br]without a cigar and a drink 0:03:23.124,0:03:24.600 is in the fifth column, 0:03:24.600,0:03:27.908 that must be the home of the person[br]in clue twelve. 0:03:27.908,0:03:31.403 And since this leaves only the second[br]house without a drink, 0:03:31.403,0:03:35.615 the tea-drinking Dane must live there. 0:03:35.615,0:03:40.686 The fourth house is now the only one[br]missing a nationality and a cigar brand, 0:03:40.686,0:03:45.181 so the Prince-smoking German[br]from clue thirteen must live there. 0:03:45.181,0:03:48.623 Through elimination, you can conclude[br]that the Brit smokes Pall Mall 0:03:48.623,0:03:51.470 and the Swede lives in the fifth house, 0:03:51.470,0:03:53.684 while clue six and clue two tell you 0:03:53.684,0:03:57.807 that these two have a bird [br]and a dog, respectively. 0:03:57.807,0:04:01.974 Clue ten tells you that the cat owner[br]lives next to the Blend-smoking Dane, 0:04:01.974,0:04:05.440 putting him in the first house. 0:04:05.440,0:04:07.658 Now with only one spot left on the grid, 0:04:07.658,0:04:11.750 you know that the German in the [br]green-walled house must be the culprit. 0:04:11.750,0:04:13.695 You and the police burst into the house, 0:04:13.695,0:04:16.783 catching the thief fish-handed. 0:04:16.783,0:04:18.933 While that explanation [br]was straightforward, 0:04:18.933,0:04:23.749 solving puzzles like this often[br]involves false starts and dead ends. 0:04:23.749,0:04:26.479 Part of the trick is to use [br]the process of elimination 0:04:26.479,0:04:30.505 and lots of trial and error[br]to hone in on the right pieces, 0:04:30.505,0:04:32.359 and the more logic puzzles you solve, 0:04:32.359,0:04:34.211 the better your intuition will be 0:04:34.211,0:04:39.035 for when and where there's enough [br]information to make your deductions. 0:04:39.035,0:04:42.238 And did young Einstein [br]really write this puzzle? 0:04:42.238,0:04:43.678 Probably not. 0:04:43.678,0:04:44.988 There's no evidence he did, 0:04:44.988,0:04:47.784 and some of the brands mentioned[br]are too recent. 0:04:47.784,0:04:49.460 But the logic here is not so different 0:04:49.460,0:04:53.181 from what you'd use to solve equations[br]with multiple variables, 0:04:53.181,0:04:55.782 even those describing [br]the nature of the universe.