Timeline for Batman vs 4 villains
Current License: CC BY-SA 3.0
34 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 19, 2018 at 18:39 | comment | added | oobug | @Suthek Whoops! Good catch! I have rephrased the question so that it still possesses the question's original logic (thereby not changing the answer), but has now been converted to proper boolean yes/no logic. Thank you for spotting that! | |
| Jan 19, 2018 at 18:36 | history | edited | oobug | CC BY-SA 3.0 |
Fixed incorrectly phrased yes-or-no question.
|
| Jan 19, 2018 at 12:10 | comment | added | Suthek | Sorry for Necroing; took a bit to get the points, but I've wanted to point this out since I first read this after it was posted: "If I were to ask the villain in position [order number] if they are The Riddler, what would they answer?" is not a Yes/No question. While it's true that its possible answers are "Yes" and "No", this is the equivalent of writing a program that outputs true or false vs a program that outputs the strings "true" or "false". As such, the villains would hang up and Gotham is doomed. | |
| Oct 16, 2017 at 20:43 | vote | accept | Saladani | ||
| Sep 26, 2017 at 4:01 | vote | accept | Saladani | ||
| Sep 26, 2017 at 4:01 | |||||
| Sep 24, 2017 at 13:04 | comment | added | Jasper | @oobug Yes, that's why it was added. However, I'd say it also logically flows from his core tenet of "misleading as much as possible". If you pin him down as either the Joker or The Penguin (by eliminating Two-Face) his best strategy to mislead you is to keep impersonating The Penguin. It is not mentioned whether the others can hear the questions and answers of each other, but the assumption that they don't is a pretty big one (as is that they do). It makes sense to assume good logicians who know the rules of the game and calling someone "inherently unreliable" doesn't change that. | |
| Sep 24, 2017 at 7:07 | comment | added | oobug | @boboquack Correct, I should have clarified that the question is logically impossible to answer truthfully. The equivalent of the logically unanswerable question for characters forced to lie is "Is 'Yes' the answer to this question?" | |
| Sep 24, 2017 at 6:20 | comment | added | boboquack | That is logically answerable - "No" (lying) | |
| Sep 23, 2017 at 22:46 | comment | added | oobug | @Jasper Example of a logically unanswerable question: "Is 'No' the answer to this question?" | |
| Sep 23, 2017 at 22:43 | comment | added | oobug | @Jasper Oh I see. That (and the following) paragraph was added later as a provision to ensure Joker will never pass, even if the question is logically unanswerable. The Joker's behavior should really be described more like, "Joker will answer yes or no to every question, choosing his answer each time based on what will most mislead Batman." Also, the puzzle does not indicate that the villains will know each other's answer, and even if they do, The Joker is an inherently unpredictable character, so the other villains will never know and will always have to pass when asked about his answers. | |
| Sep 23, 2017 at 21:33 | comment | added | Jasper | @oobug "AND b) There is a way to answer the question while remaining logically consistent" | |
| Sep 23, 2017 at 16:35 | comment | added | oobug | @Jasper Where in the original puzzle does it say that the Joker tries to be consistent? | |
| Sep 23, 2017 at 8:19 | comment | added | Jasper | There's a flaw in this answer. The first time you asked The Joker whether he is The Riddler, he answered either yes or no. Since he tries to be consistent, he knows what he'd answer if you were to actually ask him that question. So do the other villains. Your answer relies on them on knowing that, so it isn't going to work... | |
| Sep 22, 2017 at 22:08 | comment | added | oobug | @BogdanAlexandru The problem with that logic is that, if The Joker is in position 2, an answer of either yes or no will be equally misleading. Two-Face truly doesn't know what The Joker's answer will be, and since he must either answer truthfully, untruthfully, or pass, he is guaranteed to pass. | |
| Sep 22, 2017 at 12:57 | comment | added | Danikov | @BogdanAlexandru you're half-right. Two-Face's answers are all logically consistent: if he doesn't pass, he enables the Joker to be malicious, making the Joker's answer predictable, but if he does pass, the Joker doesn't know what to choose and his action does become unknowable. The rules suggest Two-Face will flip a coin and attempt to answer truthfully or not before considering passing, though, so I agree with your gotcha, but I don't think it undermines that it is possible in 4 or 5 questions. | |
| Sep 22, 2017 at 9:25 | comment | added | Bogdan Alexandru | Very, very nice try, however there is a problem with scenario 1: "If Two-Face passes, that character is The Joker." You would have to prove that The Joker will answer randomly. I don't believe that is the case, because if that character is The Joker, he will apply the same logic as you do, and he will answer Yes or No to mislead you. Now assuming Two-Face is on the same thinking level, he will also know which answer is the misleading answer that The Joker will give, and therefore he will flip a coin and give an answer himself. | |
| Sep 21, 2017 at 13:42 | comment | added | Danikov | Ah, maybe I'm wrong; the Joker's misinformation multiplies out the 24 possibilities into 48 possibilities, which is less than the 3^3 = 27 bits of information obtainable from the other three villains. | |
| Sep 21, 2017 at 13:15 | comment | added | Danikov | I have a nagging feeling it can be done in 4 reliably, but it's tricksy. | |
| Sep 21, 2017 at 10:34 | comment | added | Danikov | I think you're right, the more I think of it, Joker should be treated as a random selection of yes/no. He cannot predict Batman's strategy so, while sometimes he might answer later and there's an obvious answer that gives away information to avoid, sometimes he might go first and he cannot predict Batman will ask the same question again later on. | |
| Sep 20, 2017 at 16:53 | comment | added | oobug | @Danikov Thanks for the suggestions! I've cleaned up the original question. I don't want to entirely remove scenario 2 since it proves this technique will work for any set of answers, but I have edited the wording to clarify the scenario's unlikelihood. | |
| Sep 20, 2017 at 16:51 | history | edited | oobug | CC BY-SA 3.0 |
Edited to incorporate @Danikov's suggestions
|
| Sep 20, 2017 at 15:09 | comment | added | Danikov | I don't think the qualifier 'on the next round of questions' is needed. I'd also hand-wave 2 away as Joker can't answer that way as it gives away too much information and lets Batman find him early. | |
| Sep 20, 2017 at 6:38 | comment | added | oobug | Re-edited my answer; still using basically the same technique. The minimum number of questions is now 4. | |
| Sep 20, 2017 at 6:37 | history | edited | oobug | CC BY-SA 3.0 |
Slight modification to technique; reduced the minimum number of questions to 4.
|
| Sep 19, 2017 at 22:33 | history | edited | oobug | CC BY-SA 3.0 |
Trying to fix weird formatting on mobile
|
| Sep 19, 2017 at 22:12 | comment | added | oobug | I just completely rewrote my answer. I've been thinking about this puzzle way too much. | |
| Sep 19, 2017 at 22:11 | history | edited | oobug | CC BY-SA 3.0 |
Completely rewrote my answer, it takes only 5 questions now.
|
| Sep 19, 2017 at 17:54 | history | edited | oobug | CC BY-SA 3.0 |
Modified my methods to reduce the maximum number by one.
|
| Sep 19, 2017 at 8:18 | comment | added | oobug | @boboquack Evidently my math was bad. But that makes my answer better! | |
| Sep 19, 2017 at 8:17 | history | edited | oobug | CC BY-SA 3.0 |
Sometimes I can't math so good.
|
| Sep 19, 2017 at 8:10 | comment | added | oobug | @boboquack You're right, I could actually refine it a lot. If I started with question #2 I could find Two-Face and The Joker faster. But I need to go to sleep. I'll take a look in the morning. | |
| Sep 19, 2017 at 7:54 | comment | added | boboquack | Why is 8 the minimum? | |
| Sep 19, 2017 at 7:49 | review | First posts | |||
| Sep 19, 2017 at 7:54 | |||||
| Sep 19, 2017 at 7:48 | history | answered | oobug | CC BY-SA 3.0 |