• Untamed_Star
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          9 days ago

          if c was correct then it would be 25% then 50% and then 25% again ans 50% and 25%

        • Cethin@lemmy.zip
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          8 days ago

          The answer “there is no correct answer” is correct, but the answer isn’t 0%. It’s a paradox. There isn’t a solution, which isn’t the same thing as saying there’s a 0% chance of getting the right solution (when that is one of the choices).

          • Natanael@infosec.pub
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            8 days ago

            Essentially there’s a difference between “0% of answers will be correct (because none can be)” and “the listed 0%-option self-invalidates if selected”. The problem is the interaction between answers that shouldn’t be there in normal tests, which changes the values after selection.

            Therefore, the only winning move is not to play.

              • Natanael@infosec.pub
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                8 days ago

                If c is correct for you then it’s also correct for those who answered at random. And if it is, then you’re all wrong because you’re answering about those who answered at random.

                The only viable approach to actually answer is to argue that the question is ambiguous and that while the hypothetical test takers face infinite recursion you the real test taker don’t have to resolve the infinite recursion and to then choose a place to halt evaluation. And if they disagree then your solution to the Halting problem invoke the all powerful oracle function “I’ll talk to the principal”.

                • Cethin@lemmy.zip
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                  8 days ago

                  It’s not necessary to use recursion. Simple logic solves it. If a or c are true, that implies a and c are not true. If b is true, that implies b isn’t true. If d is true, that implies d isn’t true. No recursion needed and this is complete. You could take a recursive approach, but it doesn’t halt, like you said, so it doesn’t give a result.

                  (Also, the halting problem is determining if something halts, not what the value is at the end. This problem does not halt, if done recursively. The halting problem is easy to resolve for this particular problem.)

  • Mikina@programming.dev
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    9 days ago

    Couldn’t you argue that 0% is correct?

    It’s a paradox, no of the answers can be correct, so the chance that you pick the correct one is 0%.

    Sure, by picking it, it makes it wrong, but you don’t care about that.

    If you ran a infite monte carlo test on it, you’d end up with 0% correct answers.

    Sure, picking the zero makes it not true again, but you don’t care about that - it prooves that the statistical test holds.

    • AirBreather@lemmy.world
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      9 days ago

      Nah it’s a paradox. There’s no such thing as just a freestanding Monte Carlo test that you can just “run” - you do actually need to define enough parameters to make it tell you anything.

      This kind of self-referential stuff feels like a proof of Gödel’s incompleteness theorems with extra steps.

    • Brave Little Hitachi Wand@feddit.uk
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      9 days ago

      The trick is that there is no paradox, only the implication of one. ‘If’ being the key word - you’re not actually being asked to answer randomly, but you are being subtly trolled.

      • prime_number_314159@lemmy.world
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        8 days ago

        You do not need to pick at all for the paradox to exist. If either A or D is correct, the other is also correct, and the random odds of selecting the correct answer should have been 50%. This is a contradiction. Neither A nor D can be the correct answer.

        If B is correct, the random odds of selecting it is only 25% - a contradiction, so B cannot be correct. Likewise, if C is correct, there is a 25% chance of randomly picking C. C is also not correct.

        None of the four answers is correct, so there is a 0% chance of randomly picking the correct answer. C is correct, contradiction, C is not correct, C is correct, is not, is too, etc.

        The paradox is resolved by knowing the the scantron answer key has A selected. D is not sufficiently identical to A in javascript, so only the students that randomly guessed the correct answer will get credit.

        Because the paradox can only be resolved with either A or D as the selected answer, well informed students picking randomly would have a 50% success rate.

    • balsoft@lemmy.ml
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      9 days ago

      If you ignore self-referential nature of the question and stop the iteration at some point, sure, you can argue that any answer is correct.

      If you ran a infite monte carlo test on it, you’d end up with 0% correct answers.

      That would mean your Monte Carlo test is set up incorrectly because at least 1/4 of the results of the test would be the “correct” answer as per your own argument, thus invalidating it.

  • Anas@lemmy.world
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    8 days ago

    C; the question has two identical answers, it gets removed from the test based on that error

  • SCmSTR
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    9 days ago

    Lmao that’s fucked up hahaha

  • yoriaiko
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    9 days ago

    It’s B - 50%; either correct (50%) or false (50%), binary 0/1, yes/no, score or not.

  • Crozekiel@lemmy.zip
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    9 days ago

    I would answer C) 0% - Ultimately I feel this isn’t a “pick the correct answer” type of test and more of a “pick the best answer” type of test.

    My reasoning is there are really two questions - one is being answered at random, the other I am answering. The one being answered at random is making any answer it chooses wrong - If it picks A or D (25%), then the correct answer is B (50%). If it picks B (50%), then the answer is either A or D (25%). If it chooses C (0%) then the correct answer is A or D (25%) again. No matter which one is chosen at random, it becomes wrong as soon as it is chosen. So then back to the question on the test that I am answering, the correct answer is C) 0%.

    Also, if the teacher marks that wrong, then I am even more correct.

    • dogdeanafternoon@lemmy.ca
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      9 days ago

      It’s definitely B ) 50%. Ignoring the values for answers, there can only be 1 “correct” answer. If you have 4 options and 1 can be correct, a random guess is 25%. Since there are 2 options for 25%, you have a 50% chance of guessing the correct 25%.

    • chonglibloodsport@lemmy.world
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      8 days ago

      You can’t separate the question like that. Whichever answer you circle indicates your assertion that this is the probability of getting the correct answer by uniform random chance.

      This means that any answer you circle is wrong, and so the correct answer is to not circle any of them. You could even write e) none of the above to indicate that you have deliberately chosen not to circle one of them instead of skipping the question.

      I have had plenty of exams with multiple choice questions that included the possibility of no correct answers, one correct answer, or even multiple correct answers, and we were expected to make that judgement (rather than blindly follow instructions).

        • chonglibloodsport@lemmy.world
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          8 days ago

          They’re called multi-select questions and you’re warned about them by the professor ahead of time. Sometimes they have a “none of the above” option but sometimes they don’t.

          The purpose is to get you to think critically. If you look at a question and all of the options seem wrong to you, making a guess because “one of them has to be right, it’s multiple choice” is lazy thinking and has nothing to do with the subject matter. In real life you don’t have the luxury of knowing that there’s one correct answer among a set of options.

          The purpose of an exam is to test your knowledge of the course subject, not to test your ability to take multiple choice tests. Sometimes that’s hard to separate out, but the standard multiple choice question (where one and only one answer must be correct) is very game-able by guessers who don’t know the subject very well and risks the possibility of someone getting very lucky while not knowing anything.

          • 🌞 Alexander Daychilde 🌞@lemmy.world
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            8 days ago

            Well, I suppose I fell into the trap of thinking that questions with no right answers meant nobody could get a perfect score, but I would imagine that 1) it’s fair across the board and 2) accounted for in the scoring somehow.

            I suppose I was always a fan of taking easy multiple choice tests as a student - some people write them such that by using the tiniest amount of logic, someone with zero knowledge of the subject could still probably ace them, versus someone writing a diabolical one that dives deep into the subject matter and has answers that are very very slightly different and you really do have to know the material strongly to have any hope. lol. But taking a diabolical test where some questions don’t have ANY correct answers would be even MORE satisfying to ace if you really do know the material well enough, so that sounds like fun. :)

      • matlag@sh.itjust.works
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        8 days ago

        The answer is 0%: no matter what you chose, it’s wrong. Therefore, at random, you have 0% chance of picking the right answer randomly (or not).

        • chonglibloodsport@lemmy.world
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          7 days ago

          If your chance of getting the right answer is 0%, then the right answer is © 0%, giving you a 1/4 or 25% chance of being correct, thus the answer cannot be 0%.

  • bstix@feddit.dk
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    9 days ago

    The correct answer is to leave all the options unmarked.

    If you do pick an answer, then you didn’t do it randomly. When not marking the answers, the if-statement has the result of “false”, but that’s not the question.

    If your teacher then asks why you didn’t answer it, you can safely and unparadoxically claim that inaction is also an option.

    • Jyek@sh.itjust.works
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      8 days ago

      The question is not asking you to pick at random. It’s asking you to suppose that you do pick at random and to mark the correct answer not at random.

      • bstix@feddit.dk
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        8 days ago

        Technically they’re not even asking me to answer the statement.

        It only states that if I pick an answer then something. And I just don’t.

        The idea that you must mark an answer is only implied by it being a standard test.

        This might seem silly, but it happens in real life too. For instance:

        Please choose the correct answer to the question: Is Mitch McConnell dead or alive? Yes or no.

        The republicans have chosen not to answer that test. Can we blame them? Yes, but for what, they didn’t do anything? They are avoiding the Schrödinger paradox by choosing inaction. In some other kinds of cases it might be criminal to withhold information through inaction, but it’s always difficult to prove such a case.

        Buddhism also has a lot of these riddles, where the correct action or teaching is to not acknowledge the question.

    • balsoft@lemmy.ml
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      9 days ago

      If “no answer” is in the set of possible answers, then it is not a correct answer because there’s then a 20% chance of it being picked at random. But usually that’s not the case for tests anyways.

    • naught101@lemmy.world
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      9 days ago

      Severe programmer mentality 😂 I like it, but I doubt it would play out in the real world

  • balsoft@lemmy.ml
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    9 days ago

    Here’s a more fun one:

    If you pick an answer to this question at random, what is the chance that you will be correct? Mark at least one of the applicable options.

    (a) 20%

    (b) 6.25%

    (c) 0%

    (d) 20%

    And as another puzzle, what happens if you swap “at least one of the” for “all”?

    • fbs@lemmy.world
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      9 days ago

      If the answer is B, that means there’s a 25% chance of getting the right one. So the answer is A and D. But wait… that’s 50%

      50% means 25%

      That means 50%

      So it’s 0% because it’s impossible.

      Meaning it’s 25%

      Damn it

    • Scipitie@lemmy.dbzer0.com
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      9 days ago

      Not really but you’re thinking in the right direction!

      There is no correct answer because the question and the answers exclude themselves:

      For four different options it is 25% but here two options are the same - so you have a 50% chance to land on a 25% - but this means that the correct answer is only in one of the four answers, therefore you’re having a 25% chance.

      It’s a nice demonstration of what happens when the answer and question are intervined and any result changes an aspect of the answer - you’re fucked, basically.

    • Marty_TF@lemmy.zip
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      9 days ago

      well, you are either right or wrong which is 2 options, and 100%/2 is 50%. or something like that

      • bizarroland@lemmy.world
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        9 days ago

        None of the answers are correct, though, because all of the answers are correct as you work through the problem solving for correctness, but once you have actually analyzed the problem for that answer being the answer to the question, it is no longer correct.

        I’ll do a boring and pointless breakdown of it here:

        Statistically, if there are four answers and one of them is correct and it’s picked at random, then you have a 25% chance of being correct.

        There are two answers that are 25%. If you land on either one of them, that would be correct.

        That means that you have a 50% chance of being correct.

        There is only one 50% answer, which means you have a 25% chance of being correct.

        But there are two 25% answers which means the correct answer is 50%.

        But, since none of the answers are correct, then the correct answer is 0%.

        But 0% is one of the answers.

        So you have a 25% chance of being correct.

        I personally would write in “E: None of the above, 20%.”

        • Marty_TF@lemmy.zip
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          9 days ago

          i was doing a bit, shoulda marked it with an /s

          sorry you spent valuable time on my bullshit typing that out lol

        • Azteh@lemmy.world
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          9 days ago

          Well wouldn’t the correct answer for us to mark be 25% then? As we aren’t marking it randomly but we are specifically choosing it, therefore you have a 25% random chance to pick 0% which makes us marking a 25% answer correct

            • Azteh@lemmy.world
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              9 days ago

              I suppose that depends on how pedantic you want to be, cause based on how I read it, you need to “solve” the real answer, which is “c) 0%“, due to the paradoxical situation and then figure out what the chance of picking that correct answer is, if you were to randomly chose one of the 4 options, so either of the 25% options should be correct to mark as a chosen answer and not chosen randomly.

              But yes, 25% is not equal to 0%, however English is a lovely language

  • Zizzy
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    9 days ago

    Its 25%. The rules of answering a question with a set of options is that you may only choose one and only one is right unless explicitly stated otherwise. Anything else is breaking the rules, which as the taker would be disqualifying. If you start narrowing it down, as in “its 25% and theres two so now i need to guess therefore its 50” you are no longer answering the question at random and you have answered wrong. But you do have to make that coin flip. Good luck.

    • balsoft@lemmy.ml
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      9 days ago

      This is the only correct answer to the question as stated.

      That of course opens a second can of worms, since now you are actually forced to “pick the answer at random”, now with the probability of 50%. But such double entendres are typically not considered for test questions unless explicitly specified.

  • UpperBroccoli
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    9 days ago

    The right answer is neither a nor b nor c nor d, but “beer with tzatziki”.

    • balsoft@lemmy.ml
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      9 days ago

      If it’s a part of the standardized test that actually does make it much easier. A standardized test only allows to mark one option and that option needs to be derived unambiguously from the question. As such, neither A nor B are actually possible answers under this framework, D is not a possible answer to the question, and we’re left with C.

      If I was given the original question as part of some standardized test, I would probably think about it for a while, flip a coin mentally, choose either A or D, and then contest it afterwards if it gets marked as being incorrect.