• bratorange@feddit.orgEnglish
    131·
    5 hours ago

    This can also be used a great example of proof by contradiction: There is no correct answer in the options. Proof: Assume there was a correct answer in the options. Then it must be either 25%, 50% or 60%. Now we make a case distinction.

    (A) Assume it was 25. Then there would be two of four correct options yielding in a probability of 50%. Therefore 50 must be the correct answer. -> contradiction.

    (B) Assume it was 50. Then there would be one of four correct options yielding in a probability of 25%. Therefore the answer is 25. -> contradiction.

    © Assume it was 60%. Since only 0,1,2,3 or 4 of the answers can be correct the probability of choosing the right answer must be one of 0% 25% 50% 75% or 100%. -> contradiction.

    Because of (A), (B) and ©, it cannot be 25, 50% or 60%. -> contradiction.

  • sqgl@beehaw.orgEnglish
    3·
    4 hours ago

    It was only the next day that I returned to this post realising that “this question” isn’t even defined.

  • technocrit@lemmy.dbzer0.comEnglish
    111·
    14 hours ago

    If you’re choosing the answer, then there is 100% chance of being correct. Since none of these answers is 100%, the chance is 0%.

  • Tiger666@lemmy.caEnglish
    81·
    16 hours ago

    Thanks for making me laugh all alone in my car before heading in to work. I wish I could give you an award. Cheers!

  • nialv7@lemmy.worldEnglish
    581·
    1 day ago

    The question is malformed and the correct answer isn’t listed in the multiple choices. Therefore the correct answer is 0%

  • xthexder@l.sw0.comEnglish
    322·
    1 day ago

    It’s probably graded by a computer, and a) or d) is a fake answer, since the automated system doesn’t support multiple right answers.

    I’m going to go with 25% chance if picking random, and a 50% chance if picking between a) and d).
    If it’s graded by a human, the correct answer is f) + u)

  • moakley@lemmy.worldEnglish
    1515·
    1 day ago

    B.

    This is a multiple choice test. Once you eliminate three answers, you pick the fourth answer and move on to the next question. It can’t be A, C, or D, for reasons that I understand. There’s a non-zero chance that it’s B for a reason that I don’t understand.

    If there is no correct answer, then there’s no point hemming and hawing about it.

    B. Final answer.

    • lugal@lemmy.dbzer0.comEnglish
      602·
      1 day ago

      I love this, it shows how being good at (multiple choice) tests doesn’t mean you’re good at the topic. I’m not good at tests because my country’s education system priorities understanding and problem solving. That’s why we fail at PISA

    • blandfordforever@lemm.eeEnglish
      10·
      1 day ago

      Entertaining response but I disagree.

      I’m going to say that unless you’re allowed to select more than one answer, the correct answer is 25%. That’s either a or d.

      By doing something other than guessing randomly (seeing that 1 in 4 is 25% and that this answer appears twice), you now have a 50% chance of getting the answer correct. However, that doesn’t change the premise that 1 in 4 answers is correct. It’s still 25%, a or d.

      • moakley@lemmy.worldEnglish
        13·
        1 day ago

        That’s an interesting perspective. The odds of correctly guessing any multiple choice question with four answers should be 25%. But that assumes no duplicate answers, so I still say that’s wrong.

        • blandfordforever@lemm.eeEnglish
          41·
          24 hours ago

          I’m going to double down and say that on a real life test, this would likely represent a typo. In such case, I think you could successfully defend a 25% answer while a 60% answer is just right out the window, straight to jail.

        • the_q@lemm.eeEnglish
          17·
          1 day ago

          No of course not, but the question is more important to the answer than the “correct” answer.

              • CileTheSane@lemmy.caEnglish
                4·
                23 hours ago

                It’s not a puzzle. It’s just wrong.

                “Which of the following is a mammal:
                A) rock
                B) time
                C) verb
                D) Enui”

                Is not a puzzle.

                • Kage520@lemmy.worldEnglish
                  3·
                  14 hours ago

                  Based on previous guy’s logic: D.

                  I know A, B, and C are definitely wrong, but I’m not sure I fully understand D. So it’s D and move on.

                  Reality is I make a note and discuss with the teacher if they don’t notice themselves when tests come back.

  • seeigel@feddit.orgEnglish
    11·
    1 day ago

    What’s the correct value if the answer is not picked at random but the test takers can choose freely?

  • Reddfugee42@lemmy.worldEnglish
    16772·
    1 day ago

    This is a self-referential paradox — a classic logic puzzle designed to be tricky. Let’s break it down:

    Step-by-step analysis:

    1. How many choices? There are 4 possible answers, so if we pick one randomly, the chance of picking any specific one is 1 in 4 = 25%.

    2. How many answers say “25%”? Two.

    3. That means the probability of randomly choosing an answer that says “25%” is 2 in 4 = 50%.

    4. But if the correct answer is 50%, then only one option says “50%” — which is ©. So the probability of picking it at random is 1 in 4 = 25%, contradicting the idea that 50% is correct.

    5. If the correct answer is 25%, then two options say that — a and d. So the chance of picking one of those at random is 50%, not 25% — again a contradiction.

    6. Similarly, if 60% is correct (only one option), then the chance of picking it randomly is 25%, which again makes it incorrect.

    Conclusion: Any choice leads to a contradiction. This is a self-referential paradox, meaning the question breaks logical consistency. There is no consistent correct answer.