Maths Problem

  • A friend was asked if they could solve this problem, thought It may cause some interesting discussion.

    Q Ifyou were to answer this question at random, what are the chances of getting itright?

     

     

    1. 25%

    2. 60%

    3. 25%

    4. 50%

  • As the available answers are 25, 50 and 60, it's one third.

    If the answer is 25% (one possibility) the probability is 0.5.
    If it's not 25% (two possibilities) the probability is 0.25.
    So the overall probability, assuming equally likely answers, is (0.5 + 0.25 + 0.25) / 3.

    If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.

  • Phil Parkin - Monday, June 12, 2017 6:27 AM

    As the available answers are 25, 50 and 60, it's one third.

    If the answer is 25% (one possibility) the probability is 0.5.
    If it's not 25% (two possibilities) the probability is 0.25.
    So the overall probability, assuming equally likely answers, is (0.5 + 0.25 + 0.25) / 3.

    Ah, but then you must account for the self-referential nature of the question.

    1/3 is not one of the options, so if the "correct" answer is 1/3, and you pick from the available answers at random, then the odds of getting it correct is 0% 🙂

    In general, this self-referential silliness generates some bizarre results.

    If the correct answer were 25%, then you would have a 50% chance of picking that by random. However, if you had a 50% chance of picking the correct answer at random, then 25% is NOT the correct answer (25!=50), so 25% can't be the answer (P->Q, Q->~P, ergo P->~P, a reductio of sorts).

    50% can't be the answer for a similar reason, because if 50% is the correct answer, you only have a 25% chance of picking it at random, and again, 25!=50, so 50% is incorrect.

    Similar reasoning applies to 60%.

    So, really, the answer is 0%, but that's also not an available answer 🙂

    So many contradictions...where's Graham Priest when you need him? 🙂

    EDIT: Added a silly dialetheism reference for fun. All a bit tongue-in-cheek (but only a bit).

  • been done on many sites.....here's one with 844 comments  :w00t::w00t:

    https://flowingdata.com/2011/10/28/best-statistics-question-ever/

    ________________________________________________________________
    you can lead a user to data....but you cannot make them think
    and remember....every day is a school day

  • Jacob Wilkins - Monday, June 12, 2017 9:45 AM

    Ah, but then you must account for the self-referential nature of the question.

    1/3 is not one of the options, so if the "correct" answer is 1/3, and you pick from the available answers at random, then the odds of getting it correct is 0% 🙂

    Well said, Jacob.  That's the way I read it.

  • Ed Wagner - Monday, June 12, 2017 10:35 AM

    Jacob Wilkins - Monday, June 12, 2017 9:45 AM

    Ah, but then you must account for the self-referential nature of the question.

    1/3 is not one of the options, so if the "correct" answer is 1/3, and you pick from the available answers at random, then the odds of getting it correct is 0% 🙂

    Well said, Jacob.  That's the way I read it.

    I don't see anywhere in the original text where it states that this is a multiple choice question, and therefore the answer need not be limited to one of the provided options. At least, that's how I read it 🙂

    If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.

  • Phil Parkin - Monday, June 12, 2017 10:44 AM

    Ed Wagner - Monday, June 12, 2017 10:35 AM

    Jacob Wilkins - Monday, June 12, 2017 9:45 AM

    Ah, but then you must account for the self-referential nature of the question.

    1/3 is not one of the options, so if the "correct" answer is 1/3, and you pick from the available answers at random, then the odds of getting it correct is 0% 🙂

    Well said, Jacob.  That's the way I read it.

    I don't see anywhere in the original text where it states that this is a multiple choice question, and therefore the answer need not be limited to one of the provided options. At least, that's how I read it 🙂

    Indeed. The upshot is that the question is poorly framed. One must make additional assumptions to conclude much of anything about it (why I said my response was tongue-in-cheek, if only a bit).

    Of course, if the answer is NOT limited to one of the provided options, then it's hard to give any answer at all.

    What is the problem space here (is it a yes/no question, open-ended, or what?)? What is the distribution of the prior probabilities across potential answers?

    Is it a question to which any real number is a potential solution, and the prior is uniform? Well, then 0% is again a closer answer 🙂

    Just a poorly framed question that admits of thinking through some interesting concepts and careful examination of assumptions (or less charitably, a trick question) 🙂

  • Answer options are not "25%, 50% or 60%".
    It's actually "A, B, C or D"
    So, the probability of guessing it right is 25%.

    _____________
    Code for TallyGenerator

  • guess you'll have one-in-three chance..anyways, here's a nice probability lesson, which i found when working for this web site..

  • Such a question is:

    1.) IMPROPER, as it violates the basic separation of question from answer.  Such questions can NOT be properly answered without invalidating the question.
    2.) IMPROPER because it has no correct answer because the criteria for answering it are not sufficiently detailed.
    3.) Serves no useful purpose.   Encouraging silly commentary is NOT a "useful purpose", as it accomplishes zip, zilch, and nada.

    Steve (aka sgmunson) 🙂 🙂 🙂
    Rent Servers for Income (picks and shovels strategy)

  • 100%

    Just walk away and  ignore this type of nonsense and you'll win.

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