June 12, 2017 at 2:28 am
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?
25%
60%
25%
50%
June 12, 2017 at 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.
The absence of evidence is not evidence of absence
- Martin Rees
The absence of consumable DDL, sample data and desired results is, however, evidence of the absence of my response
- Phil Parkin
June 12, 2017 at 9:45 am
Phil Parkin - Monday, June 12, 2017 6:27 AMAs 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).
June 12, 2017 at 10:21 am
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
June 12, 2017 at 10:35 am
Jacob Wilkins - Monday, June 12, 2017 9:45 AMAh, 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.
June 12, 2017 at 10:44 am
Ed Wagner - Monday, June 12, 2017 10:35 AMJacob Wilkins - Monday, June 12, 2017 9:45 AMAh, 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 🙂
The absence of evidence is not evidence of absence
- Martin Rees
The absence of consumable DDL, sample data and desired results is, however, evidence of the absence of my response
- Phil Parkin
June 12, 2017 at 11:23 am
Phil Parkin - Monday, June 12, 2017 10:44 AMEd Wagner - Monday, June 12, 2017 10:35 AMJacob Wilkins - Monday, June 12, 2017 9:45 AMAh, 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) 🙂
June 14, 2017 at 8:34 pm
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
September 29, 2017 at 7:29 am
guess you'll have one-in-three chance..anyways, here's a nice probability lesson, which i found when working for this web site..
October 2, 2017 at 10:10 am
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)
October 4, 2017 at 8:47 am
100%
Just walk away and ignore this type of nonsense and you'll win.
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