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Topic: A strange probabilistic question 


If you choose an answer to this question at random, what is the probability that you will be correct? A) 25% B) 50% C) 0% D) 25% :bg: 


"this question " is illdefined. 


The choices defat each other in a nontransitive cycle (think rock/paper/scissors, where none of the choices are always the best), so none of the answers can be chosen at random with the correct probability. 


Imagine this were not a multiple choice question. Rather than asking the probability of answering the question, ask what is the correct answer. If it is answerable then there is some probability >0 of being correct if answering at random; if not answerable, then the P=0. There is no way to distinguish between the two cases. 


[quote]On Nov 3, 2018, landmark wrote: "this question " is illdefined. [/quote] What if the options would be: A) 25% B) 50% C) This question is illdefined D) 25% 


[quote]On Nov 3, 2018, Scott Cram wrote: The choices defat each other in a nontransitive cycle (think rock/paper/scissors, where none of the choices are always the best), so none of the answers can be chosen at random with the correct probability. [/quote] If you cannot choose the correct answer, so 0% is the correct answer; but you can choose "0%" from the multiple options available. :D 


Choice C (illdefined) case is not an answer; it is a statement about the nature of the question.It could just as well be replaced by "I like this question." 


Landmark, I agree with you, I was just in the role of puzzleproposer. :bg: 