The answer is C...

assuming:

A1: That there must exist a correct answer and the correct answer is a member of the set (A,B,C,D)

A2: A correct answer is a choice with a value that satisfies the equation X= c/n where n is the number of answers to choose from, where c is the count of the times the answer appears in the choice list ,and where X is the value of the chosen answer

Conclusion 1: (B) 0% can never satisfy A2 , as both c and n are integers >= 1 ,and any positive integer divided by another is greater than zero. (from A2)

The Paradox, : No other Answer satisfies all assumptions. . While the answer would be 25% if it's count was one, the count is 2. As such you actually have a have a 50% chance to hit (A or D). Additionally you only have a 25% chance to randomly select 50%. To avoid this paradox, (A or D) and (C) cannot logically exist together in a 4-count answer set. (from A1, A2)

C2: Thus either (A or D) must not exist or (C) must not exist (A1, A2, paradox)

C3: If (C) did not exist, then (ABD) or or smaller potential subsets would remain.

C4. (ABD) all answers are incorrect B is always incorrect and A and D's c/n is not equal to it's X. (A2)

C5. No small subset (AD) (AB) (BD) (A) (B) (D) () satisfies A1 and A2

C6: Thus (A or D) doesn't exist, (C2, C3, C4,C5)

C7: Neither (A not existant) nor (D not existant) separately is sufficient to safisfy A2. As this would leave 3 unique (1-count) answers, one of which is zero and none of which are 33 and one third % (A2)

C8: Therefore (A non-existent) and (D non-existent.) (C7, C2)

C9: This leaves B and C as the remaining possibly existing options, and of the two only C satisfies all assumptions (A1, A2. C8)

Isn't it just lovely?

@randygalbraith I agree with your Medicare for All and a rights-based system comments and admire the way you engage your daughter in these kinds of thoughtful conversations.

Thanks @Ted. There is a passage from Deuteronomy 6 that tells parents to teach their children. But... but... but... I'd say it really is a two-way street. I learn so much from my daughters. Montana is on the autism spectrum and she often speaks very rapidly with few breaks. I'm still working on it... but I now try to a patient and careful listener.

Stupide oui, mais pourquoi les chercheurs n'ont-ils pas laissé un voice mail ? Ou envoyer un SMS ?