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.

(C) 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 (C), it cannot be 25, 50% or 60%. -> contradiction.

It was only the next day that I returned to this post realising that "this question" isn't even defined.

0%

The only winning move is not to choose

The answer is clear

I choose 75%

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%.

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

This is a conundrum wrapped in a turducken, swaddled in nesting dolls.

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

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)

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.

42

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

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 (c). 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.