Gah. Fiendish probability question

[Recursion]

Suppose you were to pick one of the four answers below at random (p = 0.25 for each answer). What is the probability your pick would be correct?

A. 25%
B. 50%
C. 0%
D. 25%

[baldguy]

1. A fish.

[Ptah]

2. 33%

[denbot]

3. 42

Would towel also be acceptable?

[The Velveteen Ocelot]

4. My hovercraft is full of eels.

But I think the answer is 0%.

[drm604]

5. Undecidable

The self-referential nature of the problem combined with the given answers makes the answer a moving target.

If I say %25 then since both A and D say 25% there's a 50% chance that a random choice would pick that, but that means that %50 is the correct answer and there's only a 25% chance of picking that. But if there's a 25% chance then there's a 50% chance...

I could get out of that by saying that there's no correct answer but that means a 0% chance that I would get the right answer and C says 0% so there's a 25% chance that I'll pick that...

[cyberswede]

6. You're freakin' me out...

[drm604]

7. Exactly!

That Star Trek episode is another example of a self-referential paradox.

http://en.wikipedia.org/wiki/Category:Self-referential_paradoxes

The problem posed by the OP is a paradox. You can't say that it has an answer and you can't say that it doesn't have an answer. It's a meaningless question, just like "I am lying" is meaningless. (Of course, that robot is very poorly programmed if it can't handle nonsensical statements without going into a loop and overheating. )

[femmocrat]

9. Kittens.

Why are A and D the same? Is this from Common Core math or sum'thin?

[drm604]

10. It's constructed like that to create a paradox.

See my post #5.

I highly doubt that it's in common core unless it's a demonstration regarding logic and undecidability, which is probably more a college level thing.

[femmocrat]

11. I was being "sarcastic".

There have been posts on DU criticizing the difficulty of the "new" math in Common Core. But thanks for trying to explain it.