I Was Told There Would Be No Math

B

B

This would be even better if option C was 0%

No way would it B, 50%

You have a 1 in 4 chance, 25%, of selecting B.
Likewise, you couldn't pick A or D since you have a 2 in 4 chance, 50%, of selecting the same answer.
And C is a non-issue.
Therefore, options A, B, C and D are all incorrect.

I think the only way to answer the question correctly is to answer it directly.
"If I chose A, B, C or D as an answer to this question at random, the chance that I would be correct is 0%"

But I do like the idea of changing C to 0% too!

Mathematical paradox!

Landrew is right. There is no right answer.

In first A is correct, if a is correct then D is correct too. If only one question is correct, and A and D is correct then ofcourse B should be correct. And then if A, D and B is correct, and only one answer is correct then C is correct because A, D and B couldnt. Huh.... wait if A, D and B is correct and couldnt be correct then D should be 75% if it should be correct.

Conclusion: if A, D and B is correct, and couldnt because only one answer is correct then C is correct. But couldnt because 60% is wrong. Because C should be 75%.
But if C be 75% (not 60%) then this answer is wrong too, because the chance is less probably that this be chosen.

Conclusion of conclusion: In this aspect A, D, B and C (if it be corrected to 75% (maybe)) are correct answer, but not because only one is correct, then 0% is correct. But isnt because not exist that answer, and we must chose one answer.

Here is a good explanation of what this is all about:
http://www.reddit.com/r/reddit.com/comments/jurc9/a_multiple_choice_question/c2fazpw

1. I think the key words to solving this puzzle are "If," "random." It doesn't tell you to select an answer randomly, it just says "if." Just to restate it more plainly, I am not selecting an answer at random.

2. The probability of choosing the right answer at random for ANY multiple choice question with 4 choices is 1-in-4 or 25%. That is for "any" multiple choice question, not specifically "this" question. Yet this question ask only about this question. This is where the confusion lies.

3. In this question, the probabilities are given as the answers to the question, and two answers are 25% which is the correct probability for any "normally" constructed multiple choice question, giving the probability of selecting the "%25" as the answer for THIS question 2-in-4.

Therefore, if I were to randomly select an answer the probability that I would land on A or D would be %50. Yet since I am NOT randomly selecting the correct answer is B.

I'm So Meta, Even This Acronym

PS did this make sense to anyone else but me?

Add E) All of the above

How about a nice game of chess?

the version of this that i have seen has 0% instead of 60%

It surprised me how many people commenting above totally missed the point.

Hey Samuel,
What you said seems to make sense. I think you bring up an important point about randomness or single-blind selection.
I'm having second thoughts on my previous answer. When considering "Schrodinger's Cat" (and maybe "The Monty Hall Effect" applies here too), I think maybe A or D is correct.
Let me throw this at you...so, if I didn't know what the values for A, B, C and D were and randomly picked A (to exclusion and without knowledge of B, C and D's values) then A would be correct since my 1-4 chance of randomly selecting a the correct answer of 25% is right. Likewise, if my first and only pick was D (to exclusion and without knowledge of A, B and C's values) then I would be right for the same reason. To the extreme, pretend A, B, C and D all had a value of 25%, but of course I don't this because it is a random selection then regardless of which letter I picked I would be right. I have a 1 in 4 choice to make the right selection (let's continue to pretend they are all 25% and I chose C). As long as I don't know what the answers are then until those other answers are revealed to me they could be every possible answer from 0% - 100%,"none of the above," "False," "Blue," a random word from the dictionary or even BLANK.
So, if I randomly chose C and it is 25% then what are the chances that A, B or D would also be 25% when they could hold ANY value? Almost 0%. Better chances winning the lottery.

The problem with this question is that we know what we shouldn't. One cannot randomly select an answer when they know in advance what the answers are.

I can see B being correct if I knew the values for A, C and D beforehand. But if I know that there are two 25% answers, then that knowledge would remove the random element that the question requires which you noted.

Have I made it more confusing? hahaha

Jolly,

Share the point.

It is a simple multiple choice question. If you answer the question given it is B no matter how you see it and samuel is correct with his explanation. Everyone else saying it is A, B or D are just over complicating things. What ever happened to KISS?

Devious. I love it.

That's the problem Josh. How you see it is at issue. You're picking B because you know what A, C and D are. That means you are not "choos(ing) an answer to this question at random."

The biggest mistake I'm seeing here is people assuming that one of the answers must be correct. None of the answers are correct, it's a logical (or mathematical) paradox.

Basically to begin you assume one answer is correct (eg A or D) and then evaluate it. It proves to be false but suggests another answer to be true (B), however evaluating that answer proves to also be false and suggests the first is true, which we already know is false. Thus, we have a paradox.

The remaining answer, C) is just filler.

Those who suggest that if answer C) was 0% then they would choose that are also incorrect. If C) was 0%, then the chances of picking C) would be 25% and then you're back into the vicious cycle of the paradox :P

Samuel and Josh are wrong.

Assume the correct answer is 25%. Then A and D are correct, so your chance of randomly guessing the right answer is 50%, which contradicts our initial assumption. That assumption leads to a contradiction.

Assume the correct answer is 50%. Then B is correct, so your chance of randomly guessing the right answer is 25%, which also contradicts our initial assumption. That assumption also leads to a contradiction.

(By the same reasoning 0% is also not the correct answer).

Hence none of the available answers are correct.

A simpler version of the same paradox:

Will you answer to this question be "No"?
A. Yes.
B. No.

Nicely truncated Logical. Thanks

But Logical, the question says "If you choose an answer at random," it doesn't say that you MUST choose an answer at random. It is only a theoretical question that leads to the actual question. Therefore, the answer is B.

If i was a teacher i'd give a multiple choice test where all the answers (but one) were B. The last question would be True False, "Is every answer on this test (B)". Just to blow there minds.

inconcibable!

Doho! Inconceivable.

Use a non-uniform random distribution. Like, say, flip a coin with heads assigned to B, and a die roll if you get tails to pick between A, C and D.

Logical has the best explanation, I think.

It's always interesting to see explanations from people who don't understand, trying to justify their answers though.

Miss Cellania: It's a paradox. That's why it's funny. It can't be "B" and "A" at the same time as they are 2 different values. You gotta pick one. If it's "B", then it's 50%, which makes it not 25%....get it? Paradox.

How do know so much about swallows?

...and the next morning Pinocchio wakes up and immediately the first thing he says to Geppetto is "My nose is growing now."

What would happen?

@misssunshine Well, you have to know these things when you're a Neatorama blogger you know.