Riddles are fun...

[flintlock]

The Plane question was so much fun, I figured we should try another. Again, I have an opinion, but I can't prove it and I was wrong last time so I'm keeping it to myself this time... for now. It came to me in an e-mail and I could only get it here in the form of a .jpg. It says it requires math and the only thing I'm worse at that CS, is math. I suspect you do need some to prove this, but I'll let the smart guys prove it.

Without further ado...

[WolbEm]

C has the best odds. A, B and D all have a 1:1 chance of guessing right becuase they either see nothing or see that 1 of each color is being used.   C has a 2:1 chance of guessing black and being right.

[Belgian rofls]

C has the best odds. A, B and D all have a 1:1 chance of guessing right becuase they either see nothing or see that 1 of each color is being used.   C has a 2:1 chance of guessing black and being right.

^Absolutely correct^

                         '_'

[xTc the NJ GUIDO]

Alright then here we go...

In a world where 1 is 2, 5 is 5, and 8 is 7, what do you get when you multiply 331 and 3 without heaven and earth?

[HongKongPhooey]

I would say D.  It says you cannot see through the wall but it doesn't state that you cannot see around it.  The picture Flint posted just shows a sectional view but it doesn't mean that they are actually in a straight line.  A plan view shows the likely orientation on A, B, C & D.

[Privateer]

i think hong's approach is the logical choice

Drop has the math portion of it down

[flintlock]

Sure the problem doesn't state D can't see A, but by having the wall, I would assume that was the objective, to prevent B, C and D from seeing A. It doesn't talk much about A at all actually so I don't know why, according to you drawing Hong, you would also assume B and C can't see A.

As for Dropkick's answer, the key to the whole question is, who should speak up and how can he be 100% sure he's right. 2:1 odds are better that 1:1 odds, but it's not 100%.

[Cole]

sweet flint. The class I was taking last semester directly addressed such problems.  I will take a look at it, and reply later.  I was supposed to go to work today, but my car battery is dead!?!?  go figure.

[WolbEm]

i forgot that bad guys are stupid. WTG Hong. 

[Cole]

The answer is C.  There are no odds.  It is just based purely on logic.  If you run the numbers, they all have the same probability of guessing.  However,

If D saw two of the same color, he'd be certain of the answer, answering right away.  Since he doesn't do this, C knows that his hat and the guy in front of him don't have the same color hat.  Thus, with 100% certainty, C will guess the opposite of the hat in front of him and be correct.

There you go.

[flintlock]

Correct!

Did you check your notes first?

[Cole]

nope.  you gotta give a harder one than that!

lol.

Like one where I need to use markov chains.  Ah, markov chains.  At least i understand that more than chebychev polynomials.  Man, those Russians are freakin complicated.

[WolbEm]

Just to stir things up...

Cole's answer is specious.  C cannot be 100% certain based on D's non-response, because there are still unknowns.   D could be deaf, dumb, blind, asleep, dead or just panicked with fear. C has no way of eliminating these possibilities since he cannot communicate with or see D.   Either Hong's layout is correct and D can see all and be certain, or C has a 2:1 odds at best.

Lisa: "I have a magic rock that keeps away tigers."
Homer " Really ?!?"
Lisa: "Sure, you dont see any tigers around do you?"
Homer: "Lisa, I would like to buy that rock"

 

[Cole]

i see we need to have lawyers write down these riddles for you.

I'm correct and the logic is infallible.

That the men are of reasonable intellect is a given.  otherwise it IS a trick question.

If the walls are set up as in hong's scenario, it IS a trick question.

If you were going to die, and saw the two black hats in front of you, would you just keep your mouth shut cause it's funny?

This is not a trick question, but a very answerable exercise in logic.

[WolbEm]

Cole  - I just enjoy pissing you off 

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