The point isn't in what someone sees, the point is in what someone doesn't see. C knows that his hat is either white or blue. Now, let's say that C's hat is white. That means that A sees a white and a blue (because we know B's hat is blue). A can't make any decisions, for the very reason you stated.

So, let's see what B thinks. (Remember, C's hat is white at this moment, and that A didn't do anything.) Since A didn't do anything, B knows his hat cannot be white. (If B's hat was white and C's hat was white, A would say his hat is blue.) So, B knows that his hat must be blue.

But, B doesn't do anything, either. So, since A didn't stand up and B didn't stand up, then C must be able to stand up because his hat isn't white.

Does that make sense?

------
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In reply to Re: Re: (OT) Meditate on this brain-teaser by dragonchild
in thread (OT) Meditate on this brain-teaser by japhy

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