Ok, just saw slacdemic's problem and decided to work on it. I'm not sure if this is right or wrong but here's a shot. A, B, C are the three guys. By now, we all know that everyone is raising their hands. But then, B, being a smart one, thinks, if I were wearing a black hat, A or C would have realized they are wearing a red hat because A and C woud see that B has a black hat on and that they are raising hands because they see the red hat on each other. However, B sees that everyone is raising hands and noone has claimed they have a red hat on, so if they're smart (unlike us :D) they will probably all say "I have a red hat on!" together. :D. Is that right slackdemic?