Three logics, one simple question and three answers. The last one is a categorical “yes” — although no one has said anything directly to him.
The three logicians in the bar
Riddle statement
A waiter approaches a table where there are three logicians and asks them:
“Do you three want beer?”
The first one answers:
“I don't know.”
The second one answers:
“I don't know.”
The third party answers:
“Yes.”
Why can you say this with certainty?