I'm working on this propositional logic question and I did not understand the book answer at all. The book says the hostess knows to bring back two drinks for the first two professors.
When three professors are seated in a restaurant, the hostess ask them, "Does everyone want coffee?" The first professor says, "I do not know." The second professor then says, "I do not know." Finally, the third professor says, "No, not everyone wants coffee." The hostess comes back and gives coffee to the professors who want it. How did she figure out who wanted coffee?
