Four logicians are at a cafe together,
The waiter asks "Would you all like some coffee?"
The first logician say "I don't know",
the second logician say "I don't know",
the third logician say "I don't know",
the forth logician say "no, thank you".
The waiter understands and writes down the order.

How many coffees are made, who are they for, and why?

Question

Four logicians are at a cafe together, 
The waiter asks "Would you all like some coffee?"
The first logician say "I don't know",
the second logician say "I don't know",
the third logician say "I don't know",
the forth logician say "no, thank you".
The waiter understands and writes down the order.

How many coffees are made, who are they for, and why?

anonymous · Answer

3 coffees

anonymous · Answer

The first 3 want a coffee individually, that is why they didn't say no.

parthkohli · Answer

Yup!  I've heard this as a math joke.