Just got this from a friend. trying to verify my answer.
One day two students, Mr. P and Mr. Q are doing a test with Prof John.
They know there are 16 cards in the drawer,
Heart: A Q 4
Spade: J 8 4 2 7 3
Club: K Q 5 4 6
Diamond: A 5
Prof John drew one card from the group. He told Mr. P the face value of the card and told Mr. Q the suite of the card.
Here is the conversation between them,
Prof John: Do you know which card it is?
Mr. P: I cannot tell which card it is.
Mr. Q: I know you cannot tell.
Mr. P: Based on what you just said, I know which card it is now.
Mr. Q: Well, I also know which card it is now.
What is the card and give your reasoning.