:rolleyes:
That’s what happens when typing rhythm overtakes pattern recognition…
First round:
If A has A, he knows that B has 2.
If A has K, he knows that B has Q.
If A has any other card, he doesn’t know what B has.
A answers “no”, and therefore has some card from the set {2,3,4,5,6,7,8,9,T,J,Q}.
Second round:
B cannot have any card from the set {2,Q} because A answered “no”.
If B has A, he knows that A has 2.
If B has K, he knows that A has Q.
B answers “no”, and therefore has some card from the set {3,4,5,6,7,8,9,T,J}.
Third round:
A cannot have any card from the set {A,2,Q,K} because B answered “no”.
If A has 3, he knows that B has 4.
If A has J, he knows that B has T.
A answers “no”, and therefore has some card from the set {4,5,6,7,8,9,T}.
Fourth round:
B cannot have any card from the set {A,2,3,4,T,J,Q,K} because A answered “no”.
If B has 4, he knows that A has 5 (else A would have said “yes” for 3)
If B has T, he knows that A has 9 (else A would have said “yes” for J)
If B has 5, he knows that A has 6.
If B has 9, he knows that A has 8.
Otherwise, A has 7.