On a logical reasoning problem

The meaning of this question is that P and Q are telling the truth, and no one is going to test anyone! ! It is through these truths that people analyze. Look at the answer at the back. Never mention the word temptation.

Because Mr. P only knew the number of cards at first and didn't know the color of the cards, he said he didn't know. Now it has been analyzed that it can only be red or square, not a, so he knows that it is Q, that is, red Q (it may also be grass Q before), and 4 and 5 are the same.

P said yes, and Mr. Q also knew that the number of points was Q, 4 or 5. If Mr. Q knows the number of flowers is red hearts, then he can't say that he knows it, because he is not sure whether it is 4 or Q. But if he knows that the color is square, he can be sure that it is square faster than 5, so he says he knows it, too.