The second paradoxe :

All in paradise

A man who has just died comes into a room where two doors are located.
One leads to heaven , the other to hell. In front of each door is a guard who can not say yes or no. The man knows that one of the two guards always lying and that the other always tells the truth .
But he does not know which ment which neither speaks the truth.
He is entitled to a single question. 

What should he ask for one of the two guards to find the door of paradise?

Solutions :

A sensible question is:

 "Let me answer the other guard if I ask him if he is at the door of paradise?" 

There is always exactly a lie in the response also:
If the answer is NO, paradise is the door the other guard (the one that is not questioned);

If the answer is YES, paradise is in front of the goalkeeper who was questioned.

Another Question proposed by Olivier a user is:

 "Is the liar Before Paradise?"

 If the answer is NO, Paradise is the gate behind the guard to whom the question was asked. 

 If the answer is YES, Paradise is the other door. 

Réponse Proposed by Bruno that we would a math teacher  English 

"If I had asked you which door to take five minutes earlier, which would you have told me?" The obvious benefit of this response is to implicitly speak twice on the same person. Thus two consecutive lies will cancel and two right answers will give a good answer.

 -The Liar lied and gave the wrong door. The second time, he clearly says the opposite of what he had said and finally show the correct door.

 -Celui Who is right, gives the right place every time. 

In both cases, we obtain directly the door of paradise. However, this interesting response was not acceptable because the two guards would know that answer YES or NO!