Mathematical puzzles

Puzzles, situation puzzles and recreational mathematics.

situation puzzles and recreational mathematics. Neuron juice
 
 
 

Neuron juice.

The important thing is not to stop questioning. (Albert Einstein.)

  

Riddle. 6.- A prisoner is locked up in a cell that has two doors —one leads to death and the other one to freedom.

Each door is guarded by a watchman.

The prisoner knows that one of them always tells the truth and the other one always lies.

To choose the door, he can just ask a question to a watchman.

How can he save himself?

 

SOLUTION