A king was asked by his ministers to give another chance to a mute prisoner who had been sentenced to death.
The king took a jar that was glued to a table.
He put two marbles in it.
One of the marbles was supposed to be black, and the other was supposed to be blue.
The king announced that if the prisoner picked out the blue marble, he would be freed; however, if he picked out the black marble, he would be executed.
The mean king wickedly placed only two black marbles in the jar and no blue marbles.
The prisoner witnessed the king putting only two black marbles in the jar.
Since the jar was not transparent, and it was glued to the table, how did the prisoner, who could not speak, escape with his life?