User:CenturionZ 1/Sandbox

My Sandbox

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God, Devil, Man: A Logic Problem

Problem

Three people are standing in a line in front of you:

• One of them is an incarnation of God. He knows everything, and always tells the truth.
• One of them is an incarnation of the Devil. He knows everything, and always lies.
• One of them is Man. He knows nothing, and answers randomly.

You can ask a total of three questions that can correctly be answered with yes or no, each to one of the persons. You may choose whom to ask.

Determine, with complete certainty, who is who...

Hint

You must use the fact you are allowed to change a question or the person to whom you ask a question depending on the answer to a previous question.