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Answers: Peter and Paul are twin brothers.One of them(we dont know which) always lies.The another one always tells the truth.I ask one of them:
"Is Paul the one the lies?"
"Yes"he answers.
Did I speak to Peter or Paul

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There are four possibilities--

If Peter is the one who lies, and you asked Peter if Paul is the one who lies, he would lie and say yes.

If Peter is the one who lies, and you asked Paul if Paul is the one who lies, he would tell the truth and say no.

If Paul is the one who lies, and you asked Peter if Paul is the one who lies, he would tell the truth and say yes.

If Paul is the one who lies, and you asked Paul if Paul is the one who lies, he would lie and say no.

In both cases where the answer is "Yes," you're speaking to Peter.

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You spoke to Peter.

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Paul.

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Peter obviously, because you asked about paul

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Peter.

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This is definitely a trick question...........I'll say Paul.

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