Question

  1. Alice, Bob, and Charlie make the following statements:

    Alice: Bob is lying.
    Bob: Charlie is lying.
    Charlie: 1 + 1 = 2.

    Who is telling the truth? Who is lying? Explain your answer.

  2. Now Alice, Bob, and Charlie make the following statements:

    Alice: Bob is telling the truth.
    Bob: Alice is telling the truth.
    Charlie: Alice is lying.

    What are the possible numbers of people telling the truth? Explain your answer.

  3. They now make the following statements:

    Alice: Bob and Charlie are both lying.
    Bob: Alice is telling the truth or Charlie is lying (or both).
    Charlie: Alice and Bob are both telling the truth.

    Who is telling the truth and who is lying on this occasion? Explain your answer.