Logic

# Truth Tellers and Liars: Level 2 Challenges

John tells the truth on Mondays, Thursdays, and Saturdays, but lies on all the other days of the week.

One day he said, “I will tell the truth tomorrow.”

On which day of the week did he make this statement?

Only one of the following statements is true. Which one?

1) Statement 2 is true.
2) Statement 5 is false.
3) All five statements are true.
4) All five statements are false.
5) Statement 1 is false.

Knights always tell the truth and Knaves always lie.

In a group of six people, the following statements are made:

• Alice says, "None of us are Knights."
• Bob says, "Exactly two of us are Knights."
• Cathy says, "At least three of us are Knights."
• Dave says, "At most three of us are Knights."
• Evelyn says, "Exactly five of us are Knights."
• Frank says, "Exactly one of us is a Knight."

How many Knights are there?

An island has only two types of people: Knights (who always speak the truth) and Knaves (who always lie).

I met two men who lived there and asked the taller man "Are both of you Knights?".
He replied with a "Yes" or "No", but from his answer, I could not figure out what type of person each man was.
I then asked the shorter man "Is the taller man a Knight?".
He replied with a "Yes" or "No", and after that I knew which type of person each man was.

Were the men Knights or Knaves?

On one side of the card it is written that
"The statement on the other side of this card is true"

And on the other side it is written that
"The statement on the other side of this card is false"

Which statements is/are true?

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