Question

2. (5 points) A very special island is inhabited only by knights and knaves. Knights always tell

the truth, and knaves always lie. You meet two inhabitants: Sue and Marge. Sue says that
Marge is a knave. Marge claims. "Sue and I are not the same." Determine who is a knight and
who is a knave.

Answer 1

• Sue is knave and Marge be knight

Explanation:

Let Sue be knight and Marge be knave.

Sue says: "Marge is a knave". Since Sue is knight, she is right and Marge should lie.

Marge says: "Sue and I are not the same." - this is right answer too, so this is not a correct response and our assumption is wrong.

Now, let Sue be knave and Marge be knight. Then Marge's response is right and Sue's is wrong. This is a match and this assumption is correct.