A very special island is inhabited only by knights and
knaves. Knights always tell the truth, and knaves always lie.
You meet four inhabitants: Usha, Eesha, Nisha and Asha.
Usha tells you ‘Eesha is a knave’. Eesha tells you ‘Asha is a
knave’. Nisha claims,
‘Eesha is a knight and Asha is a knave.
’. Asha tell you,
‘I and Nisha are different.’
Identify the knave(s)
Answers
Here's your answer
Let's assume that Nisha is a knight
This means that Nisha isn't lying and Eesha is a knight as well. Therefore, Nisha and Eesha are knights.
Usha is a knave as she is lying about Eesha being a knave.
According to Nisha and Eesha, Asha is a knave, that means Asha must be lying. Asha says that she is different from Nisha which should be a lie, but Eesha and Nisha also support this theory by saying that Asha is a knave.
Thus contradiction arises and we can safely regard the assumption of Nisha being a knight as false.
Now that we know Nisha is not a knight, we can conclude that she is a knave.
This means that Nisha is lying.
This means that Nisha is lying. Thus we can conclude that Eesha is not a knight but a knave (as Nisha always lies) and Asha is not a knave but a knight.
Since Usha hadn't been lying about Eesha being a knave, we know she doesn't lie and thus is a knight.
Therefore,
✓Knights===== Asha and Usha
✓Knaves===== Eesha and Nisha