GO Classes 2023 | Weekly Quiz 3 | Question: 12

Answer 1

Assume $A$ is knight then $B$ is also knight But now according to $B$, “The two of us are opposite types” should be true But it is Not true.
So, $A$ is knave, so, according to $A$ “$B$ is a knight”, should be a lie, so $B$ is knave.

Answer 2

Knights : x : TRUE wala.

Knaves : y: FALSE wala.

A: “B is x” 

B: “Opposite”

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Option A : 

A is x & B is x?

As A is x: which means he is true → B is x

As B is given/proven to be x → A must be y: CONTRADICTION: HENCE OPTION A IS FALSE

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Option B : 

A is x & B is y?

As A is x: which means he is true → B is x: CONTRADICTION: HENCE OPTION B is also FALSE

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Option C : 

A is y & B is y?

A is y → which means A is false → B is y

B is y → which means B is false → A is y 

HENCE TRUE

Comments

@Deepak Poonia sir : Please confirm this.

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@Udhay_Brahmi

It’s correct But making two cases is more efficient. Being efficient is also important.