Kha-kha is an obscure island which is inhabited by two types of people: the "Yes" type and the "No" type. A native of type 'Yes' asks only questions for which the correct answer is 'Yes', while those of type 'No' ask only questions for which the correct answer is 'No'. For example, the 'Yes' type will ask questions like "Is 2 plus 2 equal to 4?" while the 'No' type will ask questions like "Is 2 plus 2 equal to 5?". The following question is based on your visit to the island Kha-kha.
Kevin and Kumar are brothers from the island. Kumar asks you, "Is at least one of us of type 'No'?" You can conclude that _____.
We must test the two possibilities for Kumar's type, based on his question: "Is at least one of us of type 'No'?"
A 'Yes' type always asks a question whose true answer is "Yes." Therefore, the statement "at least one of us is of type 'No'" must be true. Since we assumed Kumar is 'Yes', this forces the conclusion that Kevin must be 'No'. This scenario is logically consistent.
A 'No' type always asks a question whose true answer is "No." Therefore, the statement "at least one of us is of type 'No'" must be false. The only way for this to be false is if both of them are 'Yes' types. This, however, contradicts our initial assumption that Kumar is a 'No' type. This scenario is a logical impossibility.
Conclusion: The only logically consistent possibility is Case 1.
Final Answer: The correct option is A (Kumar is 'Yes' and Kevin is 'No').
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