4
What is the question?
David has one of the numbers 1, 2, or 3 in mind. Ruth is allowed to ask one question to find out which of these three numbers he has in mind. David will answer only "yes", "no", or "I don't know". Which question should Ruth ask David to find out in one time which number he has in mind?
Ruth could for example ask David the following: "I have the number 1 or 2 in mind. Is the number that you have in mind larger than the number I have in mind?" The answer "yes" means that Martin has the number 3 in mind, "I don't know" means that he has number 2 in mind, and "no" means that he has number 3 in mind.
What is the question?
David has one of the numbers 1, 2, or 3 in mind. Ruth is allowed to ask one question to find out which of these three numbers he has in mind. David will answer only "yes", "no", or "I don't know". Which question should Ruth ask David to find out in one time which number he has in mind?
Ruth could for example ask David the following: "I have the number 1 or 2 in mind. Is the number that you have in mind larger than the number I have in mind?" The answer "yes" means that Martin has the number 3 in mind, "I don't know" means that he has number 2 in mind, and "no" means that he has number 3 in mind.
View Solution