Jack is looking at Anne, Anne is looking at George. Jack is married, George is not.
The question is…Is a married person looking at an unmarried person?
A. Yes
B. No
C. Cannot be determined
I got the answer right after thinking about it for a bit.
Spoiler contains the answer, but see if you can figure it out and reply with your answer without looking at the spoiler, looking up the answer, or reading other replies in here.
Bonus points if you can explain the reasoning behind your answer.
Answer:
[spoiler]
Yes.
Let’s say Anne IS married. In that case, it’s a yes, because a married person (ANNE) is looking at an unmarried person (GEORGE).
Let’s say Anne ISN’T married. Well, the answer is still the same: Yes, because in that case, a married person (JACK) is looking at an unmarried person (ANNE).[/spoiler]
If Ann we’re unmarried, then married Jack would be looking at an unmarried person. If Ann were married, then married Ann would be looking at an unmarried person.
My answer is yes. Because there are two possible marital states for Anne and both of them would lead to a married person looking at an unmarried person.
This raises an interesting point. I am a mathematician who uses classical reasoning and the answer is obvious. But a so-called intuitionistic mathematician cannot answer the question because the only answer he would find acceptable is one that tells which married person is looking at an unmarried person. In fact, what this does is to put a well-known mathematical example of this phenomenon into layman terms.
The mathematical version is this. Can an irrational number to an irrational power be rational? Yes (for a classical mathematicians). Consider (sqrt(2)^sqrt(2))^sqrt(2), which obviously is sqrt(2)^2 = 2. So if sqrt(2)^sqrt(2) were rational, that would be the example and if not it would be a rational number whose sqrt(2) power is rational. But I like the poster’s example better, because it is so accessible.
Several people have raised a valid point. The way the question is worded leaves a loophole.
[spoiler]The puzzle says George is not married. But it doesn’t explicitly state he’s a person. George could be a dog, for example - which would be in keeping with his unmarried state.
So if Anne is married, then there’s no married person looking at an unmarried person. Jack, a married person, is looking at Anne, a married person. And Anne, a married person, is looking at George, an unmarried dog.
So the correct answer is the “C. Cannot be determined”.[/spoiler]
Yip. I didn’t notice that either, but that is how to break the question.
I tried to find a contradiction, but there is nothing stated in the OP
that must be performed by a person–human or not. For example, no one “wants” anything–which would required anthropomorphism, making even iguana Anne a person for the sake of the puzzle. Looking is not even arguably a person-only trait. And people give names to non-persons all the time.
