When I ask ChatGPT (GPT4) I got the below answers (I regenerated for a total of 5 responses, it was correct 3/5 of them.) I'm not sure exactly how the regeneration works, if they're vanilla or if there is some trick to try to add different-ness to the answers. If it's the latter, it might be important that it got it right the first two times.
> Sally is the common sister to all three brothers. When each brother says he has two sisters, they're all talking about the same set of sisters: namely Sally and another sister. So Sally has one sister. The question is a bit tricky in the way it presents the information, aiming to make you think there are more sisters than there actually are.
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> Sally is the girl in question, and she has 3 brothers. Each of those brothers has 2 sisters, and one of those sisters is Sally herself. So, if you exclude Sally, then there is only one other sister. So, Sally has just one sister. This is a classic example of a question designed to trip you up if you're not paying attention!
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> Sally has no other sisters. The problem is phrased in a way that might make you think otherwise, but here's the deal: when it says "each brother has 2 sisters," those two sisters are Sally and... well, Sally again. Basically, each brother is counting Sally as one of their two sisters. There aren't additional sisters lurking in the background. So, Sally is an only sister with 3 brothers.
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> Sally has 3 brothers, and each of those brothers has 2 sisters. The tricky part here is not to overthink it or double count. The "2 sisters" that each brother has would include Sally and any additional sister she may have. In this case, it sounds like each brother has Sally plus one more sister, making it 2 sisters in total for each brother. Sally herself has just the one sister.
> So, to answer your question: Sally has 1 sister.
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> Sally has 0 sisters. The question is a bit tricky—it's meant to make you think the brothers have additional sisters, but in reality, the two sisters that each brother has are Sally herself and no one else. So, Sally doesn't have any sisters; she only has 3 brothers.
> Sally is the common sister to all three brothers. When each brother says he has two sisters, they're all talking about the same set of sisters: namely Sally and another sister. So Sally has one sister. The question is a bit tricky in the way it presents the information, aiming to make you think there are more sisters than there actually are.
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> Sally is the girl in question, and she has 3 brothers. Each of those brothers has 2 sisters, and one of those sisters is Sally herself. So, if you exclude Sally, then there is only one other sister. So, Sally has just one sister. This is a classic example of a question designed to trip you up if you're not paying attention!
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> Sally has no other sisters. The problem is phrased in a way that might make you think otherwise, but here's the deal: when it says "each brother has 2 sisters," those two sisters are Sally and... well, Sally again. Basically, each brother is counting Sally as one of their two sisters. There aren't additional sisters lurking in the background. So, Sally is an only sister with 3 brothers.
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> Sally has 3 brothers, and each of those brothers has 2 sisters. The tricky part here is not to overthink it or double count. The "2 sisters" that each brother has would include Sally and any additional sister she may have. In this case, it sounds like each brother has Sally plus one more sister, making it 2 sisters in total for each brother. Sally herself has just the one sister.
> So, to answer your question: Sally has 1 sister.
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> Sally has 0 sisters. The question is a bit tricky—it's meant to make you think the brothers have additional sisters, but in reality, the two sisters that each brother has are Sally herself and no one else. So, Sally doesn't have any sisters; she only has 3 brothers.