Alright, let's tackle this problem step by step. The question is:
"Sally (a girl) has 3 brothers. Each brother has 2 sisters. How many sisters does Sally have?"
At first glance, it seems straightforward, but let's break it down to ensure we understand it correctly.
Understanding the Problem
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Sally's Siblings: We know Sally has 3 brothers. So, from Sally's perspective, she has 3 brothers.
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Each Brother's Sisters: The tricky part is the next statement: "Each brother has 2 sisters." We need to interpret what this means in the context of the siblings.
Analyzing the Brothers' Perspective
Let's think about what it means for one of Sally's brothers to have 2 sisters.
Counting the Sisters
Given that each brother has 2 sisters, and one of them is Sally, who is the other sister?
- This implies that apart from Sally, there is one more sister.
Let's name the siblings to visualize better:
- Let's say the siblings are: Sally, Brother1, Brother2, Brother3.
Now, from Brother1's perspective:
- His sisters are Sally and any other female siblings.
But we know Sally is the only other girl mentioned initially, but the statement says each brother has 2 sisters, which would mean there's another sister besides Sally.
So, let's add another sister, say Sister1.
Now, the siblings are: Sally, Sister1, Brother1, Brother2, Brother3.
Now, from any brother's perspective (let's take Brother1):
- His sisters are Sally and Sister1 — that's 2 sisters, which matches the given information.
Verifying the Count
Let's check:
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Total siblings: Sally (girl), Sister1 (girl), Brother1, Brother2, Brother3 (3 boys).
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Sally's brothers: Brother1, Brother2, Brother3 — that's 3 brothers, which matches.
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Each brother's sisters: Sally and Sister1 — that's 2 sisters, which matches the given information.
Potential Misinterpretation
Initially, one might think that since Sally has 3 brothers, and each brother has 2 sisters, and Sally is one of them, then the other sister must be another girl. But it's easy to overlook that the "other sister" is in addition to Sally, making the total number of sisters two (Sally and Sister1).
Some might误以为 the "2 sisters" each brother has are in addition to Sally, leading to more sisters, but that would contradict the initial count where Sally is the only sister mentioned at first. The correct interpretation is that the 2 sisters include Sally, meaning there's one more sister besides her.
Conclusion
After carefully analyzing the relationships:
Therefore, Sally has 1 sister.
Final Answer
Sally has 1 sister.
