Logic Puzzle

Let's break it down:

• Sally is a girl.
• She has 3 brothers.
• Each of her brothers has 2 sisters.

Now, think about the brothers' perspective:
Each brother is a sibling to Sally and shares the same siblings.

So, when it says each brother has 2 sisters, those are the girls in the family. Since Sally is one girl, and there are 2 sisters in total from the brothers' point of view, that means there must be one other girl besides Sally.

Therefore, Sally has 1 sister.

Answer: 1 sister ✅