Logic Puzzle

Let's break down the problem:

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

Let's name the siblings:

• Sally (girl)
• Brother 1
• Brother 2
• Brother 3

Now, the key: Each brother has 2 sisters.

Since Sally is one of the sisters, let's see if there are more:

Suppose there is only one girl (Sally) in the family.

• Then each brother would have only 1 sister: Sally.
• But the problem says they have 2 sisters each.

Thus, Sally must have one sister (since the brothers must have 2 sisters). Let's call this other sister "Anna".

So the siblings are:

• Sally (girl)
• Anna (girl)
• Brother 1
• Brother 2
• Brother 3

Now, each brother has 2 sisters: Sally and Anna.

So, how many sisters does Sally have?

• Sally's sisters = 1 (Anna).

Final Answer:

Sally has 1 sister.