Logic Puzzle

I need to figure out how many sisters Sally has.

Let me work through this step-by-step.

Given information:

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

Key insight: Sally's brothers are also Sally's siblings, so they share the same sisters. When we're told "each brother has 2 sisters," those sisters include Sally herself.

Working it out: If each brother has 2 sisters, and Sally is one of those sisters, then there must be 2 sisters total in the family (Sally + 1 other sister).

Answer: Sally has 1 sister.