Logic Puzzle

1

Explanation

The reasoning starts by establishing the family structure based on the given information. Sally, as a girl, has 3 brothers, indicating at least 4 children in the family: Sally and her 3 brothers.

Next, the statement that each brother has 2 sisters is analyzed. Since Sally is one sister to each brother, an additional sister is required to account for the second sister per brother.

This leads to a total of 5 children: Sally, 1 other sister, and 3 brothers. In this configuration, each brother has exactly 2 sisters (Sally and the other sister).

From Sally's viewpoint, she has 3 brothers and shares the family with 1 other sister, confirming she has 1 sister. This structure satisfies all conditions without requiring additional siblings.