A lady said to a man, "Your father's wife is the only sister of my brother". How is the man related to the lady?

Son

The correct answer is Option (4) → Son

Let’s decode the statement step by step.

“Your father’s wife is the only sister of my brother.”

• “My brother’s only sister” → that sister is the lady herself
• So, your father’s wife = the lady

This means the lady is the wife of the man’s father, i.e., his mother.

Therefore, the man is the son of the lady.