Introducing a man, a woman said, "He is the son of my mother's brother's father's son." How is the woman related to this man?

Introduction / Context:
This is a layered blood relation riddle with several possessive steps: my mother's brother's father's son. Questions like this train you to carefully follow each link in the chain, simplifying it stage by stage into a familiar relation such as uncle, cousin or grandparent, and then answering the final relational question.

Given Data / Assumptions:

• The speaker is a woman.
• Her mother's brother is her maternal uncle.
• The father of that maternal uncle is the woman's maternal grandfather.
• The phrase that grandfather's son refers to a male child of the same grandfather.
• The man being introduced is the son of that male child.

Concept / Approach:
Start from my mother's brother, which is the woman's maternal uncle. His father is her maternal grandfather. The grandfather's son must be one of his male children, which includes the woman's maternal uncle and possibly her mother's brothers. In standard exam logic, the simplest read is that this son is the woman's maternal uncle. Thus the full phrase reduces to the son of my maternal uncle. The son of the woman's maternal uncle is her cousin. Therefore, the man is the woman's cousin, and she is his cousin as well.

Step-by-Step Solution:
Step 1: Identify my mother's brother as the woman's maternal uncle.Step 2: The father of that uncle is the woman's maternal grandfather.Step 3: The phrase my mother's brother's father's son refers to a son of the maternal grandfather.Step 4: The simplest consistent choice is that this son is the same maternal uncle.Step 5: So the man is described as the son of the woman's maternal uncle.Step 6: The son of a maternal uncle is a cousin of the woman.

Verification / Alternative check:
Draw a small tree. Put the maternal grandfather at the top. Under him place two children: the woman's mother and her maternal uncle. The maternal uncle has a son, who is the man in the question. From the perspective of the woman, that son is the child of her mother's brother, which is the standard cousin relation. This matches the derived chain and does not conflict with any stated information.

Why Other Options Are Wrong:
Son is wrong because the man is not described as the child of the woman.Brother would require both to share parents; here they share grandparents.Nephew is wrong because the man would then be one generation below the woman, which is not implied.Uncle is the opposite direction of the actual relation.

Common Pitfalls:
Many learners become confused at the step father's son and assume that it must represent the woman's father, which leads to incorrect conclusions. Others lose track of reference points and forget that all relational phrases start from the speaker, not the introduced man. Reducing the long chain to short, familiar pieces like maternal uncle and then cousin is the best way to avoid errors.

Final Answer:
The woman and the man are Cousins; the woman is his cousin.