Mathur's uncle's daughter's brother is Salim. How is Salim related to Mathur?

Introduction / Context:
This is a straightforward blood relation question involving uncle, daughter and brother. The goal is to understand the chain starting from Mathur, going through his uncle, then that uncle's daughter and finally her brother, Salim. The test checks whether you can correctly interpret how children of uncles and aunts are related to you.

Given Data / Assumptions:
- Reference person: Mathur. - Mathur has an uncle. - That uncle has a daughter. - The daughter has a brother named Salim. - All relationships are by blood, and uncle is a brother of one of Mathur's parents.

Concept / Approach:
Children of your uncle or aunt are your cousins. The uncle's daughter is clearly Mathur's cousin (female), and her brother is another child of the same uncle. That makes Salim also a cousin (male) of Mathur. The question wants the relationship of Salim to Mathur, so we must express it from Salim's point of view or from Mathur's, using the standard term cousin.

Step-by-Step Solution:
Step 1: Mathur's uncle is a brother of Mathur's father or of Mathur's mother. Step 2: The daughter of Mathur's uncle is a child of that uncle, so she is Mathur's cousin. Step 3: Salim is the brother of that daughter, which means he is another child of the same uncle. Step 4: Therefore, Salim is also a child of Mathur's uncle. Step 5: Any child of your uncle or aunt is your cousin. Hence, Salim is Mathur's cousin.

Verification / Alternative check:
You can draw a small family tree: place Mathur's grandparents at the top, then his parent and his uncle as siblings on the second level. On the third level, place Mathur as the child of his parent and the uncle's two children: the daughter and her brother Salim. All three on this level are grandchildren of the same grandparents, with different parents. This is exactly the pattern of first cousins.

Why Other Options Are Wrong:
- Son: For Salim to be Mathur's son, Mathur would need to be in the generation above Salim, which is not the case. - Brother: A brother shares at least one parent with you; Salim shares a grandparent but not a parent with Mathur. - Father: There is no indication that Salim is older and the parent of Mathur. - Uncle: An uncle would be a brother of a parent or the husband of an aunt, not a child of an uncle.

Common Pitfalls:
A common mistake is to confuse uncle's daughter with sister, especially when drawing quick diagrams. Another error is to misread the chain and treat uncle's daughter's brother as a more distant relation. Remember that both the daughter and her brother are simply children of the same uncle, and therefore both are cousins. Carefully tracing who the parents are at each step avoids these mistakes.

Final Answer:
Salim is Mathur's cousin.