Rajiv is the brother of Arun. Sonia is the sister of Sunil. Arun is the son of Sonia. In this family relation question, how is Rajiv related to Sunil?

Introduction / Context:
This problem gives a short chain of relations involving four people: Rajiv, Arun, Sonia and Sunil. The information connects who is a brother, who is a sister and who is a son. From this, we must decide how Rajiv is related to Sunil. The question is typical of blood relation problems in verbal reasoning, where converting sentences into a family tree quickly reveals the answer.

Given Data / Assumptions:
• Rajiv is the brother of Arun.• Sonia is the sister of Sunil.• Arun is the son of Sonia.• Standard assumptions about gender follow the statements.

Concept / Approach:
We start by placing Sonia and Sunil as siblings. Then we note that Arun is the son of Sonia, which makes Arun the nephew of Sunil. Next we use the fact that Rajiv is the brother of Arun. That means Rajiv is also a child of Sonia. As a result, Rajiv is another nephew of Sunil. Therefore, Rajiv is related to Sunil as nephew. The problem is solved by correctly tracking which generation each person belongs to and who is the parent of whom.

Step-by-Step Solution:
Step 1: Sonia and Sunil are siblings, with Sonia explicitly described as sister of Sunil.Step 2: Arun is the son of Sonia, so Arun is a child of Sonia and is in the next generation below her.Step 3: Since Sonia and Sunil are siblings, any child of Sonia is a niece or nephew of Sunil. Thus Arun is nephew of Sunil.Step 4: Rajiv is the brother of Arun.Step 5: Therefore Rajiv is also a child of Sonia, in the same generation as Arun.Step 6: As another child of Sonia, Rajiv is also a nephew of Sunil.

Verification / Alternative check:
If we draw a simple family tree, we put Sonia and Sunil on one horizontal level as siblings. From Sonia, we draw two children, Arun and Rajiv. Looking from Sunil downward, both of these children are nieces or nephews. Because Arun and Rajiv are male, each is classified as a nephew. No other standard relation such as brother or son fits without contradicting the data about who is parent and who is sibling.

Why Other Options Are Wrong:
Son of Sunil: For this to be true, Sunil would need to be the parent of Rajiv, but Sonia is clearly the parent of Arun and hence of Rajiv.Brother of Sunil: Brothers share parents in the same generation, but Rajiv is one generation below Sunil.Father of Sunil: That would require Rajiv to be one generation above Sunil, which is not the case.Uncle of Sunil: An uncle is a sibling of a parent, the reverse of the actual situation here.

Common Pitfalls:
Some candidates quickly see Arun is nephew of Sunil but then mistakenly think Rajiv, as a brother of Arun, might be a cousin of Sunil. This occurs when people do not carefully track who the parent is. As soon as we realise that Rajiv and Arun share the same mother Sonia, who is Sunil's sister, it becomes clear that both are nephews of Sunil.

Final Answer:
Rajiv is the nephew of Sunil.