A family consists of six members P, Q, R, X, Y and Z. Q is the son of R but R is not the mother of Q. P and R are a married couple. Y is the brother of R. X is the daughter of P. Z is the brother of P. Who is the father of Q?

Introduction / Context:
This question is set in the same six member family used in other problems and focuses on a single detail: determining who the father of Q is. The wording "Q is the son of R but R is not the mother of Q" is designed to make you think carefully about the gender of R.

Given Data / Assumptions:

• Family members: P, Q, R, X, Y and Z.
• Q is the son of R.
• R is not the mother of Q.
• P and R are a married couple.
• Y is the brother of R.
• X is the daughter of P.
• Z is the brother of P.
• We assume that in a married couple one is male and one is female.

Concept / Approach:
The central idea is that if Q is the son of R, then R is a parent of Q. The statement that R is not the mother rules out the female parent role. Therefore, R must be the father. Since P and R are a married couple, P becomes the mother. This logic directly answers the question.

Step-by-Step Solution:
Step 1: From "Q is the son of R", we know Q is a male child of R.Step 2: The next statement, "R is not the mother of Q", tells us that R is not the female parent of Q.Step 3: Since R is not the mother but still a parent of Q, R must be the father of Q.Step 4: P and R are a married couple, so if R is male, P must be female and hence Q mother.Step 5: The question asks, "Who is the father of Q?" From the reasoning above, R is clearly the father.

Verification / Alternative check:
Imagine names. Let R be Raj and P be Preeta. If Q is the son of Raj, and Raj is not the mother, Raj must be the father. Preeta then becomes Q mother as Raj wife. Other relatives Y, X and Z help complete the family picture but do not change this basic parent child relationship. The answer remains that Raj, that is R, is the father of Q.

Why Other Options Are Wrong:
P cannot be the father because P is the spouse of R and must take the other gender role, which is the mother. Z is the brother of P, and Y is the brother of R, so both belong to the parental generation but are not parents of Q according to the information given. "None of these" is incorrect because we have a clear and specific person, R, who fulfils the father role.

Common Pitfalls:
Some learners misinterpret "R is not the mother of Q" as suggesting R might not be a parent at all, but the first part of the sentence firmly declares R as the parent. Another mistake is to focus on extra details like Y and Z and overcomplicate the question. In such cases it helps to extract only the lines that directly involve Q and R and solve from there.

Final Answer:
Q father is R.