A family has 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. In this family, how is Q related to X?

Introduction / Context:
This question is a structured family relation puzzle. Six members of a family are linked by statements about marriage, parenthood and sibling relationships. The specific task is to find out how Q is related to X. To solve this type of problem, we must place each member in the correct generation and family position, then read off the required relationship.

Given Data / Assumptions:
• Q is the son of R, but R is not the mother of Q.• P and R are married.• Y is the brother of R.• X is the daughter of P.• Z is the brother of P.• There are no additional hidden relationships.

Concept / Approach:
The statement that Q is the son of R and R is not the mother of Q means that R must be the father of Q. Since P and R are a married couple, P becomes the mother of Q. X is stated to be the daughter of P, so X is another child of P and R. That makes Q and X siblings, with Q being the brother and X the sister. Therefore Q is related to X as brother. Recognising R as the father and P as the mother is the central step.

Step-by-Step Solution:
Step 1: Q is son of R and R is not mother, so R is the father of Q.Step 2: P is married to R, so P is the spouse of R.Step 3: Since Q is child of R, and P is R's partner, P is naturally the mother of Q.Step 4: X is daughter of P, so X is also child of P.Step 5: This means X and Q are both children of the same couple P and R.Step 6: Two children of the same parents are siblings, and since Q is male, he is the brother and X is the sister.

Verification / Alternative check:
A simple tree has parents P and R in the middle generation. They have at least two children, Q and X. Y is brother of R, so he is an uncle to Q and X. Z is brother of P, so he is another uncle. None of this changes the fact that Q and X share both parents. The only consistent relationship between them is that of brother and sister. Q cannot be father, husband or cousin of X while still fitting all the given conditions.

Why Other Options Are Wrong:
Husband of X: For this, X and Q would be spouses, but the data clearly makes them children of the same parents.Father of X: Q is in the same generation as X, not one generation above.Uncle of X: An uncle would be a brother of a parent, whereas Q is the child of the parents.Cousin of X: Cousins are children of siblings, not children of the same parents.

Common Pitfalls:
Some candidates wrongly imagine that the couple mentioned may have separate sets of children and treat X and Q as cousins. Another error is to overlook the phrase R is not mother of Q and not interpret R as father. A disciplined reading that first fixes who is father and who is mother and then identifies all children usually prevents these mistakes.

Final Answer:
Q is the brother of X.