Solving the Family Relations Question

Let's carefully analyze the information provided about the family of four persons with only one child to determine the relationship between C and D.

We are given the following clues:

• There are exactly four persons in the family.
• There is only one child in this family.
• B is A's wife. This statement establishes that A and B are a married couple. Since B is the wife, B is female and A is male.
• B is D's daughter. This means that D is the parent of B.
• C is A's daughter. This tells us that C is the daughter of A. Since B is A's wife, C is also the daughter of B.

Identifying the Family Members and Their Roles

From the clues, we know that A and B are the parents and C is their daughter. Since C is the only child in the family, A and B are the only parents. This accounts for three people: A (parent), B (parent), and C (child).

The question states there are four persons in the family. Since C is the only child, the other three people (A, B, and the fourth person) must be adults. We already know A and B are adults.

The fourth person must be D. Since B is D's daughter, D is a parent of B. As B is a parent of C, D must be a grandparent of C.

So, the four members of the family are A, B, C, and D, where:

• A is a parent (male).
• B is a parent (female) and A's wife.
• C is the only child (female).
• D is a grandparent (parent of B, therefore either A's father-in-law or mother-in-law). D must be one of the four persons in the family.

Determining C's Relationship to D

We need to find out how C is related to D. Let's trace the relationships we've established:

• C is the daughter of B.
• B is the daughter of D.

Putting these two facts together, C is the daughter of the person who is the daughter of D.

Therefore, C is the daughter's daughter of D.

Understanding the Relationship

This relationship means that D is the parent of C's mother (B). This makes D the maternal grandparent of C. The question asks for C's relationship to D, which is that C is the granddaughter through the maternal line, or specifically, the daughter's daughter.

Revision Table: Key Relations in Blood Relations

Additional Information: Solving Blood Relation Questions

Blood relation questions are common in reasoning sections of exams. To solve them effectively:

• Read the statements carefully, one by one.
• Identify the genders of individuals where specified (e.g., wife, husband, son, daughter).
• Draw a family tree or diagram to visualize the relationships. Use symbols for gender (e.g., circle for female, square for male) and lines to connect couples and children.
• Trace the path between the two individuals whose relationship is being asked.
• Be mindful of terms like "only child," "only son," "only daughter," as they provide crucial constraints.
• Pay attention to phrases like "P is Q's brother" vs. "P is brother of Q".

Practicing different types of relationship structures will help you solve these questions more quickly and accurately.