All six members of a family A, B, C, D, E and F are travelling together. B is the son of C but C is not the mother of B. A and C are a married couple. E is the brother of C. D is the daughter of A. F is the brother of B. How many children does A have?

Introduction / Context:

This family-reasoning question asks you to reconstruct a small family tree from several clues about a married couple and their relatives and then determine how many children one specific person (A) has. These types of questions test your ability to combine information about marriage, parentage and sibling relationships without losing track of the structure.

Given Data / Assumptions:

• There are six family members: A, B, C, D, E and F.
• B is the son of C, but C is not the mother of B.
• A and C are a married couple.
• E is the brother of C.
• D is the daughter of A.
• F is the brother of B.
• We assume typical nuclear-family conventions: children have the married couple as parents unless otherwise indicated.

Concept / Approach:

The key is to identify who is male and who is female, who is married to whom, and who are the parents of each child. From "B is the son of C but C is not the mother of B", we can infer that C is B's father. Since A and C form the married couple, A must be the mother. Then, using the facts about D and F, we can determine how many children A has altogether.

Step-by-Step Solution:

Step 1: "A and C are a married couple." So A and C are husband and wife. Step 2: "B is the son of C but C is not the mother of B." If C is not the mother yet is a parent of B, then C must be the father of B, meaning C is male. Step 3: Since C is male (the father in the couple), A must be female (the mother in the couple) to form a standard husband–wife pair. Step 4: As B is the son of C, and A is C's wife, B is naturally the child of both C and A. Thus B is a child of A. Step 5: "D is the daughter of A." Because A and C are married, D is also a child of both A and C, and specifically a daughter. Step 6: "F is the brother of B." Since F is B's brother, F is another child of the same parents (A and C) under the usual assumption that siblings share parents. Therefore, F is also a child of A. Step 7: Summarizing, A's children are B (son), D (daughter) and F (son). That gives A a total of three children.

Verification / Alternative check:

Place everyone in a family tree: A (mother) and C (father) are the married couple. Their children are B (son), D (daughter) and F (son). E is the brother of C and does not affect the child count of A. All given statements remain true:

• B is the son of C, and C is not the mother, so he is the father.
• A and C are married.
• D is indeed the daughter of A.
• F, as another son of A and C, is the brother of B.

This confirms that the count of A's children is exactly three.

Why Other Options Are Wrong:

"1" or "2" would ignore at least one of the children B, D or F, contradicting the explicit statements.

"4" would require introducing another child of A that is not mentioned in the problem, which goes beyond the given information.

Common Pitfalls:

A common error is to think that because the problem says "B is the son of C" and "C is not the mother of B", B might only be connected to C and not to A. But since A and C are specifically described as a married couple and no other partner for C is introduced, the standard assumption in reasoning questions is that children mentioned are of that couple. Another trap is to treat F as some other relative (e.g., cousin), but the usual puzzle convention is that "brother" means sibling sharing the same parents unless otherwise specified.

Final Answer:

A has three children.