Question

There are six persons A, B, C, D, E and F. C is the sister of F. B is the brother of E's husband. D is the father of A and the grandfather of F. There are two fathers, three brothers and a mother in the group. How many male members are there in the group?

• A. One
• B. Two
• C. Three
• D. Four

Hint:

Translate each sentence into family roles and genders, sketch a small family tree, then verify the global counts (fathers, brothers, mother) before answering.

Answer 1

The Correct Option is D

Let us map relations and genders.
- “C is the sister of F” \(\Rightarrow\) \(C\) is female; \(F\) is a sibling (gender unknown yet).
- “B is the brother of E’s husband” \(\Rightarrow\) \(B\) is male; \(E\) is female; \(E\)’s husband is male.
- “D is the father of A and the grandfather of F” \(\Rightarrow\) \(D\) is male; \(F\) is a child of \(A\).
- We must have exactly two fathers, three brothers, and one mother in the group.
Take \(E\)’s husband as \(A\). Then \(B\) is the brother of \(A\).
Since \(D\) is father of \(A\) (and \(B\)), and grandfather of \(F\) through \(A\), let \(A\) and \(E\) be the parents of \(C\) and \(F\).
Choose \(F\) as male (brother of \(C\)) to satisfy “three brothers”. Then roles/genders become:
- \(D\): male, father.
- \(A\): male, father and brother (of \(B\)).
- \(B\): male, brother.
- \(F\): male, brother (of \(C\)).
- \(E\): female, the mother.
- \(C\): female, sister.
Counts: fathers \(=\{D,A\}\) (2), brothers \(=\{A,B,F\}\) (3), mother \(=\{E\}\) (1).
Hence the number of male members \(=\{D,A,B,F\}=4\).
\(\boxed{4}\)