A is the father of B. B is the brother of C. How is A related to C?
- (a)Uncle
- (b)Father
- (c)Brother
- (d)Grandfather
Answer
Why
Correct — B.
Rule: brothers and sisters share a father.
A is the father of B.
B is the brother of C, so B and C are siblings.
The father of one sibling is the father of the other, so A is C's father → option (b).
Why the others are wrong
- (a)Uncle — Uncle is a parent's brother. A is B's father, not the brother of B's father, so A is a parent of the siblings, not their uncle.
- (c)Brother — Brother would put A in C's generation. But A is the father of C's brother B, which places him one generation above C.
- (d)Grandfather — Grandfather is two generations up. A is B's father and B is in C's generation, so A is only one generation above C.
Concept
Blood-relation items turn on generations. A parent is one generation up; a brother or sister is the same generation.
A is the father of B, one generation above B. B is C's brother, so C is in B's generation. A is therefore one generation above C, on the direct line: C's father.
C's gender is never given, and it does not matter: A is the father whether C is a son or a daughter. The key also takes brother in its usual sense of a full sibling sharing both parents.
Key facts
- Siblings share their parents, so the father of B is the father of B's brother or sister.
- A is C's father whatever C's gender is.
- An uncle is a parent's brother, and a grandfather is a parent's father.
Study next
Common traps
- Choosing grandfather by counting two statements as two generations, though a brother is the same generation
- Stalling because C's gender is unknown, though father holds either way
18 Sep 2025, 12:30, Reasoning Q.22 uses the same rule: S is the father of P, P and R are siblings, so R is keyed as S's daughter (option a).
19 Sep 2025, 09:00, Reasoning Q.22 moves one step sideways: A is B's brother, B is C's sister, C is D's father, so A is D's uncle (option a).
Related PYQs
No directly related past PYQ was found.