There are four questions based on the same puzzle. Answer the questions based…
2025
There are four questions based on the same puzzle. Answer the questions based on the given information
A, S, O, D, F, T are members of a family consisting of 3 men and 3 women among whom there are two married couples. We also known that:
I. O is the son of S
II. T is the daughter of D
III. F is the grandson of A
IV. D is the mother of a girl and a boy
V. S is not the father of O
VI. All the relationship mentioned above are between these six persons only.
T's grandmother is?
- A.
D
- B.
F's mother
- C.
A
- D.
S
Show answer & explanation
Correct answer: D
Concept:
In a family-tree (blood relation) puzzle, first fix each person's gender and parent-child links from the direct clues, then use the parent of the correct side (paternal or maternal) two generations up to answer a grandparent question. A clue that rules out one gender for a stated parent (e.g. "X is not the father of Y") is the key that fixes sex when it is not given directly.
Application:
From clue I, O is the child of S.
From clue V, S is not the father of O, so S must be female and is O's mother.
From clue IV, D is the mother of one girl and one boy.
From clue II, T is the daughter of D, so T is the girl referred to in clue IV; the boy must be F, since O is already fixed as S's child and not D's.
So D is the mother of both F (son) and T (daughter), which makes D's husband their father.
Only two married couples exist among the six members. S's husband must be O's father; since O, D, F and T are already placed as children or mother in the tree above, the only person left to pair with S is A. So A and S are the parents of O.
The second couple pairs D with the remaining man, O -- O is D's husband and the father of F and T.
Clue III (F is the grandson of A) checks out: F's father is O, and O's father is A, so F is A's grandson through O.
T's parents are O and D. O's mother is S, so S is T's paternal grandmother.
Cross-check:
Every clue (I-VI) is satisfied by this tree: A and S are one couple (parents of O), O and D are the other couple (parents of F and T), all three women (S, D, T) and three men (A, O, F) are accounted for, and no relation outside these six is used. This confirms T's grandmother is S.