O is the brother of R and S. T is S's mother. U is O's father. Which of the following statements cannot be definitely true?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → R is U’s husband
The clues are joined into one family:
O is the brother of R and S, so O, R and S are siblings (O is male; the genders of R and S are not given)
T is S’s mother, so T is the mother of all three siblings
U is O’s father, so U (male) is the father of all three, and U and T are husband and wife
“R is U’s husband” cannot be true: R is U’s child, and U, a father, is the husband of T.
The other three statements, U is R’s father, T is O’s mother and U is T’s husband, all follow from the family above.