The following question has three statements I, II and III. You have to decide whether the data given in the statements are sufficient to answer it.
Read the statements carefully and choose the correct option.
How many sons does X have?
Statements:
I. Q and U are brothers of T.
II. R is the sister of P and U.
III. R and T are daughters of X.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → I, II and III together are not sufficient
To count X's sons, each child of X must be found and known to be male. Take the statements together:
III: R and T are daughters of X.
I with III: Q and U are brothers of T, so they are children of X and male: Q and U are sons of X.
II: R is the sister of P and U, so P is also a child of X; but no statement gives P's gender.
X has two sons (Q and U) if P is a daughter, and three if P is a son. Even all three statements together cannot settle this, so the number of sons cannot be found.
Tip: A word such as “sister” or “brother” gives the gender of the person it describes (R), never of the person named after it (P).