How is Fred related to Arthur? Statements: I. George is the brother of Fred.…

Concept: In data-sufficiency questions on family or blood relations, a statement is sufficient by itself only when it directly and completely fixes the specific relationship the question asks for, using only the two people named in the question. A statement that talks about some other person, without also connecting that person to both of the named individuals, cannot answer the question on its own.

Application: Here the question asks how Fred is related to Arthur. The first statement links only George and Fred (a sibling relation) and never mentions Arthur at all, so it carries no information relevant to Arthur. The second statement gives, in a single line, the exact relationship the question is asking for: it names Arthur and Fred and states the family role that connects them directly.

Cross-check: Checking the two statements independently, rather than assuming they must be combined, is the standard first step in a sufficiency question: test statement I alone, then statement II alone, before considering any combination. That check shows one of the two lines already gives a complete, unambiguous, one-step relationship between Arthur and Fred, while the other line contributes nothing about Arthur under any combination.

• Statement I alone is sufficient — incorrect, since this statement never refers to Arthur at all; a sibling fact about George cannot establish any relationship to Arthur.

• Statement II alone is sufficient — correct, since this single statement already states the family role linking Arthur and Fred directly, with nothing else required.

• Both statements together are sufficient — incorrect as a description of what is needed, since statement I adds nothing about Arthur; the relationship is already fixed without it.

• Both statements together are not sufficient — incorrect, since statement II alone already gives a complete and direct relationship between Arthur and Fred.

So statement II alone is sufficient to answer how Fred is related to Arthur (Fred is Arthur's son), and answering the question does not require statement I at all.