Statements : I. Some birds are elephants. II. Some elephants are white. Inferences : A. Some birds are white. B. Some whites are birds. Codes

Picture the premises as two circles that overlap only in unknown places. Statement I places some birds inside the elephant circle. Statement II places some elephants inside the white circle. Those two groups of elephants need not be the same animals, so nothing links birds to white things.

• Inference A (Some birds are white) does not follow. The birds that are elephants could be entirely different from the white elephants, so no bird is forced to be white.
• Inference B (Some whites are birds) does not follow. Some whites are elephants, but the premises never tie any elephant to a bird in the same group.

So the correct answer is D. The concept is the existential 'some' in categorical syllogisms: two particular premises with a middle term that is not distributed give no valid conclusion. Venn diagrams settle this quickly, and the same discipline helps in Mains answers where you must not read more into a statement than it says.

Trap: Students see 'some birds are elephants' and 'some elephants are white' and join them into a chain. The two 'some' groups of elephants need not overlap, so the chain breaks.