Statements: All boys are tall. Rajiv is a boy. Conclusions: I. Rajiv is tall.…
2026
Statements:
All boys are tall.
Rajiv is a boy.
Conclusions:
I. Rajiv is tall.
II. Rajiv is not tall.
- A.
Only Conclusion I follows
- B.
Only Conclusion II follows
- C.
Both Conclusion I and Conclusion II follow
- D.
Neither Conclusion I nor Conclusion II follows
Attempted by 31 students.
Show answer & explanation
Correct answer: A
Concept: When a universal affirmative premise of the form ‘All A are B’ is combined with another premise asserting that an individual C belongs to A (‘C is A’), the direct-implication rule of categorical syllogism gives an A-type conclusion ‘C is B’ — since C is a member of A, and every member of A also belongs to B, C must belong to B.
Application:
Premise 1: All boys are tall — the set of boys lies entirely within the set of tall people.
Premise 2: Rajiv is a boy — Rajiv belongs to the set of boys.
Combining the universal affirmative premise with Rajiv's individual membership in the class 'boys' gives the direct affirmative conclusion: since every boy is tall and Rajiv is a boy, Rajiv must be tall.
This derived statement, ‘Rajiv is tall’, is exactly Conclusion I, so Conclusion I follows.
Cross-check: Conclusion II states the opposite (‘Rajiv is not tall’), which directly contradicts the fact just derived from the premises, so it cannot follow. Since the premises guarantee Conclusion I with certainty (not a mere possibility), the case of ‘either follows’ does not apply, and since one conclusion is already proven, ‘neither follows’ is also ruled out.
Result: Only Conclusion I follows.