Statements: All dancers are artists. No artist is lazy. Conclusions: I. No dancer is lazy. II. Some lazy are dancers.
- (a)Only I follows
- (b)Only II follows
- (c)Both I and II follow
- (d)Neither I nor II follows
Answer
Why
Correct — A.
Rule: All A are B + No B is C ⇒ No A is C.
Every dancer is inside the artists' circle, and the lazy circle does not touch the artists. So it cannot touch the dancers: No dancer is lazy, and conclusion I follows.
Conclusion II, some lazy are dancers, would put a lazy person among the dancers, which I rules out. II fails, so the answer is option (a), Only I follows.
Why the others are wrong
- (b)Only II follows — Conclusion II says some lazy people are dancers. The statements put every dancer among the artists and no artist among the lazy, so II is ruled out, not merely unproven.
- (c)Both I and II follow — Both cannot follow: I says no dancer is lazy and II says some lazy are dancers. The two contradict each other, and the statements back I.
- (d)Neither I nor II follows — Neither is wrong because conclusion I is forced by the statements. Every dancer is an artist and no artist is lazy, which leaves no room for a lazy dancer.
Concept
A two-statement syllogism links a first group to a third through a middle term. Here the middle term is artists: dancers lie wholly inside it, and the lazy lie wholly outside it.
That chain gives a certain universal negative: no dancer is lazy. Draw dancers inside artists and lazy as a separate circle, then test each conclusion against the drawing, not against what sounds plausible.
Conclusion II is not the converse of conclusion I. The converse of No dancer is lazy is No lazy person is a dancer, which follows. Some lazy are dancers is its direct contradiction.
Key facts
- All A are B and No B is C together give No A is C.
- No A is C converts to No C is A.
- Some C are A contradicts No A is C, so the two cannot both be true.
Study next
Common traps
- Reading II as the converse of I. The converse is No lazy person is a dancer, the opposite of II.
- Accepting both conclusions because each links the same two groups.
The same All-then-No chain is keyed at 26 Sep 2024, 09:00, Reasoning Q.7: All green are pink and No pink is blue give No green is blue, while Some blue are red fails.
19 Sep 2024, 09:00, Reasoning Q.19 reads the chain from the other end: All sparrows are parrots and No parrot is a penguin give No penguin is a sparrow.
Related PYQs
No directly related past PYQ was found.