ExamShortcut
high importance~3-5 Q in Tier 13 formulas⚑ 4 shortcuts4 subtopics

Syllogism questions hand you 2-3 statements (All / No / Some / Some-not / Only-a-few) as true and ask which conclusions follow. The reliable method is minimal-diagram plus counter-example hunting: draw the least-committal picture, then try to break each conclusion β€” a conclusion follows only if no valid diagram breaks it. Modern twists (possibility conclusions, either-or complementary pairs, 'only a few') all reduce to the same discipline with one twist: possibility needs just one supporting diagram, and either-or needs the two conclusions to be exact negations.

Track record in the exam

avg 1.5 Q / shift2024: 1–2 Q2025: 1–2 Q

Questions per shift in recent SSC CGL papers.

Test difficulty mix (50 questions)

10 easy23 medium17 hard

Question patterns exams keep repeating

Taken from previous-year papers. If a pattern is marked "very common", expect to see it in your exam.

Two-statement definite

very common
Spot it:

Two statements (an All and a Some/No in some order) with two conclusions about the outer terms.

How to solve: Draw the least-committal diagram, then hunt one counter-diagram per conclusion. The Some-member travels through an All; a No statement exiles it. Reject every conclusion a single moved diagram can break.

Example: Some dogs are cats. All cats are rats. Conclusions: I. Some dogs are rats. II. All rats are dogs.

The dog-cat member is a rat β†’ I follows. Rats spread beyond dogs β†’ II fails. Only I.

Learn this in β€œWhat a syllogism is and how to test it” β†’

Three-statement chain

common
Spot it:

Three statements, usually two All's and one Some/No, with conclusions that need the whole chain.

How to solve: Chain the All-links first (AβŠ‚BβŠ‚C), place the Some/No member last, and trace the guaranteed member through every statement it meets before judging any conclusion.

Example: All keys are locks. Some locks are doors. No door is a window. Conclusions: I. Some keys are doors. II. Some locks are not windows.

The lock-door overlap can dodge keys β†’ I fails. That door-lock is never a window β†’ II follows. Only II.

Learn this in β€œWhat a syllogism is and how to test it” β†’

Possibility conclusion

very common
Spot it:

Any conclusion ending in 'is a possibility'.

How to solve: Build ONE diagram where the possibility holds alongside every statement. It fails only when a guaranteed member would be forced into a forbidden (No) class. Definite and possibility use opposite standards β€” never mix them.

Example: All roads are streets. Some streets are lanes. Conclusion: All lanes being roads is a possibility.

Draw lanes inside roads, roads inside streets, extra streets outside β†’ consistent β†’ follows.

Learn this in β€œPossibility conclusions” β†’

Either-or complementary pair

very common
Spot it:

Neither conclusion follows alone but the pair is (All, Some-not) or (Some, No) about the same two terms.

How to solve: Check the shape first, then test each conclusion alone β€” if either follows by itself, pick it. Only a true negation pair with no individual proof earns 'Either I or II follows'.

Example: Some flowers are red. No flower is blue. Conclusions: I. All flowers are red. II. Some flowers are not red.

Neither is provable and the pair is exact negation β†’ Either I or II follows.

Learn this in β€œEither-or (complementary pairs)” β†’

Only-a-few statements

common
Spot it:

'Only a few A are B' β€” the modern quantifier.

How to solve: Rewrite as Some A are B + Some A are not B. The A-side split is guaranteed; the B-side is free. Chain only the overlap member through All statements; never chain the outside member.

Example: Only a few cups are plates. All plates are bowls. Conclusions: I. Some cups are not plates. II. No cup is a bowl.

I is guaranteed β†’ follows. Plate-cups are bowls and non-plate cups may be bowls β†’ II fails. Only I.

Learn this in β€œOnly-a-few and definite-case rulings” β†’

Conversion-based conclusion

occasional
Spot it:

The correct conclusion is a reversal: Some B are A from All A are B, or swapped Some/No.

How to solve: Recall the free conversions β€” Allβ†’Some, Some↔Some, No↔No β€” before rejecting a conclusion as 'reversed'. The only illegal reversal is All B are A.

Example: All roses are flowers. Conclusion: Some flowers are roses.

All→Some conversion always holds (no class is empty) → follows.

Learn this in β€œWhat a syllogism is and how to test it” β†’

Counter-example hunt

common
Spot it:

A conclusion that looks natural but rests on drawing the picture you want.

How to solve: Ask of every conclusion: can I move a free part of the diagram β€” push an overlap aside, extend a circle β€” while all statements stay true? One success rejects it. Follows only when no movement can break it.

Example: Some spoons are forks. Conclusion: Some spoons are not forks.

Draw all spoons inside the overlap β€” statements hold, conclusion breaks β†’ does not follow.

Learn this in β€œWhat a syllogism is and how to test it” β†’

Possibility blocked by a No statement

common
Spot it:

A possibility question whose statements include 'No X is Y' near the possibility's terms.

How to solve: Trace the member guaranteed by a Some or only-a-few statement. If drawing the possibility would push that member into the forbidden class, the possibility is impossible; otherwise it follows.

Example: Some phones are cameras. No camera is a charger. Conclusion: All phones being chargers is a possibility.

The phone-camera member can never be a charger β†’ does not follow.

Learn this in β€œPossibility conclusions” β†’

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