A syllogism has two or more statements followed by conclusions. You must check if the conclusions logically follow from the statements, ignoring what you know about the real world
💡Key Rules
(1) Accept all statements as true, even if they seem wrong in reality. (2) Use only the given information. (3) Draw conclusions based purely on logical connections. (4) 'Some' means 'at least one but not all'. (5) 'All' means '100% without exception'
🔑Venn Diagram Method
This is the most reliable approach. Draw circles to represent each category mentioned in statements. Overlap circles based on relationships given in statements. Check if conclusions match your diagram.
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Exam Patterns
What examiners ask — read before attempting PYQs
📋SSC CGL typically asks
(1) Statement-Conclusion type (2-3 statements, 2-4 conclusions to verify) (2) Only conclusion follows questions (3) Possibility-based conclusions. Most questions use words like All, Some, No, Few.
Shortcut Formula #1 - Conversion Rule: 'All A are B' can be converted to 'Some B are A'. But 'All A are B' cannot be converted to 'All B are A'.
Shortcut Formula #2 - Negative Conclusions: If both statements are positive, the conclusion cannot be negative. If one statement is negative, the conclusion must be negative
✏️Worked Example 1
Statements: (1) All roses are flowers (2) Some flowers are red
Conclusions: (I) Some roses are red (II) All red things are flowers
Solution: Draw three circles - Roses (inside Flowers circle), Flowers (big circle), Red (overlapping with Flowers). From the diagram, roses and red may or may not overlap. Conclusion I is 'possible but not definite' - so FALSE. Conclusion II says all red are flowers, but statement 2 only says some flowers are red, not the reverse - so FALSE
→Answer
Neither conclusion follows
✏️Worked Example 2
Statements: (1) No cats are dogs (2) All cats are animals
Conclusions: (I) No dogs are cats (II) Some animals are cats
Solution: Draw separate circles for cats and dogs (no overlap due to 'No'). Draw animals circle containing cats circle completely
→Conclusion I
'No dogs are cats' is the same as 'No cats are dogs' - TRUE
→Conclusion II
Since all cats are animals, definitely some animals are cats - TRUE
→Answer
Both conclusions follow.
Trick #3 - Possibility Conclusions: When a conclusion uses 'Some X can be Y' or 'X is a possibility', it's asking if the relationship is possible, not definite. Even if something is not proven definite, it might still be possible.
Common Mistake #1: Students use real-world knowledge instead of logical reasoning. For example, if given 'All books are tigers', students reject it as impossible. In syllogism, you must accept this as true for that question and proceed logically
⚡Time-Saving Approach
For statement-conclusion questions, quickly eliminate obviously wrong conclusions first. Look for direct contradictions with statements. Then use Venn diagrams only for remaining conclusions. This saves precious exam time.
Medium/Definite Rule: If conclusion says 'definitely' or uses strong words like 'certainly', it needs 100% proof from statements.
If it says 'can be' or 'possible', it needs only logical possibility, not certainty.
Statements:
1. No reptiles are mammals.
2. All snakes are reptiles.
Conclusion: No snakes are mammals.
Is the conclusion valid?
Practice 2easy
Statements:
1. All teachers are educated.
2. Some educated people are doctors.
Conclusion: Some teachers are doctors.
Is the conclusion valid?
Practice 3easy
Statements:
1. All teachers are educated.
2. Some educated people are not strict.
Conclusion: Some teachers are not strict.
Is the conclusion valid?
Practice 4easy
Statements:
1. All fruits are sweet.
2. No sour things are sweet.
Conclusion: No fruits are sour.
Is the conclusion valid?
Practice 5easy
Statements:
1. All fruits are healthy.
2. Some healthy things are expensive.
Conclusion: Either all fruits are expensive, or some fruits are not expensive.
Is the conclusion valid?
Practice 6easy
Statements:
1. Some politicians are honest.
2. All honest people are trustworthy.
Conclusion: Some politicians are trustworthy.
Is the conclusion valid?
Practice 7easy
Statements:
1. All mammals are animals.
2. All dogs are mammals.
Conclusion: All dogs are animals.
Is the conclusion valid?
Practice 8easy
Statements:
1. No criminals are honest.
2. All dishonest people are criminals.
Conclusion: All dishonest people are criminals.
Is the conclusion valid?
Practice 9easy
Statements:
1. All flowers are plants.
2. No plants are animals.
Conclusion: No flowers are animals.
Is the conclusion valid?
Practice 10medium
Statements:
1. All athletes are disciplined.
2. Some disciplined people are not successful.
Conclusion: Some athletes are not successful.
Is the conclusion valid?
Practice 11medium
Statements:
1. No corrupt officials are trustworthy.
2. All judges are trustworthy.
Conclusion: Either all judges are corrupt officials, or no judges are corrupt officials.
Which conclusion is valid?
Practice 12medium
Statements:
1. Some writers are poets.
2. All poets are creative.
Conclusion: All writers are creative.
Is the conclusion valid?
Practice 13medium
Statements:
1. No corrupt officials are trustworthy.
2. All judges are trustworthy.
3. Some lawyers are corrupt officials.
Conclusion: Which of the following must be true?
(A) All lawyers are judges.
(B) Some lawyers are not trustworthy.
(C) No lawyers are judges.
(D) Some lawyers are judges.
Practice 14medium
Statements:
1. All engineers are problem-solvers.
2. Some problem-solvers are not innovators.
Conclusion: Some engineers are not innovators.
Is the conclusion valid?
Practice 15hard
Statements: All pens are books. No book is a copy. Some copies are pencils.
Conclusions:
I. No pen is a copy.
II. Some pencils are not books.
III. Some pencils are pens.
Which of the following is correct?
Practice 16hard
Statements:
1. All philosophers are critical thinkers.
2. Some critical thinkers are not disciplined.
3. No disciplined person is lazy.
Which of the following conclusions is/are definitely true?
I. Some philosophers are not disciplined.
II. All lazy people are undisciplined.
III. Some critical thinkers are lazy.
Practice 17hard
Statements:
1. No corrupt official is trustworthy.
2. All judges are trustworthy.
3. Some government employees are corrupt officials.
Which of the following conclusions is/are definitely true?
I. Some government employees are not judges.
II. No judge is a corrupt official.
III. Some judges are government employees.
Practice 18hard
Statements:
1. All athletes are disciplined.
2. No lazy person is disciplined.
3. Some employees are lazy.
4. All athletes are employees.
Which of the following conclusions is/are definitely true?
I. Some employees are not athletes.
II. No athlete is lazy.
III. Some disciplined people are not employees.
Practice 19hard
Statements:
1. All engineers are problem-solvers.
2. All problem-solvers are analytical.
3. Some analytical people are not creative.
Which of the following conclusions must be true?
I. Some engineers are not creative.
II. All engineers are analytical.
III. Some problem-solvers are creative.
Practice 20hard
Statements:
1. All successful entrepreneurs are risk-takers.
2. Some risk-takers are not visionary.
3. All visionaries are strategic planners.
Consider the following conclusions:
I. Some entrepreneurs are not strategic planners.
II. Some strategic planners are not risk-takers.
III. Either all entrepreneurs are strategic planners, or some entrepreneurs are not strategic planners.
Which conclusion(s) must be true?
60-Second Revision — Syllogism
Remember: Accept all statements as true, ignore real-world knowledge
Formula: All A→B converts to Some B→A, not All B→A
Trap: Using real-world logic instead of pure logical reasoning
Method: Use Venn diagrams for visual clarity and accuracy
Rule: Positive statements cannot produce negative conclusions
Trick: Eliminate contradictory conclusions first to save time
Focus: 'Some' = at least one, 'All' = 100%, 'Possible' = logically feasible