Question 1

Statements:
1. No reptiles are mammals.
2. All snakes are reptiles.

Conclusion: No snakes are mammals.

Is the conclusion valid?

Accepted Answer

This is a straightforward categorical syllogism using the 'No' and 'All' quantifiers. From Statement 2, all snakes belong to the reptile category. From Statement 1, no reptile belongs to the mammal category. Therefore, by transitive exclusion, no snake can be a mammal. The logical chain is unbroken.

Question 2

Statements:
1. All teachers are educated.
2. Some educated people are doctors.

Conclusion: Some teachers are doctors.

Is the conclusion valid?

Accepted Answer

The conclusion is NOT valid. From 'All teachers are educated' and 'Some educated people are doctors', we cannot conclude that some teachers are doctors. The educated doctors may be a completely different subset of educated people from the teachers. There is no guaranteed overlap.

Question 3

Statements:
1. All teachers are educated.
2. Some educated people are not strict.

Conclusion: Some teachers are not strict.

Is the conclusion valid?

Accepted Answer

This is a classic syllogism testing whether a valid middle term connection exists. Statement 1 tells us all teachers fall within the educated group. Statement 2 tells us some educated people lack strictness. However, we cannot conclude that the non-strict educated people include any teachers—the non-strict group may be entirely outside the teacher subset. The conclusion commits a logical fallacy by assuming overlap without proof.

Question 4

Statements:
1. All fruits are sweet.
2. No sour things are sweet.

Conclusion: No fruits are sour.

Is the conclusion valid?

Accepted Answer

The conclusion is VALID. From 'All fruits are sweet' and 'No sour things are sweet', we can deduce that no fruit can be sour (because sour things are not sweet, and all fruits are sweet). This is a valid syllogism.

Question 5

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?

Accepted Answer

This question tests understanding of 'Either/Or' conclusions in syllogisms. From the premises, we know all fruits are healthy, and some healthy things are expensive. We cannot determine whether the expensive healthy things include any fruits or not. Therefore, we cannot conclude 'all fruits are expensive.' However, we also cannot prove that some fruits ARE expensive. The only certainty is that at least one of the two options (all expensive OR some not expensive) must be true—this is a tautology and thus valid.

Question 6

Statements:
1. Some politicians are honest.
2. All honest people are trustworthy.

Conclusion: Some politicians are trustworthy.

Is the conclusion valid?

Accepted Answer

This syllogism uses 'Some' and 'All' premises. Statement 1 establishes that at least one politician is honest. Statement 2 establishes that all honest people are trustworthy. Therefore, the honest politician(s) identified in Statement 1 must also be trustworthy. The conclusion logically follows with certainty.

Question 7

Statements:
1. All mammals are animals.
2. All dogs are mammals.

Conclusion: All dogs are animals.

Is the conclusion valid?

Accepted Answer

The conclusion is VALID. This is a classic transitive syllogism: if all dogs are mammals, and all mammals are animals, then all dogs are animals. The chain of 'All' statements creates a valid logical chain.

Question 8

Statements:
1. No criminals are honest.
2. All dishonest people are criminals.

Conclusion: All dishonest people are criminals.

Is the conclusion valid?

Accepted Answer

The conclusion is VALID. Statement 2 directly states 'All dishonest people are criminals.' The conclusion is simply a restatement of Premise 2, so it is logically valid.

Question 9

Statements:
1. All flowers are plants.
2. No plants are animals.

Conclusion: No flowers are animals.

Is the conclusion valid?

Accepted Answer

This is a standard categorical syllogism combining 'All' and 'No' premises. Statement 1 places all flowers within the plant category. Statement 2 states that plants and animals have no overlap. By logical necessity, flowers (being plants) cannot be animals. The conclusion is a direct consequence of the premises.

Question 10

Statements:
1. All athletes are disciplined.
2. Some disciplined people are not successful.

Conclusion: Some athletes are not successful.

Is the conclusion valid?

Accepted Answer

This syllogism tests whether students correctly apply the rule of the undistributed middle and recognize when a conclusion cannot be drawn from the given premises.

Question 11

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?

Accepted Answer

This question tests the ability to recognize when an 'Either/Or' conclusion is logically sound. Given the two premises, one of the two options in the Either/Or must be true.

Question 12

Statements:
1. Some writers are poets.
2. All poets are creative.

Conclusion: All writers are creative.

Is the conclusion valid?

Accepted Answer

This syllogism tests whether students can recognize the difference between 'Some' and 'All' and understand that a conclusion cannot be broader than its premises.

Question 13

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.

Accepted Answer

From Statement 1: No corrupt officials are trustworthy (Corrupt → ¬Trustworthy). From Statement 2: All judges are trustworthy (Judge → Trustworthy). From Statement 3: Some lawyers are corrupt officials. Since some lawyers are corrupt officials, and corrupt officials are not trustworthy, those lawyers who are corrupt officials are not trustworthy. Therefore, some lawyers are not trustworthy. This directly follows from the chain: Some lawyers are corrupt officials → those lawyers are not trustworthy.

Question 14

Statements:
1. All engineers are problem-solvers.
2. Some problem-solvers are not innovators.

Conclusion: Some engineers are not innovators.

Is the conclusion valid?

Accepted Answer

This is a classic syllogism testing the validity of drawing conclusions from 'All' and 'Some' premises. The conclusion attempts to combine information from both statements, but the logical chain is broken because 'Some problem-solvers are not innovators' does not guarantee that those non-innovators include any engineers.

Question 15

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?

Accepted Answer

Step 1: All pens are books → pens are a subset of books. Step 2: No book is a copy → since all pens are books, no pen is a copy. So Conclusion I ('No pen is a copy') FOLLOWS. Step 3: No book is a copy, and some copies are pencils. Those pencils that are copies cannot be books (since no book is a copy). So 'Some pencils are not books' FOLLOWS (Conclusion II). Step 4: No pen is a copy (proved above). Some copies are pencils. Since pens and copies share no members, and the pencils mentioned are copies, those pencils cannot be pens. So Conclusion III ('Some pencils are pens') does NOT follow. Therefore only Conclusions I and II follow.

Question 16

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.

Accepted Answer

This question tests the ability to distinguish between what is definitely true, possibly true, and definitely false in a three-premise syllogism with mixed quantifiers.

Question 17

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.

Accepted Answer

This question tests the ability to derive conclusions from a mix of universal negative, universal affirmative, and particular affirmative premises, and to distinguish between what is definitely true and what is merely possible.

Question 18

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.

Accepted Answer

This four-premise syllogism tests the ability to chain multiple universal statements and derive conclusions while avoiding false inferences from particular premises.

Question 19

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.

Accepted Answer

This question tests the ability to chain universal premises correctly and recognize what cannot be concluded from a mixed universal-particular premise structure.

Question 20

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?

Accepted Answer

This hard-difficulty question tests the ability to handle an 'Either/Or' (disjunctive) conclusion and recognize when a disjunction is necessarily true even if neither disjunct is individually certain.

SSC CHSL Syllogism

Syllogism— Rules & Concept

Key Points to Remember

Exam-Specific Tips

Syllogism — Practice Questions

60-Second Revision — Syllogism