Question 1

Statements:
1. Some politicians are corrupt.
2. All corrupt people are untrustworthy.

Conclusion: Some politicians are untrustworthy.

Which of the following is true?
A) The conclusion logically follows
B) The conclusion does not logically follow
C) The conclusion is true but not necessarily from these premises
D) The conclusion is definitely false

Accepted Answer

The conclusion logically follows. From Premise 1, some politicians are corrupt. From Premise 2, all corrupt people are untrustworthy. Therefore, those politicians who are corrupt must be untrustworthy, making the conclusion valid.

Question 2

Statements:
1. No criminals are honest.
2. All thieves are criminals.

Conclusion: No thieves are honest.

Which of the following is true?
A) The conclusion logically follows
B) The conclusion does not logically follow
C) The conclusion is true but not from these premises
D) The conclusion contradicts the premises

Accepted Answer

The conclusion logically follows. From premise 2, all thieves are criminals. From premise 1, no criminals are honest. Therefore, by transitive logic, no thieves can be honest.

Question 3

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

Conclusion: Some doctors are teachers.

Which of the following is true?
A) The conclusion logically follows
B) The conclusion does not logically follow
C) The conclusion is partially true
D) The conclusion is definitely false

Accepted Answer

The conclusion does not logically follow. From the premises, we know all teachers are educated and some educated people are doctors. However, this does not guarantee that any of those doctors are teachers. The educated doctors could be a completely separate group from teachers.

Question 4

Read the following statements carefully and answer the question.

Statements:
1. All teachers are educated.
2. Some educated people are not disciplined.
3. No disciplined person is lazy.

Which of the following conclusions is definitely true?

A) All teachers are disciplined.
B) Some teachers are lazy.
C) Either all teachers are disciplined or some teachers are not disciplined.
D) No teacher is lazy.

Accepted Answer

This syllogism tests the ability to derive valid conclusions from multiple premises using the 'All/Some/No' framework and recognize when an 'Either/Or' conclusion is the only logically sound option.

Step-by-step solution:
1. From Statement 1: All teachers are educated. (Teachers ⊆ Educated)
2. From Statement 2: Some educated people are not disciplined. (Some Educated ∉ Disciplined)
3. From Statement 3: No disciplined person is lazy. (Disciplined ∩ Lazy = ∅)

Analyzing each option:
- Option A (All teachers are disciplined): INVALID. Statement 2 tells us some educated people are not disciplined. Since teachers are educated, some teachers could be among those not disciplined. This is not necessarily true.
- Option B (Some teachers are lazy): INVALID. We cannot conclude this. Teachers are educated, but we don't know if any teacher falls into the 'not disciplined' category that might be lazy.
- Option C (Either all teachers are disciplined OR some teachers are not disciplined): VALID. This is a logical tautology in this context. Since we cannot definitively prove all teachers are disciplined (due to Statement 2), and we cannot prove no teachers are undisciplined, one of these two must be true. This exhausts all possibilities.
- Option D (No teacher is lazy): INVALID. While no disciplined person is lazy, we don't know if all teachers are disciplined, so we cannot conclude no teacher is lazy.

The correct answer is C because it presents the only conclusion that must logically hold given the premises.

Question 5

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

Conclusion: No birds are plants.

Which of the following is true?
A) The conclusion logically follows
B) The conclusion does not logically follow
C) The conclusion is true but requires external knowledge
D) The conclusion contradicts the first premise

Accepted Answer

The conclusion logically follows. All birds are animals (Premise 1), and no animals are plants (Premise 2). By the transitive property of categorical logic, if birds are animals and animals are not plants, then birds cannot be plants.

Question 6

Statements:
1. All athletes are disciplined.
2. No lazy person is disciplined.
3. Some employees are lazy.

Conclusions:
I. Some employees are not athletes.
II. All employees are either athletes or lazy.

Which of the following is true?

Accepted Answer

From the premises: athletes are disciplined, lazy people are not disciplined, and some employees are lazy. The lazy employees cannot be athletes. However, Conclusion II claims all employees are either athletes or lazy, which is not necessarily true—some employees could be neither lazy nor athletes.

Question 7

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

Conclusions:
I. Some engineers are not innovators.
II. All problem-solvers are engineers.

Which of the following is true?

Accepted Answer

This tests understanding of the logical limits of 'Some' and 'All' statements. From 'All engineers are problem-solvers' and 'Some problem-solvers are not innovators,' we cannot definitively conclude that some engineers are not innovators (the non-innovators could be from the problem-solvers who aren't engineers). Conclusion II reverses the direction of the 'All' statement, which is logically invalid.

Question 8

Statements:
1. No corrupt official is trustworthy.
2. All judges are trustworthy.
3. Some lawyers are corrupt officials.

Conclusions:
I. Some lawyers are not judges.
II. No lawyer is a judge.

Which conclusion(s) logically follow(s)?

Accepted Answer

From the premises: corrupt officials are excluded from trustworthy people (Premise 1), judges are all trustworthy (Premise 2), and some lawyers are corrupt (Premise 3). Therefore, those lawyers who are corrupt cannot be judges. This means at least some lawyers are not judges, but we cannot conclude that NO lawyer is a judge (some non-corrupt lawyers could be judges).

Question 9

Statements:
1. All successful entrepreneurs are risk-takers.
2. Some risk-takers are not financially stable.
3. No financially stable person is unsuccessful.

Conclusions:
I. Some successful entrepreneurs are not financially stable.
II. All unsuccessful people are not risk-takers.

Which conclusion(s) logically follow(s)?

Accepted Answer

From the premises: successful entrepreneurs take risks, some risk-takers lack financial stability, and unsuccessful people are not financially stable (contrapositive: financially stable people are successful). We cannot conclude that some successful entrepreneurs are not financially stable (the unstable risk-takers could be non-entrepreneurs). Conclusion II is invalid because unsuccessful people could be risk-takers; the premises only say unsuccessful people are not financially stable.

Question 10

Statements:
1. All senior managers are decision-makers.
2. Some decision-makers are not strategic planners.
3. All strategic planners are visionaries.
4. No visionaries are indecisive.

Which of the following must be true?

A) All senior managers are strategic planners.
B) Some senior managers are not strategic planners.
C) Either all senior managers are visionaries or no senior managers are visionaries.
D) Some decision-makers are visionaries.

Accepted Answer

Hard four-statement syllogism with mixed quantifiers and negation; tests transitive reasoning and the ability to avoid false generalizations.

Question 11

Read the following statements carefully and answer the question.

Statement 1: All philosophers are critical thinkers.
Statement 2: Some critical thinkers are not educators.
Statement 3: No educators are dogmatists.

Which of the following conclusions can be validly derived?

I. Some philosophers are not educators.
II. All dogmatists are either non-critical thinkers or non-educators.
III. Some critical thinkers are philosophers.

Accepted Answer

This is a hard syllogism question testing the ability to derive valid conclusions from three premises using set logic and the either/or construct. Students must track multiple overlapping categories and avoid drawing conclusions that exceed the logical scope of the premises.

Question 12

Statements:
1. No successful entrepreneurs are risk-averse.
2. All innovators are risk-takers.
3. Some risk-takers are not successful entrepreneurs.

Which conclusion is logically valid?

A) All innovators are successful entrepreneurs.
B) Some innovators are not successful entrepreneurs.
C) Either all innovators are successful entrepreneurs or no innovators are successful entrepreneurs.
D) No innovators are risk-averse.

Accepted Answer

Hard syllogism requiring negation handling and understanding of the relationship between three overlapping sets with explicit exclusions.

Question 13

Statements:
1. All certified accountants are detail-oriented professionals.
2. No detail-oriented professionals are careless.
3. Some employees are careless.
4. All certified accountants are employees.

Which of the following must be true?

A) Some employees are not certified accountants.
B) All employees are detail-oriented professionals.
C) Either some employees are certified accountants or no employees are certified accountants.
D) Some detail-oriented professionals are not employees.

Accepted Answer

Four-statement hard syllogism testing transitive chains, negation handling, and the ability to identify what MUST be true versus what COULD be true.

Question 14

Statements:
1. All renewable energy sources are sustainable.
2. Some sustainable technologies are not cost-effective.
3. No cost-effective solutions are renewable energy sources.

Which conclusion is definitely valid?

A) All renewable energy sources are cost-effective.
B) Some renewable energy sources are not cost-effective.
C) Either all renewable energy sources are cost-effective or some are not cost-effective.
D) All sustainable technologies are renewable energy sources.

Accepted Answer

Hard syllogism with circular negation and contrapositive reasoning; tests whether students can identify logical contradictions and derive forced conclusions.

Question 15

Statements:
1. All philosophers are rational thinkers.
2. Some rational thinkers are not poets.
3. No poets are illogical.

Which of the following conclusions is definitely true?

A) All philosophers are poets.
B) Some philosophers are not poets.
C) Either all philosophers are poets or no philosophers are poets.
D) Some rational thinkers are philosophers.

Accepted Answer

This question tests the ability to derive valid conclusions from three-statement syllogisms with mixed quantifiers and negations.

SBI PO Syllogism

Syllogism— Rules & Concept

Key Points to Remember

Exam-Specific Tips

Syllogism — Practice Questions

60-Second Revision — Syllogism