Syllogism - Intermediate Level: definite conclusions INTERMEDIATE

Comprehensive weakness targeting worksheet covering 20 intermediate-level syllogism problems. Worksheet 18 of 30 emphasizes definite conclusions. Master propositional logic, logical conclusions, syllogistic reasoning through detailed explanations. Difficulty: moderate complexity with mixed patterns. Tailored for mid-level preparation.

📝 Worksheet 18 of 30 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Intermediate level

What you'll learn in this worksheet:
Your progress through Syllogism
Worksheet 18 of 30 (60% complete)

Question 1

Code Key: @ = All, # = Some, $ = No, & = are X = books, Y = novels, Z = publications Coded Statements: @ X & Y # Y & Z Decoded Conclusions: I. Some books are publications. II. All publications being books is a possibility.
Decoding Process:

Step 1: Decode the statements
@ X & Y → All books are novels
# Y & Z → Some novels are publications

Step 2: Apply syllogism rules
All A are B (A) + Some B are C (I) = A + I = No definite conclusion

Step 3: Check conclusions
✗ Conclusion I: "Some books are publications" - NOT DEFINITE
✓ Conclusion II: "All publications being books is a possibility" - No negatives, possibility exists

Coding Pattern:
@ (All), # (Some), $ (No) represent quantifiers
& represents "are"
Letters represent categories

Answer: Only conclusion II follows

Question 2

Statements: Some devices are vehicles. All vehicles are electronics. No electronics is a instruments. All instruments are tools. Conclusions: I. Some devices are electronics. II. No vehicles is a instruments. III. Some tools are not electronics.
Complex Multi-Statement Analysis:

Statement Chain:
1. Some devices are vehicles → Partial overlap
2. All vehicles are electronics → vehicles inside electronics
3. No electronics is a instruments → electronics and instruments separate
4. All instruments are tools → instruments inside tools

Checking Each Conclusion:

Conclusion I: "Some devices are electronics"
Some A are B (I) + All B are C (A) = I + A = I - FOLLOWS

Conclusion II: "No vehicles is a instruments"
All B are C (A) + No C is D (E) = A + E = E - FOLLOWS

Conclusion III: "Some tools are not electronics"
All D are E (A) + No C is D (E, converted) = A + E = O* - FOLLOWS

Answer: All conclusions I, II and III follow

Question 3

Statements: Some devices are vehicles. All vehicles are utensils. No utensils is a instruments. All instruments are tools. Conclusions: I. Some devices are utensils. II. No vehicles is a instruments. III. Some tools are not utensils.
Complex Multi-Statement Analysis:

Statement Chain:
1. Some devices are vehicles → Partial overlap
2. All vehicles are utensils → vehicles inside utensils
3. No utensils is a instruments → utensils and instruments separate
4. All instruments are tools → instruments inside tools

Checking Each Conclusion:

Conclusion I: "Some devices are utensils"
Some A are B (I) + All B are C (A) = I + A = I - FOLLOWS

Conclusion II: "No vehicles is a instruments"
All B are C (A) + No C is D (E) = A + E = E - FOLLOWS

Conclusion III: "Some tools are not utensils"
All D are E (A) + No C is D (E, converted) = A + E = O* - FOLLOWS

Answer: All conclusions I, II and III follow

Question 4

Code Key: @ = All, # = Some, $ = No, & = are M = roses, N = flowers, O = plants Coded Statements: @ M & N # N & O Decoded Conclusions: I. Some roses are plants. II. All plants being roses is a possibility.
Decoding Process:

Step 1: Decode the statements
@ M & N → All roses are flowers
# N & O → Some flowers are plants

Step 2: Apply syllogism rules
All A are B (A) + Some B are C (I) = A + I = No definite conclusion

Step 3: Check conclusions
✗ Conclusion I: "Some roses are plants" - NOT DEFINITE
✓ Conclusion II: "All plants being roses is a possibility" - No negatives, possibility exists

Coding Pattern:
@ (All), # (Some), $ (No) represent quantifiers
& represents "are"
Letters represent categories

Answer: Only conclusion II follows

Question 5

Statements: All pilots are scientists. No scientists is a writers. Conclusions: I. Some writers are pilots. II. No writers is a pilots.
Complementary Pair Concept:
Conclusions I and II form a complementary pair: "Some writers are pilots" and "No writers is a pilots"
These are opposite statements - at least one MUST be true.

Venn Diagram Method:
Step 1: "All pilots are scientists" → Circle of pilots inside scientists
Step 2: "No scientists is a writers" → Circles of scientists and writers completely separate
Step 3: Since pilots is inside scientists, and scientists is separate from writers, then pilots is also separate from writers
Step 4: Result: "No writers is a pilots" is TRUE

Analytical Method:
All pilots are scientists (A) + No scientists is a writers (E) = A + E = E = No pilots is a writers
By conversion: No writers is a pilots

Either-Or Case:
Since the conclusions form a complementary pair and one is definitely true, answer is "Either-Or".

Answer: Either conclusion I or II follows

Question 6

Statements: Some theories are ideas. All ideas are frameworks. Conclusions: I. All theories are frameworks. II. Some theories are not frameworks.
Complementary Pair Analysis:
Conclusions I and II form a complementary pair:
- "All theories are frameworks" (A-type)
- "Some theories are not frameworks" (O-type)
These are opposite statements where at least one can be true.

Venn Diagram:
Step 1: "Some theories are ideas" → Partial overlap
Step 2: "All ideas are frameworks" → ideas inside frameworks
Step 3: The part of theories overlapping with ideas is definitely inside frameworks
Step 4: But we DON'T know about the rest of theories

Possible Cases:
Case 1: All of theories inside frameworks → Conclusion I true
Case 2: Some of theories outside frameworks → Conclusion II true

Either-Or Rule:
When conclusions form complementary pair "All" and "Some not", answer is "Either-Or".

Answer: Either conclusion I or II follows

Question 7

Statements: Some amphibians are herbivores. All herbivores are wild. No wild is a omnivores. All omnivores are fish. Conclusions: I. Some amphibians are wild. II. No herbivores is a omnivores. III. Some fish are not wild.
Complex Multi-Statement Analysis:

Statement Chain:
1. Some amphibians are herbivores → Partial overlap
2. All herbivores are wild → herbivores inside wild
3. No wild is a omnivores → wild and omnivores separate
4. All omnivores are fish → omnivores inside fish

Checking Each Conclusion:

Conclusion I: "Some amphibians are wild"
Some A are B (I) + All B are C (A) = I + A = I - FOLLOWS

Conclusion II: "No herbivores is a omnivores"
All B are C (A) + No C is D (E) = A + E = E - FOLLOWS

Conclusion III: "Some fish are not wild"
All D are E (A) + No C is D (E, converted) = A + E = O* - FOLLOWS

Answer: All conclusions I, II and III follow

Question 8

Identify the logical fallacy in the following argument: All squares are rectangles. All rectangles are quadrilaterals. Therefore, all quadrilaterals are squares. What is the primary error in this reasoning?
Fallacy Detection Analysis:

Given Argument:
All squares are rectangles.
All rectangles are quadrilaterals.
Therefore, all quadrilaterals are squares.

Type of Fallacy: Invalid Conversion

Explanation:
Correct conclusion: All squares are quadrilaterals.

Common Syllogism Fallacies:
1. Undistributed Middle: Middle term not distributed in any premise
2. Illicit Major/Minor: Term distributed in conclusion but not in premise
3. Exclusive Premises: Two negative premises give no conclusion
4. Negative Conclusion from Positive Premises: Invalid

Correct Answer: Illicit conversion of A-type statement

Question 9

Identify the logical fallacy in the following argument: Some students are athletes. Some athletes are rich. Therefore, some students are rich. What is the primary error in this reasoning?
Fallacy Detection Analysis:

Given Argument:
Some students are athletes.
Some athletes are rich.
Therefore, some students are rich.

Type of Fallacy: Undistributed Middle

Explanation:
Middle term 'athletes' not distributed in either premise.

Common Syllogism Fallacies:
1. Undistributed Middle: Middle term not distributed in any premise
2. Illicit Major/Minor: Term distributed in conclusion but not in premise
3. Exclusive Premises: Two negative premises give no conclusion
4. Negative Conclusion from Positive Premises: Invalid

Correct Answer: Undistributed middle term fallacy (I + I gives no conclusion)

Question 10

Statements: Only vertebrates are warm-blooded. All warm-blooded are birds. Conclusions: I. All vertebrates are birds. II. Some birds are vertebrates.
Understanding 'Only' Statement:
"Only vertebrates are warm-blooded" means "All warm-blooded are vertebrates" (reversal!)

Conversion:
Original: Only vertebrates are warm-blooded
Converted: All warm-blooded are vertebrates

Venn Diagram:
Step 1: "All warm-blooded are vertebrates" → warm-blooded inside vertebrates
Step 2: "All warm-blooded are birds" → warm-blooded inside birds
Step 3: warm-blooded inside both vertebrates and birds

Checking Conclusions:

Conclusion I: "All vertebrates are birds"
We only know warm-blooded is inside both - vertebrates could be larger - DOES NOT FOLLOW

Conclusion II: "Some birds are vertebrates"
All warm-blooded are vertebrates and all warm-blooded are birds
The warm-blooded portion is common to both - FOLLOWS

Answer: Only conclusion II follows

Question 11

Multi-Dimensional Statements: Dimension 1: All expensive smartphones are branded. Dimension 2: Some branded smartphones are high-quality. Dimension 3: All high-quality smartphones are durable. Dimension 4: No durable smartphones is cheap. Conclusions: I. Some expensive smartphones are durable. II. Some high-quality smartphones are not cheap. III. All expensive smartphones being high-quality is a possibility.
Multi-Dimensional Syllogism Analysis:
Tracking multiple attributes/dimensions simultaneously.

Building Logical Chains:
Chain 1: expensive → branded (all), but branded → high-quality (only some)
Chain 2: high-quality → durable (all), durable → not cheap (all)

Checking Conclusions:
✗ Conclusion I: "Some expensive smartphones are durable" - Cannot determine - DOES NOT FOLLOW
✓ Conclusion II: "Some high-quality smartphones are not cheap" - All high-quality are not cheap - FOLLOWS
✓ Conclusion III: "All expensive smartphones being high-quality is a possibility" - No negatives prevent this - FOLLOWS

Answer: Conclusions II and III follow

Question 12

Statements: No vertebrates is a diurnal. All diurnal are warm-blooded. Conclusions: I. No vertebrates is a warm-blooded. II. Some warm-blooded are not vertebrates.
Venn Diagram Method:
Step 1: "No vertebrates is a diurnal" → Circles of vertebrates and diurnal don't overlap
Step 2: "All diurnal are warm-blooded" → Circle of diurnal completely inside warm-blooded
Step 3: vertebrates is separate from diurnal, but warm-blooded may overlap with vertebrates

Analytical Method (E + A = O*):
No vertebrates is a diurnal (E) + All diurnal are warm-blooded (A) = Some warm-blooded are not vertebrates (O*)

Verification:
✗ Conclusion I: "No vertebrates is a warm-blooded" - DOES NOT FOLLOW (warm-blooded circle is larger and can overlap with vertebrates)
✓ Conclusion II: "Some warm-blooded are not vertebrates" - FOLLOWS (the part of warm-blooded containing diurnal doesn't contain vertebrates)

Answer: Only conclusion II follows

Question 13

Temporal Statements: All students who study daily study for at least 5 hours every day. All students who score well are students who study daily. Some students who score well are students who get scholarships. Conclusions: I. Some students who get scholarships study for at least 5 hours every day. II. Some people who study for at least 5 hours every day are students who get scholarships. III. All students who get scholarships are definitely students who score well.
Temporal Syllogism Analysis:
Temporal syllogisms involve time-based conditions integrated with logical statements.

Logical Chain:
All students who score well are students who study daily + All students who study daily study for at least 5 hours every day = All students who score well study for at least 5 hours every day
Some students who score well are students who get scholarships + All students who score well study for at least 5 hours every day = Some students who get scholarships study for at least 5 hours every day

Checking Conclusions:
✓ Conclusion I: "Some students who get scholarships study for at least 5 hours every day" - FOLLOWS
✓ Conclusion II: "Some people who study for at least 5 hours every day are students who get scholarships" - Conversion of I - FOLLOWS
✗ Conclusion III: "All students who get scholarships are definitely students who score well" - Only "some" given, not "all" - DOES NOT FOLLOW

Answer: Only conclusions I and II follow

Question 14

Statements: No diurnal is a vertebrates. All fish are vertebrates. Conclusions: I. No vertebrates is a diurnal. II. No fish is a diurnal. III. Some vertebrates are not diurnal.
Immediate vs Mediate Inference:

Immediate Inference: Direct conversion from one statement
Mediate Inference: Deduction requiring multiple statements

Checking Each Conclusion:

Conclusion I: "No vertebrates is a diurnal" - IMMEDIATE INFERENCE
Conversion of "No diurnal is a vertebrates" - FOLLOWS

Conclusion II: "No fish is a diurnal" - MEDIATE INFERENCE
All C are B (A) + No B is A (E) = A + E = E - FOLLOWS

Conclusion III: "Some vertebrates are not diurnal" - IMMEDIATE INFERENCE
From "No A is B", definitely some B are not A - FOLLOWS

Answer: All conclusions I, II and III follow

Question 15

Statements: All domestic are cold-blooded. Some domestic are carnivores. Conclusions: I. Some cold-blooded are carnivores. II. All cold-blooded being carnivores is a possibility. III. Some carnivores are cold-blooded.
Distribution of Terms:
A term is DISTRIBUTED when statement makes claim about ALL members.
A term is UNDISTRIBUTED when statement refers to SOME members.

Statement Analysis:
Statement 1: "All domestic are cold-blooded" → domestic DISTRIBUTED, cold-blooded UNDISTRIBUTED
Statement 2: "Some domestic are carnivores" → Both UNDISTRIBUTED

Logical Deduction:
Some B are C (I) + All B are A (A) = I + A = I
Result: Some C are A OR Some A are C

Checking Conclusions:
✓ Conclusion I: "Some cold-blooded are carnivores" - FOLLOWS
✓ Conclusion II: "All cold-blooded being carnivores is a possibility" - No negatives exist - FOLLOWS
✓ Conclusion III: "Some carnivores are cold-blooded" - Conversion of I - FOLLOWS

Answer: All conclusions I, II and III follow

Question 16

Multi-Dimensional Statements: Dimension 1: All expensive smartphones are branded. Dimension 2: Some branded smartphones are high-quality. Dimension 3: All high-quality smartphones are durable. Dimension 4: No durable smartphones is cheap. Conclusions: I. Some expensive smartphones are durable. II. Some high-quality smartphones are not cheap. III. All expensive smartphones being high-quality is a possibility.
Multi-Dimensional Syllogism Analysis:
Tracking multiple attributes/dimensions simultaneously.

Building Logical Chains:
Chain 1: expensive → branded (all), but branded → high-quality (only some)
Chain 2: high-quality → durable (all), durable → not cheap (all)

Checking Conclusions:
✗ Conclusion I: "Some expensive smartphones are durable" - Cannot determine - DOES NOT FOLLOW
✓ Conclusion II: "Some high-quality smartphones are not cheap" - All high-quality are not cheap - FOLLOWS
✓ Conclusion III: "All expensive smartphones being high-quality is a possibility" - No negatives prevent this - FOLLOWS

Answer: Conclusions II and III follow

Question 17

Multi-Dimensional Statements: Dimension 1: All electric cars are eco-friendly. Dimension 2: Some eco-friendly cars are modern. Dimension 3: All modern cars are safe. Dimension 4: No safe cars is cheap. Conclusions: I. Some electric cars are safe. II. Some modern cars are not cheap. III. All electric cars being modern is a possibility.
Multi-Dimensional Syllogism Analysis:
Tracking multiple attributes/dimensions simultaneously.

Building Logical Chains:
Chain 1: electric → eco-friendly (all), but eco-friendly → modern (only some)
Chain 2: modern → safe (all), safe → not cheap (all)

Checking Conclusions:
✗ Conclusion I: "Some electric cars are safe" - Cannot determine - DOES NOT FOLLOW
✓ Conclusion II: "Some modern cars are not cheap" - All modern are not cheap - FOLLOWS
✓ Conclusion III: "All electric cars being modern is a possibility" - No negatives prevent this - FOLLOWS

Answer: Conclusions II and III follow

Question 18

Statements: No ornaments is a equipment. All machines are equipment. Conclusions: I. No equipment is a ornaments. II. No machines is a ornaments. III. Some equipment are not ornaments.
Immediate vs Mediate Inference:

Immediate Inference: Direct conversion from one statement
Mediate Inference: Deduction requiring multiple statements

Checking Each Conclusion:

Conclusion I: "No equipment is a ornaments" - IMMEDIATE INFERENCE
Conversion of "No ornaments is a equipment" - FOLLOWS

Conclusion II: "No machines is a ornaments" - MEDIATE INFERENCE
All C are B (A) + No B is A (E) = A + E = E - FOLLOWS

Conclusion III: "Some equipment are not ornaments" - IMMEDIATE INFERENCE
From "No A is B", definitely some B are not A - FOLLOWS

Answer: All conclusions I, II and III follow

Question 19

Statements: All vertebrates are domestic. No domestic is a nocturnal. Conclusions: I. Some nocturnal are vertebrates. II. No nocturnal is a vertebrates.
Complementary Pair Concept:
Conclusions I and II form a complementary pair: "Some nocturnal are vertebrates" and "No nocturnal is a vertebrates"
These are opposite statements - at least one MUST be true.

Venn Diagram Method:
Step 1: "All vertebrates are domestic" → Circle of vertebrates inside domestic
Step 2: "No domestic is a nocturnal" → Circles of domestic and nocturnal completely separate
Step 3: Since vertebrates is inside domestic, and domestic is separate from nocturnal, then vertebrates is also separate from nocturnal
Step 4: Result: "No nocturnal is a vertebrates" is TRUE

Analytical Method:
All vertebrates are domestic (A) + No domestic is a nocturnal (E) = A + E = E = No vertebrates is a nocturnal
By conversion: No nocturnal is a vertebrates

Either-Or Case:
Since the conclusions form a complementary pair and one is definitely true, answer is "Either-Or".

Answer: Either conclusion I or II follows

Question 20

Statements: No gadgets is a electronics. All electronics are tools. Conclusions: I. No gadgets is a tools. II. Some tools are not gadgets.
Venn Diagram Method:
Step 1: "No gadgets is a electronics" → Circles of gadgets and electronics don't overlap
Step 2: "All electronics are tools" → Circle of electronics completely inside tools
Step 3: gadgets is separate from electronics, but tools may overlap with gadgets

Analytical Method (E + A = O*):
No gadgets is a electronics (E) + All electronics are tools (A) = Some tools are not gadgets (O*)

Verification:
✗ Conclusion I: "No gadgets is a tools" - DOES NOT FOLLOW (tools circle is larger and can overlap with gadgets)
✓ Conclusion II: "Some tools are not gadgets" - FOLLOWS (the part of tools containing electronics doesn't contain gadgets)

Answer: Only conclusion II follows
Previous Worksheet Next Worksheet