Syllogism - Intermediate-Advanced Level: complementary pairs INTERMEDIATE-ADVANCED

Strategic expert challenge ★ for syllogism: 20 intermediate-advanced-level problems. Worksheet 19 of 30 - Focus: complementary pairs. Develop expertise in logical conclusions, syllogistic reasoning, deductive arguments with step-by-step solutions. Ideal for advanced developing learners targeting advanced concepts with increasing complexity.

📝 Worksheet 19 of 30 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Intermediate-advanced level

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Worksheet 19 of 30 (63% complete)

Question 1

Statements: All writers are managers. Some writers are athletes. Conclusions: I. Some managers are athletes. II. All managers being athletes is a possibility. III. Some athletes are managers.
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 writers are managers" → writers DISTRIBUTED, managers UNDISTRIBUTED
Statement 2: "Some writers are athletes" → 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 managers are athletes" - FOLLOWS
✓ Conclusion II: "All managers being athletes is a possibility" - No negatives exist - FOLLOWS
✓ Conclusion III: "Some athletes are managers" - Conversion of I - FOLLOWS

Answer: All conclusions I, II and III follow

Question 2

Statements: All nocturnal are omnivores. All omnivores are diurnal. Conclusions: I. All nocturnal are diurnal. II. Some diurnal are nocturnal.
Venn Diagram Method:
Draw three circles for nocturnal, omnivores, and diurnal.

Step 1: "All nocturnal are omnivores" → Circle of nocturnal completely inside omnivores
Step 2: "All omnivores are diurnal" → Circle of omnivores completely inside diurnal
Step 3: Result: nocturnal ⊂ omnivores ⊂ diurnal

Analytical Method (A + A = A):
All nocturnal are omnivores (A) + All omnivores are diurnal (A) = All nocturnal are diurnal (A)

Verification:
✓ Conclusion I: "All nocturnal are diurnal" - FOLLOWS (direct rule application)
✓ Conclusion II: "Some diurnal are nocturnal" - FOLLOWS (if all A are C, then some C are A)

Answer: Both conclusions I and II follow

Question 3

Statements: All writers are athletes. All athletes are lawyers. Conclusions: I. All writers are lawyers. II. Some lawyers are writers.
Venn Diagram Method:
Draw three circles for writers, athletes, and lawyers.

Step 1: "All writers are athletes" → Circle of writers completely inside athletes
Step 2: "All athletes are lawyers" → Circle of athletes completely inside lawyers
Step 3: Result: writers ⊂ athletes ⊂ lawyers

Analytical Method (A + A = A):
All writers are athletes (A) + All athletes are lawyers (A) = All writers are lawyers (A)

Verification:
✓ Conclusion I: "All writers are lawyers" - FOLLOWS (direct rule application)
✓ Conclusion II: "Some lawyers are writers" - FOLLOWS (if all A are C, then some C are A)

Answer: Both conclusions I and II follow

Question 4

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

Analytical Method (E + A = O*):
No versatile is a valuable (E) + All valuable are reliable (A) = Some reliable are not versatile (O*)

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

Answer: Only conclusion II follows

Question 5

Code Key: @ = All, # = Some, $ = No, & = are A = doctors, B = professionals, C = graduates Coded Statements: @ A & B # B & C Decoded Conclusions: I. Some doctors are graduates. II. All graduates being doctors is a possibility.
Decoding Process:

Step 1: Decode the statements
@ A & B → All doctors are professionals
# B & C → Some professionals are graduates

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 doctors are graduates" - NOT DEFINITE
✓ Conclusion II: "All graduates being doctors 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 6

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

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

Analytical Method:
All tools are devices (A) + No devices is a machines (E) = A + E = E = No tools is a machines
By conversion: No machines is a tools

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 7

Statements: No reliable is a durable. All innovative are durable. Conclusions: I. No durable is a reliable. II. No innovative is a reliable. III. Some durable are not reliable.
Immediate vs Mediate Inference:

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

Checking Each Conclusion:

Conclusion I: "No durable is a reliable" - IMMEDIATE INFERENCE
Conversion of "No reliable is a durable" - FOLLOWS

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

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

Answer: All conclusions I, II and III follow

Question 8

Statements: All musicians are nurses. Some musicians are doctors. Conclusions: I. Some nurses are doctors. II. All nurses being doctors is a possibility. III. Some doctors are nurses.
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 musicians are nurses" → musicians DISTRIBUTED, nurses UNDISTRIBUTED
Statement 2: "Some musicians are doctors" → 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 nurses are doctors" - FOLLOWS
✓ Conclusion II: "All nurses being doctors is a possibility" - No negatives exist - FOLLOWS
✓ Conclusion III: "Some doctors are nurses" - Conversion of I - FOLLOWS

Answer: All conclusions I, II and III follow

Question 9

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

Analytical Method (E + A = O*):
No principles is a methods (E) + All methods are models (A) = Some models are not principles (O*)

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

Answer: Only conclusion II follows

Question 10

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 11

Statements: Some birds are omnivores. All omnivores are mammals. No mammals is a domestic. All domestic are amphibians. Conclusions: I. Some birds are mammals. II. No omnivores is a domestic. III. Some amphibians are not mammals.
Complex Multi-Statement Analysis:

Statement Chain:
1. Some birds are omnivores → Partial overlap
2. All omnivores are mammals → omnivores inside mammals
3. No mammals is a domestic → mammals and domestic separate
4. All domestic are amphibians → domestic inside amphibians

Checking Each Conclusion:

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

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

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

Answer: All conclusions I, II and III follow

Question 12

Statements: All ornaments are furniture. Some ornaments are tools. Conclusions: I. Some furniture are tools. II. All furniture being tools is a possibility. III. Some tools are furniture.
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 ornaments are furniture" → ornaments DISTRIBUTED, furniture UNDISTRIBUTED
Statement 2: "Some ornaments are tools" → 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 furniture are tools" - FOLLOWS
✓ Conclusion II: "All furniture being tools is a possibility" - No negatives exist - FOLLOWS
✓ Conclusion III: "Some tools are furniture" - Conversion of I - FOLLOWS

Answer: All conclusions I, II and III follow

Question 13

Statements: Some pharmacists are athletes. Some athletes are nurses. Conclusions: I. Some pharmacists are nurses. II. No pharmacists is a nurses.
Venn Diagram Method:
Step 1: "Some pharmacists are athletes" → pharmacists and athletes overlap partially
Step 2: "Some athletes are nurses" → athletes and nurses overlap partially
Step 3: Multiple possibilities exist:
- pharmacists and nurses may overlap (some A are C)
- pharmacists and nurses may be separate (no A is C)
- pharmacists and nurses may partially overlap

Analytical Method:
I + I combination gives NO definite conclusion.
The overlapping portions may or may not be the same part of athletes.

Verification:
✗ Conclusion I: "Some pharmacists are nurses" - NOT DEFINITE (possible but not certain)
✗ Conclusion II: "No pharmacists is a nurses" - NOT DEFINITE (possible but not certain)

Answer: Neither conclusion I nor II follows

Question 14

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 15

Statements: All nocturnal are birds. Some birds are wild. No wild is a warm-blooded. Conclusions: I. Some nocturnal are not warm-blooded. II. Some birds are not warm-blooded. III. No warm-blooded is a wild.
Step-by-Step Analysis:

Statement 1: All nocturnal are birds → nocturnal inside birds
Statement 2: Some birds are wild → birds and wild overlap
Statement 3: No wild is a warm-blooded → wild and warm-blooded separate

Checking Conclusions:

Conclusion I: "Some nocturnal are not warm-blooded"
Cannot determine relationship between nocturnal and warm-blooded - NOT PROVEN

Conclusion II: "Some birds are not warm-blooded"
Some birds are wild (given) + No wild is warm-blooded (given)
Those birds which are wild cannot be warm-blooded - FOLLOWS

Conclusion III: "No warm-blooded is a wild"
Conversion of "No wild is a warm-blooded" - FOLLOWS

Answer: Conclusions II and III follow

Question 16

Statements: All reptiles are diurnal. All diurnal are birds. Conclusions: I. All reptiles are birds. II. Some birds are reptiles.
Venn Diagram Method:
Draw three circles for reptiles, diurnal, and birds.

Step 1: "All reptiles are diurnal" → Circle of reptiles completely inside diurnal
Step 2: "All diurnal are birds" → Circle of diurnal completely inside birds
Step 3: Result: reptiles ⊂ diurnal ⊂ birds

Analytical Method (A + A = A):
All reptiles are diurnal (A) + All diurnal are birds (A) = All reptiles are birds (A)

Verification:
✓ Conclusion I: "All reptiles are birds" - FOLLOWS (direct rule application)
✓ Conclusion II: "Some birds are reptiles" - FOLLOWS (if all A are C, then some C are A)

Answer: Both conclusions I and II follow

Question 17

Statements: All invertebrates are nocturnal. Some invertebrates are amphibians. Conclusions: I. Some nocturnal are amphibians. II. All nocturnal being amphibians is a possibility. III. Some amphibians are nocturnal.
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 invertebrates are nocturnal" → invertebrates DISTRIBUTED, nocturnal UNDISTRIBUTED
Statement 2: "Some invertebrates are amphibians" → 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 nocturnal are amphibians" - FOLLOWS
✓ Conclusion II: "All nocturnal being amphibians is a possibility" - No negatives exist - FOLLOWS
✓ Conclusion III: "Some amphibians are nocturnal" - Conversion of I - FOLLOWS

Answer: All conclusions I, II and III follow

Question 18

Statements: Some valuable are beautiful. Some beautiful are efficient. Conclusions: I. Some valuable are efficient. II. No valuable is a efficient.
Venn Diagram Method:
Step 1: "Some valuable are beautiful" → valuable and beautiful overlap partially
Step 2: "Some beautiful are efficient" → beautiful and efficient overlap partially
Step 3: Multiple possibilities exist:
- valuable and efficient may overlap (some A are C)
- valuable and efficient may be separate (no A is C)
- valuable and efficient may partially overlap

Analytical Method:
I + I combination gives NO definite conclusion.
The overlapping portions may or may not be the same part of beautiful.

Verification:
✗ Conclusion I: "Some valuable are efficient" - NOT DEFINITE (possible but not certain)
✗ Conclusion II: "No valuable is a efficient" - NOT DEFINITE (possible but not certain)

Answer: Neither conclusion I nor II follows

Question 19

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

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

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

Answer: Only conclusion II follows

Question 20

Statements: All patterns are methods. Some methods are principles. No principles is a frameworks. Conclusions: I. Some patterns are not frameworks. II. Some methods are not frameworks. III. No frameworks is a principles.
Step-by-Step Analysis:

Statement 1: All patterns are methods → patterns inside methods
Statement 2: Some methods are principles → methods and principles overlap
Statement 3: No principles is a frameworks → principles and frameworks separate

Checking Conclusions:

Conclusion I: "Some patterns are not frameworks"
Cannot determine relationship between patterns and frameworks - NOT PROVEN

Conclusion II: "Some methods are not frameworks"
Some methods are principles (given) + No principles is frameworks (given)
Those methods which are principles cannot be frameworks - FOLLOWS

Conclusion III: "No frameworks is a principles"
Conversion of "No principles is a frameworks" - FOLLOWS

Answer: Conclusions II and III follow
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