Syllogism - Intermediate Level: quantifier logic INTERMEDIATE

Exam-focused quick response training ★ worksheet: 20 intermediate-level syllogism questions. Worksheet 13 of 30 targets quantifier logic. Build proficiency in syllogistic reasoning, deductive arguments, logical premises with detailed solutions. Ideal for mid-level competitive exam preparation.

📝 Worksheet 13 of 30 • 20 questions • ⏱️ Estimated time: 20 minutes • 🎯 Intermediate level

What you'll learn in this worksheet:
Your progress through Syllogism
Worksheet 13 of 30 (43% complete)

Question 1

Identify the logical fallacy in the following argument: All birds can fly. Penguins are birds. Therefore, penguins can fly. What is the primary error in this reasoning?
Fallacy Detection Analysis:

Given Argument:
All birds can fly.
Penguins are birds.
Therefore, penguins can fly.

Type of Fallacy: False Premise Fallacy

Explanation:
Valid syllogism structure (All A are B, C is A → C is B) but premise is false.

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: The first premise is factually incorrect (not all birds can fly)

Question 2

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 3

Code Key: @ = All, # = Some, $ = No, & = are P = cats, Q = dogs, R = pets Coded Statements: @ P & Q # Q & R Decoded Conclusions: I. Some cats are pets. II. All pets being cats is a possibility.
Decoding Process:

Step 1: Decode the statements
@ P & Q → All cats are dogs
# Q & R → Some dogs are pets

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 cats are pets" - NOT DEFINITE
✓ Conclusion II: "All pets being cats 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 4

Statements: All structures are principles. No principles is a patterns. Conclusions: I. No structures is a patterns. II. All patterns being structures is a possibility.
Definite Conclusion Analysis:

Venn Diagram:
Step 1: All structures are principles → structures inside principles
Step 2: No principles is a patterns → principles and patterns completely separate
Step 3: Since structures inside principles, structures also doesn't touch patterns

Analytical Method:
All structures are principles (A) + No principles is a patterns (E) = A + E = E
Result: No structures is a patterns

Checking Conclusions:

Conclusion I: "No structures is a patterns" - DEFINITE CONCLUSION - FOLLOWS

Conclusion II: "All patterns being structures is a possibility"
Since definite negative exists ("No structures is a patterns"), this possibility is IMPOSSIBLE
DOES NOT FOLLOW

Important Rule: When definite negative conclusion exists between terms, positive possibility becomes FALSE.

Answer: Only conclusion I follows

Question 5

Statements: All rare are accessible. Some accessible are beautiful. No beautiful is a sustainable. Conclusions: I. Some rare are not sustainable. II. Some accessible are not sustainable. III. No sustainable is a beautiful.
Step-by-Step Analysis:

Statement 1: All rare are accessible → rare inside accessible
Statement 2: Some accessible are beautiful → accessible and beautiful overlap
Statement 3: No beautiful is a sustainable → beautiful and sustainable separate

Checking Conclusions:

Conclusion I: "Some rare are not sustainable"
Cannot determine relationship between rare and sustainable - NOT PROVEN

Conclusion II: "Some accessible are not sustainable"
Some accessible are beautiful (given) + No beautiful is sustainable (given)
Those accessible which are beautiful cannot be sustainable - FOLLOWS

Conclusion III: "No sustainable is a beautiful"
Conversion of "No beautiful is a sustainable" - FOLLOWS

Answer: Conclusions II and III follow

Question 6

Multi-Dimensional Statements: Dimension 1: All intelligent students are hardworking. Dimension 2: Some hardworking students are successful. Dimension 3: All successful students are wealthy. Dimension 4: No wealthy students is cheap. Conclusions: I. Some intelligent students are wealthy. II. Some successful students are not cheap. III. All intelligent students being successful is a possibility.
Multi-Dimensional Syllogism Analysis:
Tracking multiple attributes/dimensions simultaneously.

Building Logical Chains:
Chain 1: intelligent → hardworking (all), but hardworking → successful (only some)
Chain 2: successful → wealthy (all), wealthy → not cheap (all)

Checking Conclusions:
✗ Conclusion I: "Some intelligent students are wealthy" - Cannot determine - DOES NOT FOLLOW
✓ Conclusion II: "Some successful students are not cheap" - All successful are not cheap - FOLLOWS
✓ Conclusion III: "All intelligent students being successful is a possibility" - No negatives prevent this - FOLLOWS

Answer: Conclusions II and III follow

Question 7

Statements: All concepts are models. All models are strategies. Conclusions: I. All concepts are strategies. II. Some strategies are concepts.
Venn Diagram Method:
Draw three circles for concepts, models, and strategies.

Step 1: "All concepts are models" → Circle of concepts completely inside models
Step 2: "All models are strategies" → Circle of models completely inside strategies
Step 3: Result: concepts ⊂ models ⊂ strategies

Analytical Method (A + A = A):
All concepts are models (A) + All models are strategies (A) = All concepts are strategies (A)

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

Answer: Both conclusions I and II follow

Question 8

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

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

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

Answer: Neither conclusion I nor II follows

Question 9

Statements: Only diurnal are carnivores. All carnivores are mammals. Conclusions: I. All diurnal are mammals. II. Some mammals are diurnal.
Understanding 'Only' Statement:
"Only diurnal are carnivores" means "All carnivores are diurnal" (reversal!)

Conversion:
Original: Only diurnal are carnivores
Converted: All carnivores are diurnal

Venn Diagram:
Step 1: "All carnivores are diurnal" → carnivores inside diurnal
Step 2: "All carnivores are mammals" → carnivores inside mammals
Step 3: carnivores inside both diurnal and mammals

Checking Conclusions:

Conclusion I: "All diurnal are mammals"
We only know carnivores is inside both - diurnal could be larger - DOES NOT FOLLOW

Conclusion II: "Some mammals are diurnal"
All carnivores are diurnal and all carnivores are mammals
The carnivores portion is common to both - FOLLOWS

Answer: Only conclusion II follows

Question 10

Statements: All patterns are concepts. All concepts are theories. Conclusions: I. All patterns are theories. II. Some theories are patterns.
Venn Diagram Method:
Draw three circles for patterns, concepts, and theories.

Step 1: "All patterns are concepts" → Circle of patterns completely inside concepts
Step 2: "All concepts are theories" → Circle of concepts completely inside theories
Step 3: Result: patterns ⊂ concepts ⊂ theories

Analytical Method (A + A = A):
All patterns are concepts (A) + All concepts are theories (A) = All patterns are theories (A)

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

Answer: Both conclusions I and II follow

Question 11

Statements: All appliances are equipment. All equipment are tools. Conclusions: I. All appliances are tools. II. Some tools are appliances.
Venn Diagram Method:
Draw three circles for appliances, equipment, and tools.

Step 1: "All appliances are equipment" → Circle of appliances completely inside equipment
Step 2: "All equipment are tools" → Circle of equipment completely inside tools
Step 3: Result: appliances ⊂ equipment ⊂ tools

Analytical Method (A + A = A):
All appliances are equipment (A) + All equipment are tools (A) = All appliances are tools (A)

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

Answer: Both conclusions I and II follow

Question 12

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

Answer: All conclusions I, II and III follow

Question 13

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

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

Possible Cases:
Case 1: All of valuable inside sustainable → Conclusion I true
Case 2: Some of valuable outside sustainable → 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 14

Temporal Statements: All athletes who train regularly train for more than 6 hours daily. All athletes who win medals are athletes who train regularly. Some athletes who win medals are athletes who become famous. Conclusions: I. Some athletes who become famous train for more than 6 hours daily. II. Some people who train for more than 6 hours daily are athletes who become famous. III. All athletes who become famous are definitely athletes who win medals.
Temporal Syllogism Analysis:
Temporal syllogisms involve time-based conditions integrated with logical statements.

Logical Chain:
All athletes who win medals are athletes who train regularly + All athletes who train regularly train for more than 6 hours daily = All athletes who win medals train for more than 6 hours daily
Some athletes who win medals are athletes who become famous + All athletes who win medals train for more than 6 hours daily = Some athletes who become famous train for more than 6 hours daily

Checking Conclusions:
✓ Conclusion I: "Some athletes who become famous train for more than 6 hours daily" - FOLLOWS
✓ Conclusion II: "Some people who train for more than 6 hours daily are athletes who become famous" - Conversion of I - FOLLOWS
✗ Conclusion III: "All athletes who become famous are definitely athletes who win medals" - Only "some" given, not "all" - DOES NOT FOLLOW

Answer: Only conclusions I and II follow

Question 15

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

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

Possible Cases:
Case 1: All of ideas inside patterns → Conclusion I true
Case 2: Some of ideas outside patterns → 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 16

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

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

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

Answer: Neither conclusion I nor II follows

Question 17

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

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

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

Answer: Only conclusion II follows

Question 18

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

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

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

Answer: Neither conclusion I nor II follows

Question 19

Statements: Only managers are pilots. All pilots are teachers. Conclusions: I. All managers are teachers. II. Some teachers are managers.
Understanding 'Only' Statement:
"Only managers are pilots" means "All pilots are managers" (reversal!)

Conversion:
Original: Only managers are pilots
Converted: All pilots are managers

Venn Diagram:
Step 1: "All pilots are managers" → pilots inside managers
Step 2: "All pilots are teachers" → pilots inside teachers
Step 3: pilots inside both managers and teachers

Checking Conclusions:

Conclusion I: "All managers are teachers"
We only know pilots is inside both - managers could be larger - DOES NOT FOLLOW

Conclusion II: "Some teachers are managers"
All pilots are managers and all pilots are teachers
The pilots portion is common to both - FOLLOWS

Answer: Only conclusion II follows

Question 20

Statements: No invertebrates is a birds. All cold-blooded are birds. Conclusions: I. No birds is a invertebrates. II. No cold-blooded is a invertebrates. III. Some birds are not invertebrates.
Immediate vs Mediate Inference:

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

Checking Each Conclusion:

Conclusion I: "No birds is a invertebrates" - IMMEDIATE INFERENCE
Conversion of "No invertebrates is a birds" - FOLLOWS

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

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

Answer: All conclusions I, II and III follow
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