Question 1
Statements:
Some amphibians are mammals.
All mammals are nocturnal.
Conclusions:
I. All amphibians are nocturnal.
II. Some amphibians are not nocturnal.
Complementary Pair Analysis:
Conclusions I and II form a complementary pair:
- "All amphibians are nocturnal" (A-type)
- "Some amphibians are not nocturnal" (O-type)
These are opposite statements where at least one can be true.
Venn Diagram:
Step 1: "Some amphibians are mammals" → Partial overlap
Step 2: "All mammals are nocturnal" → mammals inside nocturnal
Step 3: The part of amphibians overlapping with mammals is definitely inside nocturnal
Step 4: But we DON'T know about the rest of amphibians
Possible Cases:
Case 1: All of amphibians inside nocturnal → Conclusion I true
Case 2: Some of amphibians outside nocturnal → 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
Conclusions I and II form a complementary pair:
- "All amphibians are nocturnal" (A-type)
- "Some amphibians are not nocturnal" (O-type)
These are opposite statements where at least one can be true.
Venn Diagram:
Step 1: "Some amphibians are mammals" → Partial overlap
Step 2: "All mammals are nocturnal" → mammals inside nocturnal
Step 3: The part of amphibians overlapping with mammals is definitely inside nocturnal
Step 4: But we DON'T know about the rest of amphibians
Possible Cases:
Case 1: All of amphibians inside nocturnal → Conclusion I true
Case 2: Some of amphibians outside nocturnal → 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