Q: Statements: All windows are doors. No door is wall.
Conclusions:
I. No window is wall.
II. No wall is door.
A. Only conclusion I follows
B. Only conclusion II follows
C. Either I or II follows
D. Both I and II follow
Solution: Since both the premises are universal and one premise is negative, the conclusion must be universal negative. Also, the conclusion should not contain the middle term. So, I follows. However, II is the converse of the second premise and thus it also holds,
Q: Statements: Most teachers are boys. Some boys are students.
Conclusions:
I. Some students are boys.
II. Some teachers are students.
A. Only conclusion I follows
B. Only conclusion II follows
C. Either I or II follows
D. Both I and II follow
Solution: Since both the premises are particular, no definite conclusion follows. However, I is the converse of the second premise and thus it holds.
Q: Statements: No man is a donkey. Rahul is a man.
Conclusions:
I. Rahul is not a donkey.
II. All men are not Rahul.
A. Only conclusion I follows
B. Only conclusion II follows
C. Either I or II follows
D. Both I and II follow
Solution: Since on premise is negative, the conclusion must be negative. Conclusion II cannot follow as it contains the middle term. So, only I follows.
Q: Statements: All men are married. Some men are educated.
Conclusions:
I. Some married are educated.
II. Some educated are married.
A. Only conclusion I follows
B. Only conclusion II follows
C. Either I or II follows
D. Both I and II follow
Solution: Since one premise is particular, the conclusion must be particular and should not contain the middle term. So, I follows. II is the converse of I and thus it also holds.
Q: Statements: Some books are tables. Some tables are mirrors.
Conclusions:
I. Some mirrors are books.
II. No book is mirror.
A. Only conclusion I follows
B. Only conclusion II follows
C. Either I or II follows
D. Both I and II follow
Solution: Since both the premises are particular no definite conclusion follows. However, I and II involve only the extreme terms and form a complementary pair. Thus, either I or II follows.