Logical Deduction problems
- 1. Statements: All windows are doors. No door is wall.
Conclusions:
- No window is wall.
- No wall is door.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Both I and II follow
Explanation:
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,
- 2. Statements: Most teachers are boys. Some boys are students.
Conclusions:
- Some students are boys.
- Some teachers are students.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Only conclusion I follows
Explanation:
Since both the premises are particular, no definite conclusion follows. However, I is the converse of the second premise and thus it holds.
- 3. Statements: No man is a donkey. Rahul is a man.
Conclusions:
- Rahul is not a donkey.
- All men are not Rahul.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Only conclusion I follows
Explanation:
Since on premise is negative, the conclusion must be negative. Conclusion II cannot follow as it contains the middle term. So, only I follows.
- 4. Statements: Some books are pens. No pen is pencil.
Conclusions:
- Some books are pencils.
- No book is pencil.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Either I or II follows
Explanation:
As discussed above, the conclusion must be particular negative and should not contain the middle term. So, it follows that 'Some books are not pencils'. However, I and II involve only the extreme terms and form a complementary pair. Thus, either I or II follows.
- 5. Statements: All men are married. Some men are educated.
Conclusions:
- Some married are educated.
- Some educated are married.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Both I and II follow
Explanation:
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.
- 6. Statements: All tubes are handles. All cups are handles.
Conclusions:
- All cups are tubes.
- Some handles are not cups.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Neither I nor II follows
Explanation:
Both the premises are A type propositions. So, in either, the middle term 'handles' forming the predicate is not distributed. Since the middle term is not distributed even once in the premises, no definite conclusion follows
- 7. Statements: No magazine is cap. All caps are cameras.
Conclusions:
- No camera is magazine.
- Some cameras are magazines.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Either I or II follows
Explanation:
As discussed above, the conclusion must be particular negative and should not contain the middle term. So, it follows that 'Some cameras are not magazines'. However, I and II involve only the extreme terms and form a complementary pair. Thus, either I or II follows.
- 8. Statements: All huts are mansions. All mansions are temples.
Conclusions:
- Some temples are huts.
- Some temples are mansions.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Both I and II follow
Explanation:
As discussed above, it follows that 'All huts are temples'. I is the converse of this conclusion and so it holds. II is the converse of the second premise and so it also holds.
- 9. Statements: Some books are tables. Some tables are mirrors.
Conclusions:
- Some mirrors are books.
- No book is mirror.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Either I or II follows
Explanation:
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.
- 10. Statements: All trucks fly. Some scooters fly.
Conclusions:
- All trucks are scooters.
- Some scooters do not fly.
Options- A. Only conclusion I follows
- B. Only conclusion II follows
- C. Either I or II follows
- D. Neither I nor II follows
- E. Both I and II follow Discuss
Correct Answer: Neither I nor II follows
Explanation:
Since the middle term 'fly' is not distributed even once in the premises, no definite conclusion follows.
More in Logical Reasoning:
Programming
Copyright ©CuriousTab. All rights reserved.