IndiaBIX

Logical Reasoning - Logical Deduction

Exercise : Logical Deduction - Section 1
Directions to Solve

In each question below are given two statements followed by two conclusions numbered I and II. You have to take the given two statements to be true even if they seem to be at variance from commonly known facts. Read the conclusion and then decide which of the given conclusions logically follows from the two given statements, disregarding commonly known facts.

Give answer:

  • (A) If only conclusion I follows
  • (B) If only conclusion II follows
  • (C) If either I or II follows
  • (D) If neither I nor II follows and
  • (E) If both I and II follow.

31.

Statements: All windows are doors. No door is wall.

Conclusions:

  1. No window is wall.
  2. No wall is door.
Only conclusion I follows
Only conclusion II follows
Either I or II follows
Neither I nor II follows
Both I and II follow
Answer: Option
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,
32.

Statements: Most teachers are boys. Some boys are students.

Conclusions:

  1. Some students are boys.
  2. Some teachers are students.
Only conclusion I follows
Only conclusion II follows
Either I or II follows
Neither I nor II follows
Both I and II follow
Answer: Option
Explanation:
Since both the premises are particular, no definite conclusion follows. However, I is the converse of the second premise and thus it holds.
33.

Statements: No man is a donkey. Rahul is a man.

Conclusions:

  1. Rahul is not a donkey.
  2. All men are not Rahul.
Only conclusion I follows
Only conclusion II follows
Either I or II follows
Neither I nor II follows
Both I and II follow
Answer: Option
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.
34.

Statements: Some books are pens. No pen is pencil.

Conclusions:

  1. Some books are pencils.
  2. No book is pencil.
Only conclusion I follows
Only conclusion II follows
Either I or II follows
Neither I nor II follows
Both I and II follow
Answer: Option
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.
35.

Statements: All men are married. Some men are educated.

Conclusions:

  1. Some married are educated.
  2. Some educated are married.
Only conclusion I follows
Only conclusion II follows
Either I or II follows
Neither I nor II follows
Both I and II follow
Answer: Option
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.
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers