Logical Deduction test

1.

Directions(Qn 1- Qn 2): 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.

Statements: Raman is always successful. No fool is always successful.
Conclusions:
I. Raman is a fool.
II. Raman is not a fool.

Answer: Option B

Explanation:

Since both the premises are universal and one premise is negative, the conclusion must be universal negative and should not contain the middle term. So, only II follows.

2.

Statements: All men are dogs. All dogs are cats.
Conclusions:
I. All men are cats.
II. All cats are men.

Answer: Option A

Explanation:

Since both the premises are universal and affirmative, the conclusion must be universal affirmative. However, conclusion II, being an A-type proposition, distributes the term ‘cats’.Since the term ‘cats’ is distributed in II without being distributed in any of the premises, so conclusion II cannot follow. Thus, only I follows.

3.

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

  1. Rahul is not a donkey.
  2. All men are not Rahul.
Answer: Option A

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: All trucks fly. Some scooters fly.

Conclusions:

  1. All trucks are scooters.
  2. Some scooters do not fly.
Answer: Option D

Explanation:

Since the middle term ‘fly’ is not distributed even once in the premises, no definite conclusion follows.

5.

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

Conclusions:

  1. Some students are boys.
  2. Some teachers are students.
Answer: Option A

Explanation:

Since both the premises are particular, no definite conclusion follows. However, I is the converse of the second premise and thus it holds.

7.

Statements :

Some soldiers are famous
Some soldiers are intelligent
Conclusions :
I. Some soldiers are either famous or intelligent
II. Some soldiers are neither famous nor intelligent
Answer: Option D
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