Logical Deduction - Section 1
Practice and master this topic with our carefully crafted questions.
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.
Statements: All men are married. Some men are educated.
Conclusions:
I. Some married are educated.
II. Some educated are married.
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.
Statements: Some men are educated. Educated persons prefer small families.
Conclusions:
I. All small families are educated.
II. Some men prefer small families.
Since one premise is particular, the conclusion must be particular and should not contain the middle term. Thus, only II follows.
Statements: All educated people read newspapers. Rahul does not read newspaper.
Conclusions:
I. Rahul is not educated.
II. Reading newspaper is not essential to be educated.
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 I follows.
Statements: All pens are chalks. All chairs are chalks.
Conclusions:
I. Some pens are chairs.
II. Some chalks are pens.
Since the middle term 'chalks' is not distributed even once in the premises, no definite conclusion follows. However, II is the converse of the first premise and so it holds.
Statements: Bureaucrats marry only intelligent girls. Tanya is very intelligent.
Conclusions:
I. Tanya will marry a bureaucrat.
II. Tanya will not marry a bureaucrat.
The data does not mention whether all intelligent girls are married to bureaucrats. So, either I or II may follow.
Statements: Some engineers are fools. Anand is an engineer.
Conclusions:
I. Some fools are engineers.
II. Anand is a fool.
Since the middle term 'engineer' is not distributed even once in the premises, no definite conclusion follows. However, I is the converse of the first premise and thus it holds.
Statements: All poles are guns. Some boats are not poles.
Conclusions:
I. All guns are boats.
II. Some boats are not guns.
Clearly, the term 'guns' is distributed in both the conclusions without being distributed in any of the premises. So, neither conclusion follows.
Statements: Many scooters are trucks. All trucks are trains.
Conclusions:
I. Some scooters are trains.
II. No truck is a scooter.
Since the first premise is particular, the conclusion must be particular and should not contain the middle term. Thus, only I follows.
Statements: Some papers are pens. Angle is a paper.
Conclusions:
I. Angle is not a pen.
II. Angle is a pen.
Since the middle term 'papers' is not distributed even once in the premises, no definite conclusion follows. However, I and II involve only the extreme terms and form a complementary pair. Thus, either I or II follows.
Statements: All birds are tall. Some tall are hens.
Conclusions:
I. Some birds are hens.
II. Some hens are tall.
Since the middle term 'tall' is not distributed even once in the premises, no definite conclusion follows. However, II is the converse of the second premise and so it holds.