Logical Deduction(Reasoning Aptitude > Logical Reasoning ) Questions and answers for exam Preparation

Reasoning Aptitude > Logical Reasoning

LOGICAL DEDUCTION MCQs

Total Questions : 508 | Page 46 of 51 pages

Question 451. Statements : All terrorists are guilty. All terrorists are criminals.
Conclusions :
I. Either all criminals are guilty or all guilty are criminals.
II. Some guilty persons are criminals.
III. Generally criminals are guilty.
IV. Crime and guilt go together.

Discuss Question

Answer: Option C. -> Only II follows
Since the middle term 'terrorists' is distributed twice in the premises, the conclusion cannot be universal. So, it follows that 'Some guilty persons are criminals'. Thus, II holds.

Question 452. Statements : Some bottles are drinks. All drinks are cups.
Conclusions :
I. Some bottles are cups.
II. Some cups are drinks.
III. All drinks are bottles.
IV. All cups are drinks.

Discuss Question

Answer: Option A. -> Only I and II follow
Since one premise is particular, the conclusion must be particular and should not contain the middle term. So, it follows that 'Some bottles are cups'. Thus, I follows. II is the converse of the second premise and so it also holds.

Question 453. Statements : Some books are pens. No pen is pencil.
Conclusions :
I. Some pens are books.
II. Some pencils are books.
III. Some books are not pencils.
IV. All pencils are books.

Discuss Question

Answer: Option C. -> Only I and III follow
Since one premise is particular and the other negative, the conclusion must be particular negative and should not contain the middle term. Thus, III follows. I is the converse of the first premise and so it also holds.

Question 454. Statements : Some taxis have horns. Some taxis have lights.
Conclusions :
I. Every taxi has either horn or light.
II. Some taxis have neither light nor horn.
III. Some taxis have horns as well as lights.
IV. No taxi has horn as well as light.

Discuss Question

Answer: Option D. -> Either III or IV follows
Since both the premises are particular, no definite conclusion follows. However, III and IV form a complementary pair. Thus, either III or IV follows.

Question 455. Statements : Some houses are offices. Some offices are schools.
Conclusions :
I. Some schools are houses.
II. Some offices are houses.
III. No house is school.
IV. Some schools are offices.

Only II and III follow
Only I and IV follow
Only either III or IV, and I follow
Only II and IV and either I or III follow.

Discuss Question

Answer: Option D. -> Only II and IV and either I or III follow.
Since both the premises are particular, no definite conclusion follows. However, I and III involve only the extreme terms and form a complementary pair. So, either I or III follows. II is the converse of the first premise while IV is the converse of the second premise. Thus, both of them hold.

Question 456. Statements : Some taxis have horns. Some taxis have lights.
Conclusions :
I. Every taxi has either horn or light.
II. Some taxis have neither light nor horn.
III. Some taxis have horns as well as lights.
IV. No taxi has horn as well as light.

Discuss Question

Question 457. Statements : Some taxis have horns. Some taxis have lights.
Conclusions :
I. Every taxi has either horn or light.
II. Some taxis have neither light nor horn.
III. Some taxis have horns as well as lights.
IV. No taxi has horn as well as light.

Discuss Question

Question 458. Statements : Some taxis have horns. Some taxis have lights.
Conclusions :
I. Every taxi has either horn or light.
II. Some taxis have neither light nor horn.
III. Some taxis have horns as well as lights.
IV. No taxi has horn as well as light.

Discuss Question

Question 459. Statements : All fruits are vegetables. All pens are vegetables. All vegetables are rains.
Conclusions :
I. All fruits are rains.
II. All pens are rains.
III. Some rains are vegetables.

Discuss Question

Answer: Option E. -> All follow
III is the converse of the third premise and so it holds.
All fruits are vegetables. All vegetables are rains.
The conclusion must be universal affirmative and should not contain the middle term.
So, it follows that 'All fruits are rains'. Thus, I follows.
All pens are vegetables. All vegetables are rains.
Clearly, it follows that 'All pens are rains'. Thus, II follows.

Question 460. Statements : Some towels are brushes. No brush is soap. All soaps are rats.
Conclusions :
I. Some rats are brushes.
II. No rat is brush.
III. Some towels are soaps.

Discuss Question

Answer: Option B. -> Only either I or II follows
Some towels are brushes. No brush is soap.
Since one premise is particular and the other negative, the conclusion must be particular negative (O-type) and should not contain the middle term. So, it follows that 'Some towels are not soaps'. No brush is soap. All soaps are rats.
Since the middle term is distributed twice, the conclusion must be particular. Since one premise is negative, the conclusion must be negative. So, it follows that 'Some brushes are not rats'. Since I and II involve the same terms and form a complementary pair, so either I or II follows.