Engineering Quantitative Aptitude English Reasoning General Knowledge Coding Others

Quiz: Logical Deduction - Section 2

To View Tricks: Login Required

Number of Questions: 11

Question: 6 -

Statements: Some houses are offices. Some offices are schools.

Conclusions:

  1. Some schools are houses.
  2. Some offices are houses.
  3. No house is school.
  4. Some schools are offices.

Options:

  1. Only I and IV follow

  2. Only either III or IV, and I follow

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

  4. Only II and III follow

    5. Answer:

    Only II and IV and either I or III follow.
    Solution:

    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: 7 -

Statements: Some bags are pockets. No pocket is a pouch.

Conclusions:

  1. No bag is a pouch.
  2. Some bags are not pouches.
  3. Some pockets are bags.
  4. No pocket is a bag,

Options:

  1. Only I and III follow

  2. Only either I or IV follows

  3. None follows

  4. Only II and III follow

    5. Answer:

    Only II and III follow
    Solution:

    Since one premise is particular and the other negative, the conclusion must be particular negative and should not contain the middle term. So, II follows. III is the converse of the first premise and thus it also holds.

Question: 8 -

Statements: All branches are flowers. All flowers are leaves.

Conclusions:

  1. All branches are leaves.
  2. All leaves are branches.
  3. All flowers are branches.
  4. Some leaves are branches.

Options:

  1. None follows

  2. All follow

  3. Only II and III follow

  4. Only I and IV follow

    5. Answer:

    Only I and IV follow
    Solution:

    Since both the premises are universal and affirmative, the conclusion must be universal affirmative and should not contain the middle term. So, it follows that 'All branches are leaves'. Thus, I follows. IV is the converse of this conclusion and so it also holds.

Question: 9 -

Statements: All aeroplanes are trains. Some trains are chairs.

Conclusions:

  1. Some aeroplanes are chairs.
  2. Some chairs are aeroplanes.
  3. Some chairs are trains.
  4. Some trains are aeroplanes.

Options:

  1. Only I and II follow

  2. Only II and III follow

  3. None follows

  4. Only III and IV follow

    5. Answer:

    Only III and IV follow
    Solution:

    Since the middle term 'trains' is not distributed even once in the/premises, no definite conclusion follows. However, III is the converse of the second premise while IV is the converse of the first premise. So, both of them hold.

Question: 10 -

Statements: All politicians are honest. All honest are fair.

Conclusions:

  1. Some honest are politicians.
  2. No honest is politician.
  3. Some fair are politicians.
  4. All fair are politicians.

Options:

  1. None follows.

  2. Only I and II follow.

  3. Only I and III follow

  4. Only I follows.

    5. Answer:

    Only I and III follow
    Solution:

    Clearly, it follows that 'All politicians are fair'. I is the converse of the first premise, while III is the converse of the above conclusion. So, both I and III hold.