Read the given statements and conclusions carefully. Assuming that the information given in the statement is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.

Statements:

• All ants are black.
• Some blacks are crows.

Conclusions:
(I): All black are ants.
(II): All crows are black.

1. A

   Both conclusions (I) and (II) follow.

2. B

   Neither conclusion (I) nor conclusion (II) follows.

3. C

   Only conclusion (II) follows.

4. D

   Only conclusion (I) follows.

Appeared in: DSSSB 13 August 2024

Explanation

• The problem requires evaluating two conclusions based on two given statements using deductive logic.
• Conclusion (I), 'All black are ants,' is an invalid conversion of the statement 'All ants are black.' A universal affirmative statement ('All A are B') does not imply its converse ('All B are A').
• Conclusion (II), 'All crows are black,' is an invalid inference from 'Some blacks are crows.' A particular statement ('Some') cannot lead to a universal conclusion ('All').
• Since both conclusions represent common logical fallacies, neither can be considered true based on the given information.

Why Other Options Were Wrong

• Option A: This option claims both conclusions are valid. However, as explained, both Conclusion (I) and Conclusion (II) are logically flawed and do not follow from the statements.
• Option C: This option claims Conclusion (II) is valid. This is incorrect because the statement 'Some blacks are crows' does not provide enough information to conclude that 'All crows are black'.
• Option D: This option claims Conclusion (I) is valid. This is incorrect as it represents the fallacy of converting a universal affirmative statement. 'All ants are black' does not mean that the only black things are ants.

Related Visual

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Syllogism and Logical Deduction as background academic context rather than a clinical decision trigger.
• While this is a general intelligence question, the underlying skill of deductive reasoning is critical in nursing.
• Nurses must accurately interpret patient data (symptoms, lab results) to draw logical conclusions about their condition, avoiding fallacies that could lead to incorrect care.
• For example, knowing 'All patients with condition X have symptom Y' does not mean 'All patients with symptom Y have condition X'. This prevents misdiagnosis.

How to Approach the Question

• First, identify the question type. This is a syllogism, a form of logical reasoning.
• Break down the statements. Identify the subjects and predicates (Ants, Black, Crows) and the quantifiers ('All', 'Some').
• Translate the statements into a visual format, such as a Venn diagram, to represent the relationships accurately.
• For 'All A are B', draw circle A entirely inside circle B.
• For 'Some A are B', draw circle A and circle B overlapping.
• Examine each conclusion one by one and test it against your Venn diagram. A conclusion is only valid if it is true in all possible interpretations of the diagram.

Concept Tested & Keywords

• Concept Tested: Syllogism and Logical Deduction
• Stem keywords: All ants are black, Some blacks are crows, Statements, Conclusions
• Lead-in keywords: logically follow(s)

Question ID

QSyoASspWizqFyeTdxJ7wh

Copy ID