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Question

The statements below are followed by two conclusions labeled I and II. Assuming that the information in the statements is true, even if it appears to be at variance with generally established facts, decide which conclusion(s) logically and definitely follow(s) from the information given in the statements.

Statements:

1) All butterflies are reptiles.

2) All reptiles are mammals.

Conclusion:

I. All mammals are butterflies.

II. All butterflies are mammals.

The correct answer is

Only conclusion II follows.

Understanding Syllogism Statements and Conclusions

This question asks us to analyze given statements and determine which of the provided conclusions logically follow. This type of problem is known as a syllogism in logical reasoning. We must strictly adhere to the information given in the statements, even if it contradicts real-world knowledge.

Analyzing the Statements

We have two statements:

  1. All butterflies are reptiles.
  2. All reptiles are mammals.

Let's represent these relationships:

  • Statement 1: If something is a butterfly, then it is a reptile. (Butterflies $\rightarrow$ Reptiles)
  • Statement 2: If something is a reptile, then it is a mammal. (Reptiles $\rightarrow$ Mammals)

Combining the Statements

We can combine these two statements. If all butterflies belong to the set of reptiles, and all reptiles belong to the set of mammals, then it must be true that all butterflies also belong to the set of mammals.

Think of it like sets:

  • The set of Butterflies is entirely inside the set of Reptiles.
  • The set of Reptiles is entirely inside the set of Mammals.

This implies that the set of Butterflies is entirely inside the set of Mammals.

So, from the statements, we can logically deduce: All butterflies are mammals.

Evaluating the Conclusions

Now let's look at the given conclusions:

Conclusion I: All mammals are butterflies.

Based on our deduction that all butterflies are mammals, does it mean all mammals are butterflies? Not necessarily. The combined statements tell us that the set of butterflies is a subset of the set of mammals. There might be many mammals that are not reptiles (and thus not butterflies). For example, based on the statements, a cow could be a mammal, but it doesn't have to be a reptile or a butterfly.

Therefore, Conclusion I does not logically follow from the given statements.

Conclusion II: All butterflies are mammals.

As we deduced from combining Statement 1 (All butterflies are reptiles) and Statement 2 (All reptiles are mammals), this conclusion logically and definitely follows.

If every single butterfly is a reptile, and every single reptile is a mammal, then it is unavoidable that every single butterfly is also a mammal.

Therefore, Conclusion II logically follows from the given statements.

Final Decision

Based on the analysis, only Conclusion II logically follows from the statements.

The correct option is the one stating that only conclusion II follows.

Revision Table: Syllogism Analysis

Statement/Conclusion Relationship Logical Follows? Explanation
Statement 1 All Butterflies $\rightarrow$ Reptiles Given Accepted as true.
Statement 2 All Reptiles $\rightarrow$ Mammals Given Accepted as true.
Combined Logic All Butterflies $\rightarrow$ Mammals Yes Derived from Statement 1 and 2.
Conclusion I All Mammals $\rightarrow$ Butterflies No Converse is not necessarily true. Mammals could exist that are not Butterflies.
Conclusion II All Butterflies $\rightarrow$ Mammals Yes Directly follows from the combined logic of statements 1 and 2.

Additional Information: Basics of Syllogisms

Syllogisms are a form of logical argument that apply deductive reasoning to arrive at a conclusion based on two or more propositions that are asserted or assumed to be true. The structure is typically: Major Premise, Minor Premise, Conclusion.

Key principles in syllogisms like this:

  • All A are B: This means the set of A is a subset of the set of B. It does NOT mean All B are A.
  • Chain Rule: If All A are B, and All B are C, then it logically follows that All A are C. (This is what we saw with Butterflies, Reptiles, and Mammals).
  • Assumption of Truth: In syllogism problems, you must assume the statements are true, regardless of real-world facts.

Understanding these basic rules helps in correctly determining which conclusions are logically valid deductions from the given statements.

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Important Questions from Syllogism

  1. Read the given statements and conclusions carefully. Assuming that the information given in the statements 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:

    Some students are players.

    All players are male.

    Conclusions:

    I. All males are players.

    II. Some males are students.

  2. Read the given statements and conclusions carefully. Assuming that the information given in the statements 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:

    No creative is an employer.

    All experts are creative.

    All workers are experts.

    Conclusions:

    I. No employer is an expert.

    II. No worker is an employer.

  3. Read the given statements and conclusions carefully. Assuming that the information given in the statements 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:

    Some actors are choreographers.

    All choreographers are producers.

    Not a single producer is a director.

    Conclusions:

    I. Some actors are directors.

    II. Not a single actor is a director.

  4. Read the given statements and conclusions carefully. Assuming that the information given in the statements 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 : 

    1. All flowers are tulips.

    2. No tulips are whites.

    Conclusions :

    I. All tulips are flowers.

    II. Some tulips are whites.

  5. Read the given statements and conclusions carefully. Assuming that the information given in the statements 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 rats are dogs.

    Some rats are hens.

    Conclusions:

    I. Some rats are dogs.

    II. Some hens are rats.

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