In this syllogism based logical reasoning question, two statements about matchboxes, lighters, and fire are given, followed by two conclusions I and II. You must assume the statements are logically true, even if they do not match real world facts, and then decide which conclusions follow. Statement I: All matchboxes are lighters. Statement II: Some fire is made using matchboxes. Conclusion I: No lighters are related to fire. Conclusion II: All fire is caused by lighters.

Difficulty: Easy

Correct Answer: Neither conclusion I nor conclusion II follows

Explanation:


Introduction / Context:
This question tests basic understanding of categorical logic using the standard structure of statements and conclusions. We are given relationships between three sets: matchboxes, lighters, and fire. The task is to see what must be true based only on the given statements. Such questions are often solved using Venn diagrams that represent each category as a circle and then checking whether a conclusion always holds.


Given Data / Assumptions:
- Statement I: All matchboxes are lighters, so the set of matchboxes lies completely inside the set of lighters.
- Statement II: Some fire is made using matchboxes, meaning there is at least one case that belongs to both the set fire and the set matchboxes.
- From Statement I and II combined, that same element of matchboxes and fire must also belong to lighters.
- Conclusion I says that no lighters are related to fire, and Conclusion II says that all fire is caused by lighters.


Concept / Approach:
Translate the statements into set language. "All matchboxes are lighters" means matchbox set is a subset of lighter set. "Some fire are matchboxes" means the intersection of fire and matchbox sets is non empty. Using these relationships, we can infer how fire and lighters are connected. Then we check each conclusion: a universal negative like "no lighters are fire" and a universal positive like "all fire are lighters" must be tested against all possible configurations that satisfy the statements.


Step-by-Step Solution:
Step 1: Let M represent matchboxes, L represent lighters, and F represent fire. Step 2: From Statement I, M ⊆ L. This means that every matchbox is also a lighter. Step 3: From Statement II, some F are M, which means there exists at least one element that is both in F and in M. Symbolically, F ∩ M is non empty. Step 4: Because M is a subset of L, any element that is in M must also be in L. Therefore, the element that lies in F ∩ M also lies in L. Step 5: This means that there is at least one element that belongs to both fire and lighters, so the sets F and L do intersect. Step 6: Conclusion I says "No lighters are fire," which would mean F ∩ L is empty. This contradicts Step 5, so Conclusion I is false. Step 7: For Conclusion II, "All fire are lighters" would mean F ⊆ L. However, we only know that some fire comes from matchboxes and therefore from lighters. There could be other sources of fire that are not lighters at all, so we cannot say that all fire is within the set of lighters.


Verification / Alternative check:
If you draw a Venn diagram, place M entirely inside L and then mark some overlap between M and F. It is clear from the picture that L and F must intersect at least where M lies. This refutes Conclusion I. At the same time, nothing forces the rest of F to lie inside L, so F could extend outside L, which refutes Conclusion II as a universal statement.


Why Other Options Are Wrong:
Option A says only Conclusion I follows, but we have shown that Conclusion I is contradicted by the diagram. Option B says only Conclusion II follows, but there is no guarantee that every fire event comes through a lighter. Option C claims both follow, which is impossible given the direct contradiction. Option E suggests an exclusive or, but neither conclusion follows, so it is also incorrect.


Common Pitfalls:
A tricky point is that students sometimes confuse "some" with "all." Knowing that some fire events involve lighters does not imply every fire involves lighters. Another common error is to misinterpret the universal negative "no lighters are fire" when we clearly have an example where fire, matchbox, and lighter overlap. Always check for the existence of at least one element in the intersection when evaluating such conclusions.


Final Answer:
The correct option is Neither conclusion I nor conclusion II follows, because the statements guarantee that some fire involves lighters, but they neither support a universal negative nor a universal positive relationship between fire and lighters.

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