Difficulty: Medium
Correct Answer: Only conclusion III follows.
Explanation:
Introduction / Context:
This question tests basic syllogism or statement and conclusion reasoning. We are given two categorical statements about astronomers, scientists, and shopkeepers, and then several possible conclusions. Our task is to assume that both statements are absolutely true and then check, using pure logic, which conclusions must follow in every possible situation that satisfies the statements.
Given Data / Assumptions:
- Statement 1: All astronomers are scientists.
- Statement 2: Some scientists are shopkeepers.
- We treat the word some as meaning at least one.
- No extra facts beyond these statements are to be assumed.
Concept / Approach:
In syllogism questions, the safest method is to visualise or draw simple Venn diagrams and then see what must be true. The structure All A are B means the A circle lies completely inside the B circle. The structure Some B are C means that there is at least one overlapping region common to sets B and C. A conclusion is valid only if it holds in every possible diagram that respects the given statements. If we can imagine even one valid diagram where the conclusion fails, then that conclusion does not logically follow.
Step-by-Step Solution:
Step 1: Represent astronomers (A) and scientists (S) so that all astronomers are inside the set of scientists. This captures Statement 1.
Step 2: Represent shopkeepers (K) such that there is at least one common region between scientists and shopkeepers, because some scientists are shopkeepers as given in Statement 2.
Step 3: Check Conclusion I: All astronomers are shopkeepers. We only know that all astronomers are scientists and that some scientists are shopkeepers. It is possible that the astronomer region lies entirely in the part of scientists that is not shopkeeper. So this need not be true. Conclusion I does not follow.
Step 4: Check Conclusion II: Some shopkeepers are astronomers. From the statements we do not know that any of the scientists who are shopkeepers are astronomers. They may all be scientists who are not astronomers. So this also does not have to be true. Conclusion II does not follow.
Step 5: Check Conclusion III: Some shopkeepers are scientists. This is exactly what Statement 2 says in another wording. If some scientists are shopkeepers, then some shopkeepers are scientists. Hence Conclusion III definitely follows.
Step 6: Check Conclusion IV: All scientists are astronomers. Statement 1 only says that all astronomers are scientists, not the other way around. There can be scientists who are not astronomers. So Conclusion IV does not follow.
Verification / Alternative check:
We can quickly verify by building an example. Suppose there are 10 scientists, of which 2 are astronomers and 3 are shopkeepers, but none of the astronomers are shopkeepers. In that case Statement 1 and Statement 2 are both satisfied. In this scenario, it is still true that some shopkeepers are scientists, but astronomers are not shopkeepers and not all scientists are astronomers. This confirms that only Conclusion III is forced to be true in all valid cases.
Why Other Options Are Wrong:
- Options that include Conclusion I wrongly assume that all astronomers are among the shopkeepers, which is not guaranteed.
- Options that include Conclusion II assume that at least one shopkeeper is definitely an astronomer, which is not forced by the statements.
- Options that include Conclusion IV assume that every scientist must be an astronomer, but the given data never states this.
- The option that claims that the answer cannot be determined ignores the fact that Conclusion III directly restates Statement 2.
Common Pitfalls:
Many students reverse or overextend universal statements. From all astronomers are scientists they incorrectly jump to all scientists are astronomers. Another common mistake is to assume that some scientists are shopkeepers automatically implies some shopkeepers are astronomers, without checking the overlap carefully. Always remember that some does not specify which members of the larger group are involved.
Final Answer:
Therefore, the only conclusion that definitely follows from the given statements is Only conclusion III follows.
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