Question 69

Logical Reasoning Statement and Conclusions Hard

<p>Decide which of the given conclusions logically follow from the given statement(S)</p> <p><strong>Statement:</strong></p> <p>Some metals are alloys.</p> <p>No metal is a stone.</p> <p><strong>Conclusions:</strong></p> <p>I. No alloy is stone.</p> <p>II. Atleast some alloys are metals</p>

(A) Neither conclusion I nor II is true
(B) Only Conclusion&nbsp;II is true
(C) Only Conclusion&nbsp;I is true
(D) Both&nbsp;Only Conclusion I and II are true
View Dynamic Solution & Explanation
Correct Solution: Option B

Step-by-step Solution:

Logical Analysis of Statements and Conclusions

To determine the validity of the conclusions, we can analyze the given statements, often by visualizing them with Venn diagrams.

The Statements:

  1. Some metals are alloys. This means there is an overlap between the set of Metals and the set of Alloys.
  2. No metal is a stone. This means the set of Metals and the set of Stones are completely separate (disjoint).

From these statements, we can visualize a circle for "Metals" and a circle for "Stones" that do not touch. A third circle for "Alloys" must overlap with the "Metals" circle.


Evaluating the Conclusions:

Conclusion I: No alloy is stone.

  • The statements tell us that the part of the "Alloys" circle that intersects with "Metals" cannot be "Stones".
  • However, we have no information about the part of the "Alloys" circle that does not contain "Metals". It is possible for this part of the "Alloys" circle to overlap with the "Stones" circle without violating the initial statements.
  • Since a conclusion must be true in all possible scenarios, and we can imagine a scenario where some alloys are stones, this conclusion does not logically follow. It is only a possibility, not a certainty.
  • Conclusion I is not necessarily true.

Conclusion II: Atleast some alloys are metals.

  • "Atleast some" is logically equivalent to "Some". So the conclusion is "Some alloys are metals".
  • The first statement is "Some metals are alloys". In logic, this is a symmetrical relationship. If some members of group A are also in group B, it is always true that some members of group B are also in group A.
  • This is a direct conversion of the first given statement.
  • Conclusion II is true.

Final Answer

Only Conclusion II logically follows from the given statements.