In question some statements are given followed by two conclusions I and II You have to consider the ...........

Logical Reasoning(SBI-CL) Syllogism

In question, some statements are given, followed by two conclusions I and II. You have to consider the statements to be true, even if they seem to be at variance from commonly known facts. You have to decide which of the given conclusions, if any, follow from the given statements. Indicate your answer.

Statements :

No grasshopper is an insect.

No insect is a bug. All bugs are moths.

Conclusions : I. Some bugs may be grasshoppers. II. All moths being insects is a possibility. III. No bug is a grasshopper.

Either I or III follows

I and III follow

Only I follows

All I, II and III follow

None of these

Explanation:

Analytical Method:
Given Statements:
No grasshopper is an insect.
No insect is a bug.
All bugs are moths.
Given Conclusions:
Some bugs may be grasshoppers.
All moths being insects is a possibility.
No bug is a grasshopper.
Checking Conclusion 1 and 3:
Some bugs may be grasshoppers & No bug is a grasshopper
As we can observe that both S1 and S2 are E-type statements, the middle term ‘insect’ is distributed
twice here. Therefore, we can’t define a definite relationship between these two classes. Clearly,
possibilities do exist between ‘bug’ and ‘grasshopper’.
This confirms that C1 follows but C3 doesn’t.
Checking Conclusion 2:
All moths being insects is a possibility.
Using S3 and S2, we get
Converse of S3 (All bugs are moths) + Converse of S2 (No insect is a bug)
Some moths are bugs + No bug is an insect = Some moths are not insects
Now, when some moths are already not insects, all moths being insects is not
possible.
C2, hence, doesn’t follow.
Evidently, option C is the correct answer.