Logical Reasoning - Logical Deduction - Discussion
Discussion Forum : Logical Deduction - Section 1 (Q.No. 14)
Directions to Solve
In each question below are given two statements followed by two conclusions numbered I and II. You have to take the given two statements to be true even if they seem to be at variance from commonly known facts. Read the conclusion and then decide which of the given conclusions logically follows from the two given statements, disregarding commonly known facts.
Give answer:
- (A) If only conclusion I follows
- (B) If only conclusion II follows
- (C) If either I or II follows
- (D) If neither I nor II follows and
- (E) If both I and II follow.
14.
Statements: Some swords are sharp. All swords are rusty
Conclusions:
- Some rusty things are sharp.
- Some rusty things are not sharp.
Answer: Option
Explanation:
Since one premise is particular, the conclusion must be particular and should not contain the middle term. So, I follows. Since both the premises are affirmative, the conclusion cannot be negative. Thus, II does not follow.
Discussion:
23 comments Page 1 of 3.
Shantanu said:
4 years ago
The statement "Some swords are sharp" only tells about some swords being sharp but it does not imply that some swords are not sharp. This statement is true even if all the swords are sharp. Because if all the swords are sharp, then definitely some swords are sharp. By extension of this logic, all the rusty (things) may also be sharp. Hence conclusion II is not true.
(A conclusion that is false in even one case is basically false overall).
(A conclusion that is false in even one case is basically false overall).
(1)
Vipul said:
10 years ago
Imagine you have 10 swords. All sharp. Some of them are rusty.
So we can say that, some rusty THINGS (i.e Swords) are sharp.
But we cannot say, some rusty things are not sharp. As we don't have any other things which are rusty but not sharp. So II will not follow.
Hope I made it clear.
So we can say that, some rusty THINGS (i.e Swords) are sharp.
But we cannot say, some rusty things are not sharp. As we don't have any other things which are rusty but not sharp. So II will not follow.
Hope I made it clear.
Pawan said:
9 years ago
'Some swords are rusty' implies--->
1. Some swords are rusty
2. Some are not.
Since all swords are sharp, it contains both kind swords (1. Rusty and 2. Non-rusty) Hence,
---> Rusty swords are sharp + "non-rusty swords are sharp", Therefore, conclusion 2 is also implacable.
1. Some swords are rusty
2. Some are not.
Since all swords are sharp, it contains both kind swords (1. Rusty and 2. Non-rusty) Hence,
---> Rusty swords are sharp + "non-rusty swords are sharp", Therefore, conclusion 2 is also implacable.
ViKARLL said:
10 years ago
First conclusion is correct, without dispute.
But there is no way that you can draw a Venn diagram to force the second conclusion to go wrong. So both are valid i.e. both follow, and the answer should be E as everyone above argue. I think, the answer they have given is wrong.
But there is no way that you can draw a Venn diagram to force the second conclusion to go wrong. So both are valid i.e. both follow, and the answer should be E as everyone above argue. I think, the answer they have given is wrong.
(1)
J.Seychell said:
1 decade ago
I think it depends on what is meant by "some swords are sharp". Does it mean 'at least some swords are sharp' or does it mean 'some swords are sharp and some aren't'? If the former is meant, the answer makes logical sense but if it is meant the latter, both will follow.
Sonika singh said:
10 years ago
Both are valid because for the second statement we can take the negation that is:all rusty things are sharp and can make the venn diagram according but then the given statement will be violated so the conclusion 2 follows and thus both are valid.
Swarnna said:
5 years ago
Some swords are sharp means some swords are not sharp, not all swords are rusty so if it does not follow 2nd that means we can't say that all swords are rusty which is a contradiction. So it has to be both.
Roshan said:
1 decade ago
Convert the statement I -- Some sharp are sword = I.
Statement II is A type,
I + A = O.
Some sharp are not rusty thing.
It means both are implicate.
Statement II is A type,
I + A = O.
Some sharp are not rusty thing.
It means both are implicate.
Brandon said:
1 decade ago
Where does it state that "swords" are "things" ?
Technically the conclusions have nothing to do with it, right?
Yes please post a Venn Diagram.
Technically the conclusions have nothing to do with it, right?
Yes please post a Venn Diagram.
Diya said:
1 decade ago
Can anybody please explain the answer logically with the help of venn diagram and not with rules. bcoz I think both should follow.
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