Logical Reasoning - Logical Deduction - Discussion

Discussion Forum : Logical Deduction - Section 4 (Q.No. 11)
Directions to Solve

In each of the following questions, three statements are given followed by four conclusions numbered I, II, III and TV. You have to take the given statements to be true even if they seem to be at variance with commonly known facts and then decide which of the given conclusions logically follows from the given statements disregarding commonly known facts.


11.

Statements: No tree is fruit. All fruits are stones. All stones are rains.

Conclusions:

  1. No stone is tree.
  2. No rain is tree.
  3. Some rains are fruits.
  4. Some rains are trees.

Only either II or III, and I follow
None follows
Only either II or IV, and III follow
All follow
None of these
Answer: Option
Explanation:

No tree is fruit. All fruits are stones.

Since the middle term 'fruits' is distributed twice, the conclusion must be particular.

Since one premise is negative, the conclusion must be negative. So, it follows that

'Some stones are not trees'.

All fruits are stones. All stones are rains.

Clearly, it follows that 'All fruits are rains'. III is the converse of this conclusion and so it holds.

No tree is fruit, All fruits are rains.

As discussed above, the conclusion must be particular negative and should not contain the middle term. So, it follows that 'Some rains are not trees'. However, II and IV involve only the extreme terms and form a complementary pair. Thus, either II or IV follows.

Discussion:
5 comments Page 1 of 1.

Manish said:   7 years ago
Conclusion one also is correct.

Please explain me.

Sentry said:   9 years ago
Why the conclusion 1 is false? Can anyone explain?

Maneesh said:   9 years ago
I can not understand this question please explain it in easy way.

Rash said:   1 decade ago
It means.

1. III with II.
OR.
2. III with IV.

Hiro said:   1 decade ago
Since in English is not my first language, I am struggling to understand "Only either II or IV, and III follow" Anyone explain better?

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