ln the following question, two statements are given followed by four conclusions. Taking the given statements to be true, decide which of the given conclusions logically follows from the given statements:

Statements: Some rivers are plateau. No plateau is mountain.
Conclusions:
I. Some plateau are rivers.
II.Some mountains are rivers.
III.Some rivers are not mountains.
IV. All mountains are rivers.

The given statements can be represented in the following basic diagram

From the above,

Conclusion I, affirmative, follows. Conclusion II, affirmative, does not follow. Conclusion III, negative, follows.Conclusion IV, affirmative, does not follow. Here, a negative conclusion follows from the basic diagram. The negation of it is “All rivers are mountains”. This cannot be represented in any alternate diagram. Hence, only I and III follow.