10
Q:

Some hills are rivers. Some rivers are desrets. All desrets are roads.

Conclusions:

1. Some roads are rivers

2. Some roads are hills

3. Some deserts are hills

A) None follows B) Only 1 follows
C) Only 1 and 2 follows D) All follow

Answer:   B) Only 1 follows



Explanation:

Some hills are  rivers. Some rivers are deserts.

Since both the premises are particular, no defenite conclusion follows.

 

Some rivers are deserts. All deserts are roads

Since one premise is particular,the conclusion must be particular and should'nt contain the middle term. Since it follows that 'Some rivers are roads'. 1 is the converse of this conclusion and so it holds.