Statements: Some tapes are discs. Some discs are cassettes. Some cassettes are songs.

Conclusions:

1. Some songs are discs.
2. Some cassettes are tapes.
3. Some songs are tapes.
4. No song is a disc.

Since one premise is particular, the conclusion must be particular and should not contain the middle term. So, it follows that 'Some papers are bats'. III is the converse of this conclusion and so it holds.

All cats are bats. No bat is horse.

Since both the premises are universal and one premise is negative, the conclusion must be universal negative and should not contain the middle term. So, it follows that 'No cat is horse'. II is the converse of this conclusion and so it holds.

Some papers are bats. No bat is horse.

Since one premise is particular and the other negative, the conclusion must be particular negative and should not contain the middle term. So, it follows that 'Some papers are not horses'.

Since the middle term 'buildings' is distributed twice and one premise is negative, the conclusion must be particular negative and should not contain the middle term.

So, it follows that 'Some windows are not toys'.

Some tigers are toys. No toy is building.

Since one premise is particular and the other premise is negative, the conclusion must be particular negative and should not contain the middle term. So, it follows that 'Some tigers are not buildings'.

No man is sky. No sky is road.

Since both the premises are negative, no definite conclusion follows.

No man is sky. Some men are roads.

Since one premise is particular and the other negative, the conclusion must be particular negative and should not contain the middle term. So, it follows that 'Some roads are not skies'.

No sky is road. Some men are roads.

As discussed above, it follows that 'Some men are not skies'.

Hence, only II follows.

No paper is pen. No pen is pencil.

Since both the premises are negative, no definite conclusion follows.

All erasers are papers. No paper is pen.

Since both the premises are universal and one premise is negative, the conclusion must be universal negative and should not contain the middle term. So, it follows that 'No eraser is pen'. III is the converse of this conclusion and so it holds.

Hence, only I and III follow.

All myths are fictions. No fiction is novel.

Since both the premises are universal and one premise is negative, the conclusion must be universal negative and should not contain the middle term. So, it follows that 'No myth is novel'. Thus, I follows.

No fiction is novel. All novels are stories.

Since the middle term 'novels' is distributed twice in the premises, the conclusion must be particular. Since one premise is negative, the conclusion must be negative.

So, it follows that 'Some stories are not fictions'.

Hence, only I and III follow.

Since both the premises are negative, no definite conclusion follows.

No fruit is window. All windows are chairs.

Since the middle term 'windows' is distributed twice and one premise is negative, the conclusion must be particular negative. So, it follows that 'Some chairs are not fruits'.

So, both of them hold.

All fruits are books. All books are buses.

Since both the premises are universal and affirmative, the conclusion must be universal affirmative and should not contain the middle term. So, it follows that 'All fruits are buses'. Thus, IV follows.

All jungles are buses. All books are buses.

Since the middle term 'buses' is not distributed ever once in the premises, no definite conclusion follows.

All fruits are buses. All books are buses.

As discussed above, no definite conclusion can be drawn.

All jungles are buses. All fruits are buses.

Again, no definite conclusion follows.