Statements: All myths are fictions. No fiction is novel. All novels are stories.
Conclusions:
I. No myth is novel.
II. Some fictions are novels.
III. Some fictions are myths.
IV. Some myths are novels.
III is the converse of first premise and so it holds.
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.