Use Venn diagrams to determine whether the following argumen

Use Venn diagrams to determine whether the following arguments are valid or invalid from the Boolean standpoint. It is false that all inhabitants of Pluto are extraterrestrials. Therefore, no inhabitants of Pluto are extraterrestrials. Some works of fiction are not written by human beings. So, it is false that no works of fiction written by human beings.

Solution

It is false that all inhabitants of Pluto are extraterrestrials; Since this is false add a not to the beginning of the statement which makes it : not all inhabitants of Pluto are extraterrestrials which means:
some (> 0) inhabitants are not extraterrestrials too and the remaning are extraterrestrials;
Which means that there are inhabitnats of Pluto that are extrateresstrials as well as non extraterrestrials;
Thus the conclusions that no inhabitants of Pluto are extraterrestrials is false;

9) some works of fiction are not written by human beings; It means that even non human beings have written fiction works. Thus, both humans and non humans have written works of fiction;
Thus it is false to say that no works of fiction are written by human beings

Hence the conclusion that  it is false to say that no works of fiction are written by human beings is TRUE!