Joan got A's on all her homework assignments, so if she had gotten an A on her term paper, she could pass the course ...

Victoria on June 21, 2021

Hi @amarachicynthia,

Happy to help!

You are correct that the writer simply negated without reversing!

A on term paper --> Pass without presentation
Not pass without presentation --> Not A on term paper

Instead, the writer concludes that, because Joan did not get an A on her term paper, then she will not be able to pass the class without doing the presentation. However, getting an A on her term paper is sufficient, but not necessary, for her to pass without doing the presentation.

This is what answer choice (B) says, just in a more complicated way.

The writer presupposes that: not A on term paper --> not pass without presentation (which is our mistaken negation).

Answer choice (D) is incorrect because it restates the contrapositive we have outlined above. If Joan cannot pass the course without doing the presentation, then she did not get an A on her paper. This is different than saying that, if Joan did not get an A on her term paper, then she will have to do the presentation to pass the course, as the stimulus does.

Hope this helps! Please let us know if you have any further questions.