Select the answer choice that correctly diagrams the following Sufficient & Necessary statement:Harry could never...

Mehran November 13, 2017

Hi @Nicki6, thanks for your post.

As explained in the correct answer explanation:
Harry could never have defeated Voldemort unless he was the chosen one.

The rule:
Step 1: "Unless" introduces a necessary condition, so the part of the sentence that follows "unless" will be the necessary condition (here: "he was the chosen one.").

Step 2: Negate the other part of the sentence and make it the sufficient condition (here: negate "Harry could never have defeated Voldemort").

So: DV (defeat Voldemort) ==> CO (chosen one)

Hope this helps!

nicolaf8 December 1, 2017

Do you always negate the sufficient when seeing "unless"?

rearden_mettle April 7, 2018

do you always swap the places when unless is used?

lilsdiamond January 14, 2019

What if the unless is followed by another negation?