Identify what you can properly conclude from the given premises: P: not A → B P: A → not Z P: not Z → F C: ?

Max-Youngquist September 6, 2018

@alaneekonomou the first step is to write out all premises and their contrapositives:

1) not A ==> B
not B ==> A

2) A ==> not Z
Z ==> not A

3) not Z ==> F
not F ==> Z

Then, for each answer choice, we see if we can build a bridge by chaining premises/contrapositives together to get from the sufficient condition to the necessary condition listed in the answer choice.

So for (A): B ==> not F, you'll notice we don't have a premise or contrapositive containing B ==>, so (A) is wrong.

(B): not B ==> F, starting at the contrapositive of premise 1), we have not B ==> A ==> not Z ==> F, so (B) is correct.

I hope that helps!

NicholasSisto December 20, 2019

This did help. Thank you.

Robert November 10, 2020

What class is this from? It's like reading Greek to me