Hello, I was having some confusion with this question. I found the contrapositives for each one but I ended up choosing D. Could you explain why this is incorrect?
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Hi I would also like an explanation on the contrapositive on the conclusion and whit the structure differs from that of the contrapositive of first premise.
jasminekbond96@gmail.comMay 28, 2020
Hi, I think I might have figured it out somewhat. Let's see how I can explain this:
Okay you have the first premise: X-some-Y Contrapositive: Y-some-X
Conclusion: Z-some-Y Contrapositive: Y-some-Z
The missing premise would have to connect X with Z to make the conclusion follow properly. If you notice, the contrapositive if the first premise (Y-some-X), you can make the assumption that X->Z so you would have:
Y-some-X->Z
So, Y-some-X->Z, when you look at the contrapositive of the conclusion, you see Y-Some -Z and when you flip it back, it's Z-some-Y.
So looking at how it all connects you can assume X->Z to make the conclusion follow. The answer just seems off because it's the contrapositive of the assumed premise:
X->Z Contrapositive: not Z->not X
Side note: the arrows don't point toward "some" the arrows have to point away from "some"
