Justify Formula Drill pg 4-93 #4

[jessicamorehead]

For number 4 on 4-93, the premise is "If E attends, then F attends." The conclusion is "E does not attend." I know the conditional statement would be, E attends --> F attends. The contrapositive of that is F does NOT attend --> E does NOT attend. So how come the correct justifying statement is "F will not attend." Wouldn't that me a mistaken reversal on the conditional statement?


Also, for number 5 on the same page, I am confused on the answer. I said my justifying statement as "More people registered." But the answer is "The number of registered voters did not decrease from the last election." I'm confused how they got to that. Can someone please explain?

Thank you!!
Jessica

[Dave Killoran]

Hey Jessica,

With the E/F one, I'm going to ask you to look at that again. You've got everything right about that, except in thinking that "Not F" is a Mistaken Reversal. Instead, it's precisely because "not F" enacts the contrapositive that it is the answer.

I'm also going to have #5 separated into a different question (maybe added to this, actually: lsat/viewtopic.php?t=7555), just to keep things clean, and then we'll answer that on that thread

Thanks!