- Fri Aug 03, 2018 7:31 pm
Answer choice (B) is simply something we cannot know one way or the other, meaning it doesn't HAVE to be true (and thus is the exception to Must here), but it COULD be true. So it wouldn't work as the correct answer for Cannot Be True either, since it is possible. Put another way: it lives somewhere in between those two absolutes—Must and Cannot—and therefore doesn't represent either one.
A Cannot answer for this stimulus would be anything that directly contradicts a truth we know. So instead of saying, in (A), some shy people are extroverts, a Cannot Be True statement would be "No shy people are extroverts" or "No extroverts are shy" (note that that's the opposite of (E) for this question). So Cannot has to entirely disagree with what we know, and thus be impossible (unlike (B) which, again, IS possible).
The contrapositive idea with "not" is related to the two "all" statements, where if you're not an extrovert then you're not exuberant and thus you're not an actor. You could still be shy, of course, since some shy people may not be actors (all we know is that some shy people are actors). "Some" and "most" ideas don't have contrapositives because they aren't absolute enough for us to conclude additional absolutes from them, like "some are" doesn't necessarily mean "some are not," etc.
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