In the lesson on bi-conditionals (Lesson 7 of 18 in Advanced Logic), we are told that "Alan attends the meeting only if Chris attends the meeting" is expressed as "A>C." I get that. But don't we need another expression that says in effect, "otherwise [or else], Alan does not attend"?
Admin Note: https://classic.7sage.com/lesson/advanced-bi-conditionals/
Given the rule, "If G and S are both in, then W is in," I understand the contrapositive is "If W is out, then G is out or S is out (since both G and S cannot be in). But why doesn't the contrapositive also allow for the possibility that G and S are BOTH out (as well as W being out)?
#help. I was debating between B and E but (wrongly) chose E for two reasons: The tutorial said to choose a choice that doesn't attack the premise. IMHO, both B and E do that, but I chose E because it showed that in actuality the premise had been invalidated before, whereas B did not. Also, the explanation implies that E has nothing to do with the premise, but E refers back to the premise in the same way that B does. E refers to the sentence, "On the other hand, if the flowers had been sent by someone who does not know Drew well, then that person would have sent a signed card with the flowers." Am I nuts?
I cannot for the life of me understand how to arrive at the answer to this question. I mapped the biologist's reasoning as Deforestation>/Koalas, and I mapped the politician's as K>/Deforestation. So in order for the politician to be right, we must meet the sufficient condition; the only way we can know the politician is wrong is if we either have K>Deforestation or (the contrapositive being wrong) Deforestation>K. I didn't see either of these options, and indeed, the correct answer choice says /Deforestation>/Koalas, which IS the correct contrapositive (so it agrees with the politician).
Thank you!
Admin note: Edited the title. Please use the format "PT#.S#.Q# - brief description of question"
How to find the background info vs. premise vs. conclusion in PT4.S1.Q11.
I could not for the life of me figure out which sentences in the stimulus were the premises and which were the conclusion (and perhaps which was merely background info):
Can someone please clue me in?
Thanks so much.
I think I understand your explanation, You wrote:
"In this case the 'some people say' is needed in the argument if not the (but they are wrong) and the premise(s) that follow would not make as much sense.
Did you mean to write:
"In this case the 'some people say' is needed in the argument because if it wasn't there, the 'but they are wrong' phrase and the premise(s) that follow would not make as much sense."?
Thank you.
Ha. So true. Thank you for pointing that out.
lizmorrill185
In lesson 16 of 18, we are told that "some people say" is not part of the argument, but in the explanation to Exercise 3 in Lesson 16, we are told the phrase does introduce the author's argument. Could we get a definitive answer from 7Sage or LSAC about this seeming contradiction?
Admin Note: https://classic.7sage.com/lesson/quiz-advanced-premise-conclusion-identification-1-answers/
#help. Answer choice A if negated does kill Trent's conclusion. If we assume that any asteroid that struck the earth struck land, not water, this would include the asteroid in question, rendering the crater in question not one created by an asteroid. Is A the wrong answer because we must accept that that crater was caused by an asteroid? Is Trent's first sentence a premise? I had thought it was one form or another of a conclusion. Thanks.