@ShahmeerRaza yes I do! What I've come to realize is that understanding the entire scope of why all wrong answer choices are wrong is arguably more important than just getting the question right, which the videos really help to develop.

B is really well explained in the video!

I picked it E and it was a classis part to whole flaw

Just because one part of the production (expense of dyeing is avoided) is cheaper does not mean the entire product (finished garment) is cheaper.

Just because the green and brown cotton do not need to be dyed does not mean that green and brown cotton are less expensive to manufacture than regular cotton- it can have all sorts of additional costs related to growing these g &b cotton like harvesting, spinning, weaving etc. which can add to the cost of the finished product.

@LiaWang I think that's when you look at B's wording with future tense "Once...will". The scope of the stem is only constricted to the present not what will happen. It never goes to mention what should happen in the future. That's why B also does not hold up through a primary lens.

I tried doing an experiment-

I skimmed the stem and then tried to guesstimate which one could be the answer choice. I was looking for something that had a looser wording and, lo an behold, it was A. Wording for all the other answer choices were too extreme: future tense, the only etc.

Got so lucky! yey

@VanceKatzfey I think you just need to skim the answer choices a bit to see if parsing the correct answer requires a logic chain or not.

@emlit343 There's simply no way to answer this quickly without doing the chain

@heron2078 I think once you see "If dt traffic congestion" in A,C and D you would know that there is no arrow generating from it and can immediately mark it off as wrong.

Similar thing with E, the prompt is "profit increase" and not "profit", so to negate profit increase can include profit remaining constant, not profit decrease. The stem just does not give us any info for a case where the profit decreases.

@charlie.jin Honestly just go through the fundamentals section for conditionals. That would help a lot!

@kbblommaert968 Simply put, I think if negating something breaks the entire argument then that has to be true for the argument. That MUST BE TRUE for the argument to be valid.

Yey 5/5 so happy, even though I couldn't tell why some of the answer choices were wrong. Just sounded like they would be wrong!

@matthewd52 The way I think of it is:

what you said about B is technically an addition to Meli's point. Sam does not get to contribute a second time.

Its almost like: Sam: X

Meli: no X, but Y

Y here is (B), Sam. Technically Sam does not get to disagree with what Meli says; it's Meli who disagrees with what Sam says.

I hope this helps!

This was a wordy question ...

@bernardjoon1261 C is essentially:

Certain (some) human concerns and interests arise in all of the world's cultures = Some human concerns and interests are common in all of the world's cultures.

Pretty loosely tied so right answer

@raceanu91591 When we paraphrase C:

"Some" human concerns and interests arise in all of the world's cultures = Some human concerns and interests are common in all of the world's cultures.

If we don't consider these statements as true, I don't think you can conclude that from the stimulus that comparative studies from widely separated epochs and diverse cultures have common themes.

Essentially its talking about a commonality across all cultures regardless of time.

@Lsatslayer At least one also set off an alarm for me too! That was also the reason I picked C in the beginning because it is vague enough to be strongly supported by the conclusion.

@BenPocheron Hey, the way I see it is:

The context lays out that there is a disproportion between text and music and then goes on to saying which side is shorter. "These texts are generally quite short=music are longer disproportionately. so we can say that it is explicitly stated.

Between text vs. music the premise states that there's just more music and not that much variation of texts. Imagine the same lyric just getting repeated over and over again with different music notes so that people can just focus on the music. You only need so many repetitions of a single sentence to make people understand. Repeating the same lyrics only helps people to focus on the musical aspect of the song.

@ToweringTextbooks I think I understand what you're getting at. I find this to be very similar to the "some can include all" rule too. The sentence "Some apples are red" will allow for both the outcomes of:

a. Only one apple being red

b. All apples being red

Having all apples as red does not change "some apples" to "all apples" it just means that "all apples" satisfies the "some apples" condition.

Given the number of comments I read on people being confused between contrapositive and negation, merits an individual video lesson on it.

@leahlovescoco To add to that:

Saying "some" actually makes an existence claim, meaning that at least one of it exist but could be more. To negate that would be saying that none exist at all.

@ConqueringLSAT

Contrapositive:

If cat, then mammal

C->M

/M->/C

If not mammal, then not cat

This is the exact same sentence as: If cat, then mammal. Contrapositive is another way of saying the same things but with nots & nones.

Negation:

If cat, then not mammal

You destroy the subset superset relationship by taking out the subset out of the superset i.e. take out the cat from being a mammal.

Original statement: In order for it to be a cat, it must be a mammal.

Negated statement: In order for it to be a cat, it does not require to be a mammal. It is a cat and not a mammal.

C and /M

1.      SOME DOGS ARE FRIENDLY

At least one dog is friendly

Not all dogs are not friendly

 Negate: No dog is friendly

All dogs are not friendly.

 2.      ALL DOGS ARE FRIENDLY: 100% dogs->F

 Negate: It’s not the case that all dogs are friendly.

Not all dogs are friendly: >100% dogs->F

Some dogs are not friendly

@krzhou_1 The difference between many and some is that it makes an existence claim, not a percentage claim unlike the difference between many vs. most. If X is many, that means that X exists (at least one of X exists)= X is some

@KindlyQualifiedChampionship

some means at least one can be all or not, but has to be at least one. So, we need to attack what we know must be 100% true for negation. To negate (opposite) this you need to at none.

Some pets are dogs.

Negation: No pets are dogs.

Contrapositives keeps the meaning same by slapping negation to both sides of the sufficient necessary clauses, but keeps the meaning same. Lets try it with this example:

Some pets, then dogs.

P←s→D

Contrapositive: /P←s→/D

Some non-pets are not dogs. Does this mean the same thing as some pets are dogs? NO, it completely changes its meaning.

I was confused at first but I think I know why some can include all:

Some students pass the LSAT only if they study everyday.

In order for the necessary condition to be true it has to include at least 1 student, but can also include all students, that is, even if we say all students have to study everyday for passing LSAT, does not fail the necessary condition. So it can include all!

Essentially we need to look for anything can cause the necessary condition to fail and exclude that interpretation.