Hey-hey. The statement in the stimulus doesn't say "Danaxil stops pain more quickly than other pills". It says "no pill stops pain more quickly". Say there were 10 runners in a mile long race. Joe and Mike both crossed the finish line at the exact same time (4 mins, 0 secs). They tied for first place. We can say "No runner ran more quickly than Joe". We're not denying Mike the tie by saying that. It's also true to say "No runner ran more quickly than Mike". That's the same verbal shenanigan they're playing here. We know that all other competitors ≤ Danaxil, not that all other competitors < Danaxil. Let me know if that doesn't make sense.

I feel that I have to agree with you on this as well. I read the response below, but it still doesn't make sense to me. I understand the verbal shenanigan in the runner example, but correlating it to the question in the video doesn't add up. "No pill stops pain more quickly" = no competitor stops pain more quickly. I would also have gone with choice B on this one. The whole explanation about the 20min reference I would see as assumptions. Going off by the advertisement, it does not state anything to imply a competitor can relieve headaches at the same time as Danaxil. I want to believe the answer is C, but i'm not grasping it lol..

@@tvitasthe advertisement states “No headache pill stops pain more quickly.” Never does it say Danaxil is quicker than any other pill, that is a false assumption. The advertisement only guarantees nobody else will be quicker. The original comment was blatantly incorrect in restating the passage, and contradicted themself towards the end. Despite that, their

Hey Ravi, there sure is. Context matters. No cause and no effect would strengthen a conclusion that put forward a causal relationship. It would not prove the relationship, but it would make it more likely to be true. In this case, we're talking about a conditional relationship and we're on a Must Be True question. In the latter, we need to find something that must be true. In the former case, we're looking to add support to the conclusion. So you have two big differences. Your task is different (Must Be True vs. Strengthen) and the reasoning structure is different (Conditional Logic vs. Causation).

@@LSATLab I apologize for asking this, and I appreciate your response immensely. However at 19:21, the video states this question falls under the causation reasoning structure based Must Be True questions. Based on your guidance in the Conditional Reasoning video, I completely agree that if this Must Be True question utilized conditional logic, it would not be permissible to do a forward negation. However, this question uses a causal chain with causation based reasoning as indicated by the language. Thus, is there a difference between what must be true in a causal chain and what can be added to strengthen a causation-based conclusion (no cause, no effect)?

It's fucked up!

Indeed😂

We do have a video called "Causation" and a video called "Conditional Logic". "Causation" is much more likely to help you with GMAT CR, since Assumption / Strengthen / Weaken / Evaluate questions often feature an author concluding a possible explanation for a curious fact (and GMAT primarily likes to test alternate explanations). Conditional Logic isn't really going to help you on GMAT. It essentially never shows up. There will be an occasional Inference (aka Draw a Conclusion) question that will involve a rule, which *could* be expressed conditionally, but you're never chaining conditionals together or dealing with particularly tricky conditional trigger wording. So you'd be fine handling that rare Inference question without ever diagramming a conditional statement.

@@LSATLab Really appreciate the feedback, also the videos are one of the best prep videos that are out there, very organized and methodological, are you guys also tutor for GMAT? If so, what's the contact? Thanks! I master GMAT RC by stating with LSAT RC, I kept going on with LSAT until I hit 90% RC accuracy, now I don't usually get any RC wrong unless they are 4 or 5 difficulty, at which level my accuracy ranges from 50-70% max, so I thought I would start with LSAT for CR as well to build a base. I am reading Ellen Cassidy's The Loophole in LSAT, it's an user friendly book but I found some of the concept are counterintuitive, I also have PowerScore GMAT CR, which I plan to read next, do you think following your video playlist will help? If so, what are the ones I should focus on, I am not sure which ones are in particularly tested more frequent in GMAT, in comparison to LSAT, Sorry for such a big reply, appreciate you making these videos available to public, helps general students who cannot afford quality material or tutor, thanks again!

@@Bossanik , we aren't a GMAT company yet, but we will probably expand in a year or so to other test types. The useful for GMAT videos would be any of the Reading Comp videos (right now there are just big picture reading videos up, and those are relatively the same as GMAT reading advice ... the forthcoming videos that break down question types will all be applicable). For CR, you might wanna do Strengthen, Weaken, Evaluate, Assumption, Paradox (Explain Discrepancy), Comparisons, Causality, and Most Supported. Role might help a bit (for those boldface questions), but LSAT gets more into argument terminology than GMAT. I haven't read Loophole, but I've heard good things about it. There will definitely be a lot of stuff in there that isn't super relevant to GMAT CR (famous flaw stuff like Part vs. Whole, Nec vs. Suff, Circular, etc. is not relevant). And stuff relating to conditional logic is not relevant. Also Parallel Reasoning questions are incredibly rare on GMAT. But I think/hope she teaches a rebuttal style of analyzing arguments ... something like, "GIVEN this evidence, HOW CAN I STILL AVOID BELIEVING the conclusion (or how can I argue the opposite of the conclusion" That mentality is definitely worth rehearsing for CR arguments.

@@LSATLab Thanks a lot once again for taking the time, looking forward to the RC videos!

There aren't any "Could Be True" questions in Logical Reasoning (you might be thinking of Logic Games, where those are common). On *Must Be False* questions in Logical Reasoning, the four wrong answers each could be true, but we don't actually have a way to prove something could be true. We just consider that it could be true if it's not contradicted by the statements.

Great observation! It's not quite a contradiction, but there is the potential FOR a contradiction. If M were out, a contradiction would ensue. So one of the things you can infer from those three rules is that M must be in. (I'm using in/out as a proxy for yes/no, but same difference) Another way to think of the same thing is that the last rule looks like this: ~ K --> L ~L --> K That guarantees that at least one of L and K is in. They can't both be out, because either one being out would force the other one in. So since we know that at least one of L and K is in, we know that the trigger of the first rule is going to happen no matter what, and thus we know that M will be IN no matter what.

Yep. That makes sense. Thanks!

Thank you for the videos! They are very helpful :)

Yes, you're correct at the end there. Think of it in terms of the sufficient and necessary conditions - if there is sewage (sufficient), then there is algae (necessary). Contrapositive being if there is not algae (sufficient), then there is not sewage (necessary). What answer choice D does is negate without fully committing to the contrapositive (flipping the sufficient and necessary when making a negation) - this being if not sewage (sufficient), then not algae (necessary). Do you see the error there compared to the correct contrapositive above? In plain English terms, there's nothing in the stimulus that says sewage is the *ONLY* cause of algae in the estuary, but that sewage *WILL* cause algae if present. There could be other factors that cause algae without sewage present, there might not be - it's just not stated. I think you could argue that D is incorrect also because it's unsupported by the stimulus. The LSAT is very rigorous with the language used and what words specifically mean. Unfortunately, those meanings are often different than what our colloquial understanding is. I hope this helped out!

Hey, I'm not sure I understand your question. When there is an "or" in the trigger, then either trigger idea is enough on its own to guarantee the outcome. For example: "If I watch a sad movie or if I read about climate change, I get sad". We could separate those into two rules, if we wanted to: "watch sad movie --> sad" and "read about climate change --> sad" So the rule, "If K or L, then M" could be broken up into K --> M and L ---> M Whenever K is true, M is true. Whenever L is true, M is true. If K and L both happen to be true, M is true. If there were an "and" in the trigger, then you can't split them up into their own rules. For example, if the rule said "If K and L, then M" then knowing that K is true wouldn't be enough to tell us that M is true. We would still need to know whether L is true before we could guarantee that M is true. Is that what you were asking about?

Which part of the video are you asking about? Choice (C) on which of the questions? Are you talking about the one with coffee prices?

@@LSATLab Yes 🥺

@@Mayelinida No, C isn't a reversal. You might be getting confused based on the fact that the "if" is placed deep into the sentence, rather than at the beginning. There's no difference between saying "if X happens, Y happens" and saying "Y happens if X happens" Both of them would be diagrammed X --> Y Wherever in a sentence the "if-condition" appears doesn't matter; it belongs on the left side of the arrow. (C) said, "The shop's profitability will decrease if the price of beans increases", so that would look like "Price of beans increase --> profitability decrease" And as Matt walks through there, we know that 1. if price of beans increase, then shop's prices will increase. 2. if shop's prices increase, then they'll start selling noncoffee stuff or sell less coffee" 3. in either case, that leads to decreasing profitability (we are separately told that selling noncoffee leads to decreased profitability, and told that selling less coffee also leads to decreased profitability). So it's true that if the price of beans increase, then the profitability will decrease, as (C) says. Let me know if any of that was confusing.

More coming as quickly as possible :)

We really need more , so helpful

@@LSATLab thanks please do

Hey, are you appearing for LSAT 2020?

One day, I'm sure we will. Thank you for the suggestion Ridhima!