Hi @slew. It's because this is not an either/or sentence. It's not "either marketplaces or agorae." It's "marketplaces, otherwise known as agorae." Hope that helps!
Jashieon January 7, 2018
Also, how come the sentence, "the cities' agorae were centrally located and goods were traded there either for money or for commodities." is not diagrammed as an either/or sentence?
Mehranon January 13, 2018
Good question. It has to do with the syntax of the sentence. In this case, the either/or does not operate to set up a disjunction. Put another way, the sentence does not establish that "money or commodities" are alternative sufficient or necessary conditions.
Hope this helps! Please let us know if you have any additional questions.
Denzeljones14on June 1, 2018
for example #1 I don't understand how you got your answer? it has white flowers but lacks fuzzy seedpods. Need better explanations please
Denzeljones14on June 1, 2018
The way you're setting up these examples with the s & N and contrapositive is confusing me for some reason
Christopheron June 6, 2018
There are multiple layers of logic here that you must keep in mind to be able to answer the question.
First, Fuzzy Seeds always have Long Stems and never have White Flowers. Or diagrammed: FS ==> LS & not WF. The contrapositive of which is: WF or Not LS ==> not FS. So if a plant has white flowers or does not have a short stem, it cannot have Fuzzy Seeds.
Second, Curled Leaves always have White Flowers: CL ==> WF. Contrapositive: Not WF ==> Not CL.
Thirdly, Thorny Seedpods always have Curled Leaves: TS ==> CL. Contrapositive: Not CL ==> Not TS.
Finally, you're given the FACTS that Plant X has a Long Stem and Curled Leaves.
So looking at the rules that mention Curled Leaves, we know that Curled Leaves must have White Flowers (Rule 2). We also know that they CAN have Thorny Seedpods (Rule 3). Thorny Seedpods require Curled Leaves, but the opposite is not true.
Rule 1 deals with Long Stems by saying that they Fuzzy Seeds require a Long Stem but no White Flowers. Since the plant has Curled Leaves and therefore White Flowers, we can conclude that plant X cannot have Fuzzy Seeds.
It may or may not have Thorny Seedpods, but we can't know that with the information given, so (A) and (B) are out.
It must have White Flowers, so (E) is out.
It cannot have Fuzzy Seeds, and there is not enough information to know about Thorny Seedpods, so (D) is out.
Leaving (C) which accurately concludes that the plant must have White Flowers (based on rule 2) and cannot have Fuzzy Seeds (based on rule 1).
Hope that helps.
biancabreborjason June 13, 2018
This is just a general question by the way, so nothing specific when it comes to a particular question.
As I get further along through the course (I am watching the videos, and working more from the book by the way, then online). But it is obvious that sufficient and necessary terms are used a lot. My question is, my setups for these types of questions are taking me so long, that I know timing is going to kill me. Is there any way that I don't have to do the whole set up, but still get the correct answer? It seems like it is almost impossible to do so many setups basically for every question. Or is it a obvious answer like it will come as I get more practice?
Thanks!
Christopheron June 15, 2018
Writing out the setup each time is good for practice, but some of these questions will get obvious enough with time that you won't need to write them out. By the time I got to my final attempt at the LSAT, I only wrote out a few full setups on the harder questions, as I'd gotten to the point that a lot of questions were obvious. It's a good drill, and you should be able to write them out for each question, but by the time you're comfortable with the test, you're not going to need to write out each part on every question.
Denzeljones14on June 19, 2018
I am having problems with the missing drills flashcards. on some of them I get correct but for the most part I don't really understand how the set up is suppose to go. Is there a better way for me to understand or do I need to watch the video again?
Christopheron June 21, 2018
Reviewing the video can help, but practicing real questions can help a lot too. For me, at least, too much time on flash cards made it harder for me to understand the practical side and not just the theoretical. It takes practicing both.
pfdellapoon July 28, 2018
I'm really having trouble with the missing premise questions. Can someone help me?
KristenShawon August 17, 2018
I also don't understand missing premise. I watched the video but I don't even understand where that was explained in the video.
Denzeljones14on August 23, 2018
Okay so I took the sufficient and Necessary questions and I didn't do so well. For most of these questions it was sections that I haven't reviewed yet like flaw questions, pattern, must not be true, and must be true. I understand why I got some of the questions wrong except for (Flaw and pattern) but how do I apply S&N towards it because it would seem like a lot of time to diagram out every single passage and question. Especially on the flaw pattern of reasoning questions.
Mehranon August 24, 2018
Hey there. As explained throughout the thread above, practice is key here. You are right that, especially at first, diagramming S&N questions will take a lot of time. But this is why successful LSAT students spend some time doing untimed practice to develop and quicken core skills (like diagramming). Over time, you will not only be able to accurately diagram more quickly, but you will likely also find that you don't need to diagram except on the hardest questions. At first, however, it's very important to spend the time and practice accurate diagramming, without worrying too much about how long it's taking you. Practice will help you get faster while maintaining accuracy. Hope this helps! Best of luck.
Tonyon September 29, 2018
Hi there. In example 2, how come you dont diagram the contrapositives for answer choice: BCDE, like you do for option A.
lefon October 23, 2018
test
ScottPalmeron December 27, 2018
For Example Question #4, although it is irrelevant to the answer choices, why does the last sentence not introduce a S/N condition? (Either for goods or commodities)... For future reference.... thanks in advance.
Ravion December 27, 2018
@melissakaijukags,
Great question.
Answer A contains the exact same contrapositive argument structure that we see in the stimulus. From this, we know that this answer choice is our answer.
In the video, Mehran does not walk through the others likely because we have already found an answer with an identical argument structure the one in the stimulus. For the remaining answer choices, we don't necessarily need to write out the contrapositives to see that their argument structures do not match the argument structure in the stimulus.
When you're taking the test, it is a good practice to write out the contrapositives of arguments to give you greater clarity for answering questions. However, once you have identified an answer choice that matches exactly what you're looking for, you don't want to spend too much time confirming that the other answers are wrong, as this can eat up precious time that might be more useful for you on challenging questions in the section that require more time for you to answer.
Does this help? Let us know if you have more questions!
@lef,
Did you have a question? All I'm seeing in your message is the word "test." Let us know if there's something we can help you with on this problem!
@the person who asked about example question #4,
The last sentence introduces facts that are intended to distract you from the inference of
MS - >MP /MP - >/MS /MP /MS
The last sentence tells us that Greek cities' marketplaces were centrally located and that goods were traded there for either money or for commodities.
In this sentence, there is no wording that denotes sufficient and necessary conditions. The types of words to look out for are words like all, any, every, if, the only, only, when, whenever, must, only if, then, requires, etc.
The aforementioned terms, and all terms that describe sufficient and necessary language, are strongly worded and do not provide room for exceptions. We're told that the Greek cities' agorae were centrally located, but were ALL of the Greek cities' agorae centrally located? We do not know. Additionally, We're told that goods were traded there either for money or for commodities, but were ALL goods there traded for either money or for commodities? We do not know. In other words, we do not know if there were any exceptions.
Technically, if we assumed that all of the Greek cities' agorae were centrally located, we could write
Greek city agorae - ->centrally located agorae /centrally located agorae - >/Greek city agorae
and if we assumed that all goods at the Greek marketplaces were traded for either money or for commodities, we could write
Greek city marketplace goods - ->traded for money or traded for commodities /traded for money and /traded for commodities - >/Greek city marketplace goods
However, note that we'd be making assumptions here since there is no conditional language in the sentence. As a result, since there is no conditional language, we do not write out sufficient and necessary conditions with this last sentence.
Does this help? Let us know if you have more questions!
sigmajonez14on May 29, 2019
also have a question in general about the sufficient and necessary methods, if we see if the question does not have any sufficient or necessary words does that mean we go to see if there are in quantifier words and if none of those would we go to the weaken or strenghtn method
or
step 1 argument or facts
step 2premise principle conclusion
step 3 sufficient necessary or quantifier
step 4 method of stem and eliminate answers
sigmajonez14on May 29, 2019
@ravi
@mehran
Ravion May 30, 2019
@sigmajonez14,
Great question. You should always be on the lookout for words that indicate sufficient and necessary conditions, as well as words that are quantifiers, but you're thinking about things too mechanically. That strategy won't always work, so stick the strategies that are discussed in the video lessons.
Hope this helps. Let us know if you have any other questions!
sigmajonez14on May 30, 2019
im still getting stuck on the conclusion part versus the answer choices, whether to make it into a sufficient equation and then to make the premise into a one also then to compare it against the answers , very lost
Ravion May 31, 2019
@sigmajonez14, It sounds like you might be thinking about the test too mechanically. Focus on reading the stimulus and concentrate on what it's saying. Most times, you don't need to diagram, but diagramming can help while you're familiarizing yourself with certain concepts. Also, this stuff takes time to learn, so continue to review the curriculum and video lessons (and revisit them a second or third time, as it will help to reinforce concepts).
sigmajonez14on June 3, 2019
okay still having trouble with breaking down the stimulus and irrelevant answers and
are we trying to weaken or strengthen the sufficient part of the conclusion
Ravion June 3, 2019
@sigmajonez14, when you say "the sufficient part of the conclusion," I'm not understanding what you're referring to, as there isn't a sufficient part of a conclusion. In strengthen and weaken questions, you're either strengthening or weakening the argument, which is the relationship between the premises and the conclusion.
sigmajonez14on June 4, 2019
Or as to the part of the conclusion that must be weakened or strengthen by the answer choice
Such as this question
Most nutritionist recommended eating fish twice a week. Eating tilapia fillets is a perfect choice for those who want the benefits of eating fish but do not care about the taste of fish. Tiliaplia fillets lack the strong fishy taste that many people find objectionable.
If true most seriously weakens the advertisements arguement?
A. Eating more than the recommended amount of fish can cause toxins that are present in high concentrations in many varieties of fish to accumulate in a persons body
B. Tilipia are invasive species that crowd our native species of fish in lakes throughout the world
C. Tilapia fillets contain little of the beneficial fish oils that are the main reason nutritionist recommend by most nutritionist
D. Most people who do not care for the taste of fish eat less than is recommended by most nutritionist
E people who rarely or never eat fish usually dislike any food with a strong fishy taste
Preptest 81-83
I would look at the conclusion from the stimulus
Conclusion- most nutritionist recommend eating fish twice a week
Then go against the answer choices that either strengthens or irrelevant
I would choose d ?
Ravion June 4, 2019
@sigmajonez14,
For the question you provided, you did not correctly identify the conclusion. The conclusion is that eating tilapia fillets is a perfect choice for those who want the benefits of eating fish but do not care for the taste of fish.
The sentence you cited as the conclusion is actually one of the argument's premises. The other premise is the last sentence, which states that tilapia fillets lack the strong fishy taste that many people find objectionable.
The argument is basically trying to convince us that eating tilapia will provide someone with the benefits of eating fish without the bad fish taste. We know that tilapia fillets lack the very fishy taste that lots of people like and we also know that nutritionists recommend eating fish twice per week.
We're trying to weaken this argument. One key thing to note is that the argument states that we can get the benefits (nutrition) without the negative (bad taste) by eating tilapia fillets. How can we weaken this? Well, one way would be to provide evidence that states that one can't have the nutritious benefits without the bad taste (the nutrition and the bad taste are tied together). There could be other ways, too.
You picked (D). (D) says, "Most people who do not care for the taste of fish eat less fish than is recommended by most nutritionists."
We're looking to weaken the argument, and that's best done by finding evidence about tilapia that makes it less likely to be healthy or less likely to be tasty or have a non-fishy taste. (D) has nothing to do with tilapia, and it doesn't weaken the argument.
(C) says, "Tilapia fillets contain little of the beneficial fish oils that are the main reason nutritionists recommend eating fish frequently."
(C) is a great, as it tells us that the tilapia fillets have very little of the good fish oils that are the main reason that nutritionists recommend eating fish often. So, even if the fillets don't have a really fishy taste, (C) tells us that someone is not likely to get the same health benefits by eating tilapia vs. eating another type of fish that tastes really fishy. (C) weakens the argument, so it's the correct answer choice.
Hope this helps. Let us know if you have any more questions!
sigmajonez14on June 7, 2019
how would I know if something is a principle
Victoriaon June 8, 2019
Hi @sigmajonez14
Generally, questions that are asking you about a principle will use the word ' principle' in the question stem. This identifies right away that you should be looking for a principle somewhere in the passage.
A principle is a general rule which serves to guide behaviour or reasoning. These statements are generally quite broad and suggest a rule which should be followed when faced with a certain scenario or dilemma.
Hope this is helpful! Let us know if you need anymore clarification or tips!
Tonyon February 9, 2021
Hi Test Max team, for the question re: democracy functioning well -> electorate is moral & intelligent, can you explain more in detail why C is correct? I guessed it right based on POE, but what kinda threw me off was that it says "not moral & intelligent." I was expecting to see "not moral OR intelligent." Wouldn't the AND make it something different? I know you only need one of them to be sufficient, it's just not super clear from the way the author wrote the sentence.
Victoriaon May 7, 2021
Hi there,
Happy to help!
You are correct that the contrapositive of the statement is "if the electorate is not moral or not intelligent, then the democracy will not function well."
I agree that the way the answer choice is written is confusing. As it is a bit ambiguous, I think the answer choice could be read in two ways, either of which would still make it the correct answer choice.
Option 1 - the author intends the "not" to encompass both moral and intelligent
"If the electorate is not moral and not intelligent, then a democracy will not function well."
We know that if the electorate is not moral OR if the electorate is not intelligent, then a democracy will not function well. This answer choice is correct because we know that the electorate does not meet either of these conditions; therefore, the democracy cannot function well.
Option 2 - the electorate is not moral, but the electorate is intelligent
This interpretation is still correct because we know that the electorate only needs to be not moral OR not intelligent for the democracy to not function well.
Hope this helps! Please let us know if you have any further questions.
Anokhion June 3, 2022
How can you just switch the "And" to an "Or" for question number 5, without reversing and negating for option C. I don't understand the getting of the answer.
rizzguyon August 24 at 10:48PM
At 2:10ish - Letter C is the correct answer. Why is that correct even though the answer choice does not properly reverse and negate the logic? Stimulus says "electorate IS moral AND intellegent" as the necessary condition. Answer choice C says "electorate IS NOT moral AND intellegent" not OR as the sufficient. The fact that it wasn't "or" was why I didn't chose that answer.
Emil-Kunkinon August 25 at 07:37PM
The passage tells us that two things are necessary. The electorate must be both moral and intelligent. Therefore if the electorate fails to be moral or fails to be intelligent, or both, then democracy will not function. When there are multiple necessary conditions the failure of any one of them or all of them will serve to mean that the sufficient cannot happen.
rizzguyon August 25 at 09:32PM
Got it! Thank you. That made sense to me after 45 minutes of staring haha
Emil-Kunkinon August 26 at 04:35PM
Great! I'm a huge fan of thinking of things in the common sense, real world approach as a supplement to your diagram. It's pretty hard to see the formal logic rules of why this is right, but in plain English I find it makes way more sense.
rizzguyon August 26 at 05:57PM
Certainly. Thanks so much!
Could you explain the missing premise drills breifly? I'm not sure what they are asking us to do, as I can come up with versions of the correct answers that say the same thing, like contrapositives and such. But I find these drills particularly abstract.
A good example of one that confused me is as follows:
Question:
P: A --> not B
P: ??
-----------
C: B --> C
My answer with written out contrapositives:
P: A --> not B
B ---> not A
P: A --> not C
C --> not A
--------------
C: B --> C
not C --> not B
Correct answer with written out contrapositives:
P: A --> not B
B --> not A
P: not A --> C
not C --> A
---------------
C: B --> C
not C --> not B
I don't understand how that second premise is different. Why does it have to be Not A --> C and Not C --> A opposed to A --> not C and C --> not A? How are those two different?
Emil-Kunkinon September 3 at 09:13PM
In general these drills mirror sufficient assumption questions, and I agree I find them tough specifically because they are very abstract- much more so than the actual sufficient assumption questions.
In general we want to find a way to link the existing premise to the conclusion in a way that is logically valid.
Let's look at your example here. I'm going to make the drill a little more concrete. At first we are told that if one is an apple, it cannot be blue. That is, if it is an apple it is not blue. We are then trying to prove that if something is blue then it is clean. How can we do this?
Well we know that there are no blue apples, so if something is blue, it is not an apple. So, we need to show that if something is not an apple then it must be clean. That is, if not A then C. This gives us the chain that
B then Not A then C.
It seems like part of your question is the difference between
If A then Not C And If Not A then C.
These mean completely different things. The former means that A and C are mutually exclusive. It means that there is no overlap between A and C- one can be at most one of those two things.
The latter means that one must be at least one of those two things. That is, if something is not an apple it is clean and visa verse. This means that everything in the world is at least one of those attributes.
Let's try plugging the latter in our chain: If B then not A, if A then not C.
This doesn't prove that if B then C. The premises don't like up anymore.
