@jaidaanderson I think you're confusing necessary for sufficient condition. You might have an action that benefits another and is performed with that intention, but might not be morally good. Also don't forget to apply De Morgan's law and flip the AND to and OR.
For Q5, I translated 21 or older as 21+, but then I thought "in the US" is another condition, so my Lawgic formula was:
21+ and in-the-US --> can-purchase-alcohol
or /can-purchase-alcohol --> /21+ or /in-the-US
Is this incorrect because I'm drawing outside inferences, or why wouldn't being in the US also be a required condition to purchase alcohol? If you're not in the US but still 21+, you still might not be able to purchase alcohol, no?
I realise now that it's because the question assumes 21+ --> (legally allowed to purchase alcohol in the US), where in the US, it is part of the necessary condition of being legal, not something separable from being legally allowed.
Hey, quick question about this sentence: "All self-driving cars must be programmed to ensure not only the safety of its passengers but of other people on the road as well."
Why isn't "must be programmed" part of the sufficient condition, similar to how "after a week" is part of the sufficient condition in "Anyone infected by the virus will, after a week, produce antibodies"? Shouldn't it be: self-driving cars + programmed → ensure safety?
@lydiaaaaaa I think it's just describing the action being committed to make the necessary true. I think of it as just an elongated part of the "then" because it is describing what must be true about the subject
@Daniel.p3raza i don't think the wording of the lawgic needs to be as it is written in the lesson verbatim; as long as you get the idea and get the variables right, that means you are understanding and are doing them right!
@DamianoVigneri I think of the "all" indicator as placing one circle inside the other. In order for everyone who is 21+ to be able to purchase alcohol, the 21+ circle must be inside the 'can purchase alcohol' circle. It doesn't work in reverse. If the 21+ is the superset, then only a subset of this population would be in the 'can purchase alcohol' bubble.
Three seems to be withholding another element. I thought that it would be inf -> produce antibodies and fight. The purpose clause would be analogous to the "with..." clause in question two. I see my mistake, that in the sufficient condition, I should have included after a week, but if we care about including all elements of consequence, then shouldn't we also include the purpose clause? I feel that we haven't covered such a situation and there is an active disregarding of my problem. Am I mistaken, or is there a good reason the purpose clause is not included?
@Hfa Because both necessary conditions have to be met for the sufficient condition. The way they are independent is this: If the sufficient condition is met we can say, one (or both) of the necessary conditions are met. So, If an action is morally good, we can safely say it benefits others, without necessarily saying that it was performed with that intention. However, it certainly was.
Does anyone understand what he means when he says that /eligible -> /IW or /501C doesn’t mean that it has to be one and not the other? Or also when he says that it could mean “neither”. I think I need that a bit more clarified. Pls help lol!
Can someone explain why the virus and the 1 week after, are togther the sufficient clause? I thought the 1 week would be a necessary condition along with the antibody.
@JuliannaCalder the appositive "after a week" is a modifier of the noun anyone infected by the virus. With those two conditions met, infected and a week, then we get antibodies.
Think of a similar situation: a tennis player. Anyone participating in Wimbledon, after reaching the semifinals, will receive prize money. The two conditions we have to meet to "receive prize money" is both "Participating in Wimbledon and reach semi-finals." I usually like to change the appositive to "and". So rather than the commas, I just think to myself: If you're participating in Wimbledon and reach the semifinals, then you will receive prize money.
Participate + Semifinals-> Prize Money.
This is the same structure as the one you are asking about. Let me know if this helps
@cristiangarpec no because after is generally a modifier, or more loosely a sufficient indicator. If you say "after [X], then [Y]", that means that when [X] happens, then [Y]. For example, after I take the lsat, I will apply for law school.
LSAT->Law School
Now that doesn't mean that the LSAT is necessary, which is true with JDnext, it is just triggering the necessary condition.
Sometimes it helps to just put it in your own words
i already know my biggest weakness is gonna be confusing sufficiency for necessity when there are no indicators... does anyone have any advice or ways i can do more lessons on this?
@NoraElkhyati Something that helps me is grouping the concepts into the subset and superset (sufficient and necessary, respectively). For instance, for question 2, I identified trees as a subset to the supersets perennial plants and plants with stems; trees fit these two criterion, but there are other perennial plants and plants with elongated stems that are not trees, thus making trees the subset (sufficient) and per./e-stem the superset (necessary). This would therefore translate to, with the use of de Morgan's for the contrapositive:
T -> per. and e-stem; contrapositive of /per. or /e-stem -> /T.
If you approach the sentence, "All cats are mammals and are adorable," you could identify that mammals and adorable are two supersets; there are other things that fit into these categories other than cats. However, cats also fit into these two as a subset. Therefore, cat must be the sufficient condition and mammals and adorable must be the necessary conditions. This comes out to:
C -> M and A; contrapositive of /M or /A -> /C.
I hope this makes sense and is of any assistance to you guys! Best of luck on the LSAT, you got this!!
@NoraElkhyati always thing about set and super set. also helps to think that sufficient (set) guarantees something to happen. But the necessary condition(super set) does not guarantee. example if it is raining, then the ground is wet.
you see the rains is sufficient and guarantee that the ground is wet but the ground being wet is not guarantee that it is raining. Could be wet for any other reason.
For #6, I also had pet adoption center in my sufficient condition. But in the logic they just have website and 501(c)3 non-profit. That doesn't make sense to me because it could be an organization to help veterans.. if it has just a website and it's 501(c)3 that doesn't mean it can be eligible for the Mittens Grant. I think pet adoption center needs to be in the sufficient condition.
@Laylay Hi Laylay, you would be correct if the question stated "Only pet adoption centres with..." rather then what we got which was "If a pet adoption centre", meaning the stimuli has informed us what it is, so we must operate under the understanding that this information is static.
Or in other words, it seems you may be more focused on the modifiers.
So if you are infected with the virus and if one week has passed then you produce antibodies. So both having virus and after 1 week means it’s necessary to have antibodies
Contrapositive is= if you don’t produce antibodies, then you either don’t have the virus or it hasn’t been more than a week?
I think I’m confusing this because now the contrapositive to me sounds like it’s only necessary to have a virus (no matter how long) or a virus for a week or more long to develop the antibodies.
I guess my question is how do I interpret the contrapositive and connect back to original without changing the meaning the “or” makes me think now only 1 is necessary but in the first it’s like antibodies are necessary when you have both virus after a week. Hope I’m explaining my thoughts right.
Subscribe to unlock everything that 7Sage has to offer.
Hold on there, stranger! You need a free account for that.
We love that you want to get going. Just create a free account below—it only takes a minute—and then you can continue!
Hold on there, stranger! You need a free account for that.
We love that you came here to read all the amazing posts from our 300,000+ members. They all have accounts too! Just create a free account below—it only takes a minute—and then you’re free to discuss anything!
Hold on there, stranger! You need a free account for that.
We love that you want to give us feedback! Just create a free account below—it only takes a minute—and then you’re free to vote on this!
Hold on there, you need to slow down.
We love that you want post in our discussion forum! Just come back in a bit to post again!
Sorry, you need a subscription for that.
Happens all the time: now that you've had a taste of the lessons, you just can't stop -- and you don't have to! Click the button.
257 comments
Didn't get all of them right but I understand the explanation. A win is a win!🤷🏽♀️
I always write these backwards. What am I missing?
Benefits another person AND performed with that intention > action is morally good
/(action is morally good) > /benefits another person AND /performed with that intention
Also can someone explain what I did wrong in Q5.?
Anyone who is twenty-one years old or older is legally allowed to purchase alcohol in the United States.
21+ > legally allowed to purchase alcohol + United States
@jaidaanderson I think you're confusing necessary for sufficient condition. You might have an action that benefits another and is performed with that intention, but might not be morally good. Also don't forget to apply De Morgan's law and flip the AND to and OR.
For Q5, I translated 21 or older as 21+, but then I thought "in the US" is another condition, so my Lawgic formula was:
21+ and in-the-US --> can-purchase-alcohol
or /can-purchase-alcohol --> /21+ or /in-the-US
Is this incorrect because I'm drawing outside inferences, or why wouldn't being in the US also be a required condition to purchase alcohol? If you're not in the US but still 21+, you still might not be able to purchase alcohol, no?
I realise now that it's because the question assumes 21+ --> (legally allowed to purchase alcohol in the US), where in the US, it is part of the necessary condition of being legal, not something separable from being legally allowed.
Hey, quick question about this sentence: "All self-driving cars must be programmed to ensure not only the safety of its passengers but of other people on the road as well."
Why isn't "must be programmed" part of the sufficient condition, similar to how "after a week" is part of the sufficient condition in "Anyone infected by the virus will, after a week, produce antibodies"? Shouldn't it be: self-driving cars + programmed → ensure safety?
@lydiaaaaaa I think it's just describing the action being committed to make the necessary true. I think of it as just an elongated part of the "then" because it is describing what must be true about the subject
6/6 i feel so much better about this
Question, does it have to be exact? For the last one I wrote it like this
IW And 501 -> Mittens
/Mittens -> /IW or /501
@Daniel.p3raza i don't think the wording of the lawgic needs to be as it is written in the lesson verbatim; as long as you get the idea and get the variables right, that means you are understanding and are doing them right!
For Question 5, why is 21+ not the necessity? Why is allowed to purchase? Doesn’t allowed to purchase depend on and necessary to be 21+?
@DamianoVigneri I think of the "all" indicator as placing one circle inside the other. In order for everyone who is 21+ to be able to purchase alcohol, the 21+ circle must be inside the 'can purchase alcohol' circle. It doesn't work in reverse. If the 21+ is the superset, then only a subset of this population would be in the 'can purchase alcohol' bubble.
Three seems to be withholding another element. I thought that it would be inf -> produce antibodies and fight. The purpose clause would be analogous to the "with..." clause in question two. I see my mistake, that in the sufficient condition, I should have included after a week, but if we care about including all elements of consequence, then shouldn't we also include the purpose clause? I feel that we haven't covered such a situation and there is an active disregarding of my problem. Am I mistaken, or is there a good reason the purpose clause is not included?
Six questions. Scandalous.
For conjunction within necessary condtion, didn't it say that the two actions/conditions are independant of each other?
If yes, then why in question #1, it says that both benefiting others and intention should be met for an action to be considered morally good?
I'm so confused :|
@Hfa Because both necessary conditions have to be met for the sufficient condition. The way they are independent is this: If the sufficient condition is met we can say, one (or both) of the necessary conditions are met. So, If an action is morally good, we can safely say it benefits others, without necessarily saying that it was performed with that intention. However, it certainly was.
@BMago I see now. Thank you for the clarification!!
Pretty simple!!!
Does anyone understand what he means when he says that /eligible -> /IW or /501C doesn’t mean that it has to be one and not the other? Or also when he says that it could mean “neither”. I think I need that a bit more clarified. Pls help lol!
@Valleygirlala I think he means that if an adoption center is not eligible, it could mean any one of three things:
it does not have an interactive website (/IW)
it is not a 501c (/501c)
it does not have either a website and is not a 501c (/IW and /501c)
He is merely reminding us that option 3 is also possible, which is that an ineligible adoption center could lack both a website and not be a 501c.
#3 was initially not intuitive whatsoever to me
Is it necessary to do the contrapositive each time?
@CaleighFreeman The exercise suggests you do for sake of practice. You don't need to do it on test day.
I really like the explanation of question #6
Can someone explain why the virus and the 1 week after, are togther the sufficient clause? I thought the 1 week would be a necessary condition along with the antibody.
@JuliannaCalder the appositive "after a week" is a modifier of the noun anyone infected by the virus. With those two conditions met, infected and a week, then we get antibodies.
Think of a similar situation: a tennis player. Anyone participating in Wimbledon, after reaching the semifinals, will receive prize money. The two conditions we have to meet to "receive prize money" is both "Participating in Wimbledon and reach semi-finals." I usually like to change the appositive to "and". So rather than the commas, I just think to myself: If you're participating in Wimbledon and reach the semifinals, then you will receive prize money.
Participate + Semifinals-> Prize Money.
This is the same structure as the one you are asking about. Let me know if this helps
@joegav1 Thank you so much! That makes a lot more sense. I appreciate it!!!
@joegav1 this was very helpful, thank you!
@joegav1 Could "after a week" not be used as a modifier for the predicate, "produce antibodies...the virus"?
@cristiangarpec no because after is generally a modifier, or more loosely a sufficient indicator. If you say "after [X], then [Y]", that means that when [X] happens, then [Y]. For example, after I take the lsat, I will apply for law school.
LSAT->Law School
Now that doesn't mean that the LSAT is necessary, which is true with JDnext, it is just triggering the necessary condition.
Sometimes it helps to just put it in your own words
back here after 8 months of studying.... this stuff is important I promise!!
i already know my biggest weakness is gonna be confusing sufficiency for necessity when there are no indicators... does anyone have any advice or ways i can do more lessons on this?
@NoraElkhyati This is also my biggest problem, it is confusing sufficiency for necessity
@NoraElkhyati Something that helps me is grouping the concepts into the subset and superset (sufficient and necessary, respectively). For instance, for question 2, I identified trees as a subset to the supersets perennial plants and plants with stems; trees fit these two criterion, but there are other perennial plants and plants with elongated stems that are not trees, thus making trees the subset (sufficient) and per./e-stem the superset (necessary). This would therefore translate to, with the use of de Morgan's for the contrapositive:
T -> per. and e-stem; contrapositive of /per. or /e-stem -> /T.
If you approach the sentence, "All cats are mammals and are adorable," you could identify that mammals and adorable are two supersets; there are other things that fit into these categories other than cats. However, cats also fit into these two as a subset. Therefore, cat must be the sufficient condition and mammals and adorable must be the necessary conditions. This comes out to:
C -> M and A; contrapositive of /M or /A -> /C.
I hope this makes sense and is of any assistance to you guys! Best of luck on the LSAT, you got this!!
@NoraElkhyati always thing about set and super set. also helps to think that sufficient (set) guarantees something to happen. But the necessary condition(super set) does not guarantee. example if it is raining, then the ground is wet.
you see the rains is sufficient and guarantee that the ground is wet but the ground being wet is not guarantee that it is raining. Could be wet for any other reason.
Hope this help
For number 8, if we don’t diagram the last sentence what kind of answer choices would we be looking for as an example?
For #6, I also had pet adoption center in my sufficient condition. But in the logic they just have website and 501(c)3 non-profit. That doesn't make sense to me because it could be an organization to help veterans.. if it has just a website and it's 501(c)3 that doesn't mean it can be eligible for the Mittens Grant. I think pet adoption center needs to be in the sufficient condition.
What I had:
pet adoption and website and 501(c)3 -> eligible
@Laylay Hi Laylay, you would be correct if the question stated "Only pet adoption centres with..." rather then what we got which was "If a pet adoption centre", meaning the stimuli has informed us what it is, so we must operate under the understanding that this information is static.
Or in other words, it seems you may be more focused on the modifiers.
Are these the only practice problems for this?
I def fell for the red herring bs.
is the voice different?
5/5, im on a roll
Just to clarify for question 3:
So if you are infected with the virus and if one week has passed then you produce antibodies. So both having virus and after 1 week means it’s necessary to have antibodies
Contrapositive is= if you don’t produce antibodies, then you either don’t have the virus or it hasn’t been more than a week?
I think I’m confusing this because now the contrapositive to me sounds like it’s only necessary to have a virus (no matter how long) or a virus for a week or more long to develop the antibodies.
I guess my question is how do I interpret the contrapositive and connect back to original without changing the meaning the “or” makes me think now only 1 is necessary but in the first it’s like antibodies are necessary when you have both virus after a week. Hope I’m explaining my thoughts right.