anyone can give me suggestions on doing the 'sufficient' type of questions. I cannot even understand the basic. Which views should I go through again?? So hard!!

how can i memorize these details? it is so challenging!!!

I still do not understand why C is redundant while D is not...

I still do not understand how to approach to this kind of questions. Does the correct answer usually fill a logic gap of the statement? A paraphrase of some information (causal mechanism?)? or something else??

I am thinking between B and E. I think E denies the premise. Isn't it? Most right choice does not deny the premise. isn't it??? Am I wrong again??? so sad :(

I think answer B is irrelevant. It does not answer the question and say nothing about the sunscreen. so, is this enough to prove that sunscreen might not be s'''t? how to deal with irrelevant answers. Shall we compare the irrlevant answer to other choices before choosing it??/ thanks

It takes me three minutes to draw the LAWGIC and figure out the answer.... I do not think I have enough time to do that in the exam. However, I cannot do the question without drawing the arrow. This particularly one is not intuitive.

how to see the results of the drills I took after I closed that window? I do not want to create a new drill...

How to see my results of the drill again???/?

Hi, I would like to hear some examples about some effects are not correlations...I think it is very tricky that 'correlations' denotes the idea of 'simultaneity' and 'concurrency'

Haha, I agree. From a philosophical point of view, there may be not something occurs before something, given the order, i.e, the time, is an illusion. The cause and effect are one concurrently. There is no past nor future but 'NOW'.

I think your contrapositive is correct.

so, is the Harry Poter example valid? I think it is. The use of 'probably' indicates that Draco Malfoy might or might not be Harry Poter's friend.

All dogs are friendly.

My understanding of negation:

negation: 'none of dogs are friendly' or 'at least one dog is not friendly' or 'some dogs are not friendly'. There is the possibility that 0% to 99% dogs are not friendly.

It seems that 'some dogs are not friendly' implies that 'all dogs are not friendly, because 'some' can imply 'all'.

Correct me if I am wrong!

I will score 170 +

I will score 170 +

I will score 170 +

I still do not understand what 'domain' actually means

wait, I think the video is very helpful!!

Can we think the modifier as another 'and' statement, i.e, 'and' condition.

for instance:

"Any journalism that provides accurate information on a subject about which there is considerable interest is good journalism."

Accurate-information and interest -> good journalism

/good journalism -> /accurate-information or /interest

(is it okay to think this way?)

Or we still think that 'interest' is part of the modifier to modify the condition of 'Accurate-information' and hence cannot be regarded as another condition.

Exactly, the logic chain is that A and B and C and D->E. You need to state that A, B, C,D altogether lead to the result of E (with the arrow "->"). (In this case, E is the conlusion and A, B, C, D are the premises necessary to make the E happen). However, simply saying that A and B and C and D does not clearly show their relationship with E. You need to say first that A, B, C,D contribute to E. So, if A, B, C,D are all present, then E is the conclusion/ or E is satisfied.

Anyone please correct me

Question four confuses me. "Some people claim that any internally consistent scientific theory is plausible."

I think "plausible" is the superset while "any scientific theory" is the subset. The sentence should be translated into "If something is plausible, it could be ineternally consistent scientific theory. but any internally consistent scientific theory must subject to the 'plausible'. I still think it is the 'plausible' makes the scientific theory necessary.

Therefore, I believe "plausible->internally scientific theory". it is not the right answer. Please correct me.

https://www.khanacademy.org/test-prep/lsat-prep/xdf35b2883be7178a:lsat-prep-lessons/xdf35b2883be7178a:lsat-prep-logic-toolbox/a/logic-toolbox--if-and-only-if

I found this link from Khan Academy might be helpful, even though I am still struggling.

I am still very confusing. Let's take this example. I will go to a park if it's sunny. (let's not use 'only if' first)

So, 'Sunny' is the superset, while 'go to a park' is the subset. However, the sunny weather does not restrict me from going to other places. If it's sunny, I can also go to a soccer field. the sunny weather does not make me have to be at park. But everytime I am at a park, it is sunny. Am I correct??

Ok, then we change it to 'I will go to a park only if it's sunny'

So, 'go to a park' is the superset, while 'sunny' is the subset? I am really confusing...... Do I make mistakes on distinguishing between the premise and conclusion?

As English is not my first language, I find logic very difficult to understand. Please helppppppp. thanks

But what if we changed the bar example into 'you can go to a bar if you are over 21' (instead using 'only if') (or, is it wrong to rewrite in this way?)

Does it make 'go to a bar' sufficient? Emily is over 23. She is over 21, so she can go to a bar. But she can also go to places other than bar such as a nightclub, a court or some dangrous places with age limit. Being 21 is necessary for Emily to go to a bar but she does not have too go to a bar and hence she has other options.

Then we go back to the example: ' you can go to a bar only if you are over 21'

Emily can go to a bar. She must be over 21. But going to bar does not necessary make her to be over 21???????? I think I am still very confusing. Do I still make mistakes on differentiating the premise from conlcusion?????

If an argument is valid, it means the argument is logically correct (The premise supports the conclusion and does not contradict one another.) Even though the premises are false, it can still be a valid argument.

It is necessary to be in superset first then and to be in the subset

The Eiffel tower is not in the USA. So, it must not be in NYC.

Being in the subset is enough to be in the superset (Empire state is in NYC and of course it is in USA)

But it is not necessary to be in the subset to be in the superset (Even though grand canyon is not in NYC, but it is in the USA. It is not necessary for everything in NYC to be in the USA.