What a great explanation, thanks!

Have you gone through the core curriculum yet or is all that you have done so far the 3 prep tests?

#help

Could someone please explain to me Question 3. I am putting down as my answer:

1wk & antibodies -> infected

With the contra positive of:

/infected -> /1wk OR /antibodies

This logic makes sense to me in English:

If it has been 1 week and your body is producing antibodies then you are infected.

Compared to the provided answer

infected and 1wk → antibodies

if you are infected and it has been 1 week then your body is producing antibodies.

These both look like logically sound statements to me.

Am I missing something? Usually after seeing the correct answer I can see the way I am supposed to interpret these sorts of questions but this one I'm having a hard time with.

Because they are not linked. Lets see if maybe translating it to English helps you better grasp it:

If I buy a car, then I now have to start getting gas and windshield washer fluid.

The fact that I have to get gas and windshield washer fluid are a result of me getting a car and are in no way tied to one another. I don't have to get gas just as a result of me getting windshield washer fluid.

The two necessary conditions are a result of one sufficient condition and can even be broken down into two diagrams if that maybe helps illustrate this concept better:

Lets take the example you asked about "M, N, O":

M → N and O can be represented as:

M -> N

M -> O

This is because we know that if we have M we will have N and we also know that if we have M we will also have O.

As I write this I think maybe one of the reasons you might be getting confused is because of the other example given in this lesson:

A and J → CF

This cannot be broken down to:

A -> CF

J -> CF

But that is because in this example we are saying (in an english example):

I need a hammer and a screwdriver to fix this car.

Just having one either a hammer or screwdriver are not sufficient for fixing the car.

I hope this helped and if I missed the mark then hopefully someone else can explain it better!

Thank you!

Thank you!

7.1-7.5 Make no sense to me. What exactly are we trying to obtain from them? It is a departure from the rest of the questions which asked for a translation to english & contrapositive after breaking down the sentence. So far it seems like its a primer for the future lessons but im not sure if this is the right way to look at it. #help

If that link doesnt work, which for some reason it isnt when I try pasting it just google: 3.2: Necessary and Sufficient Conditions Libretexts

I would recommend doing worksheets for necessary and sufficient to drill this area. I found a few that were good by doing a google search, just make sure to find one that contains the answers.

This is the one I used: https://batch.libretexts.org/print/url=https://human.libretexts.org/Bookshelves/Philosophy/Critical_Reasoning%3A_A_User%27s_Manual_(SouthworthandSwoyer)/03%3AConditionalsandConditionalArguments/3.02%3A_Necessary_and_Sufficient_Conditions.pdf

I'm going to get a 170 on the June LSAT :smile: