147 comments

  • Wednesday, Feb 5, 2025

    #feedback I don't think it was emphasized enough in the previous lessons that the "Two Split Mosts" rule also applies to two "all" or "must" arrows. These two Skill Builders use this rule a lot, and I think it's tripping people up. I know I was confused at how you could get all these some relationships. This is how I see it:

    For example:

    A ‑m→ B

    A ‑m→ C

    You can validly conclude that B ←s→ C ("Two Split Mosts")

    But you can also do this:

    A → B

    A → C

    You can validly conclude that B ←s→ C (Because "All" or "Must" arrows are even stronger than "Most" arrows, 1 or more Bs must be Cs, and vice versa.)

    You can also use the contrapositive with this rule:

    B → A contrapositive /A → /B

    C → A contrapositive /A → /C

    You can validly conclude that /B ←s→ /C

    A rule of thumb is that the sufficient conditions must be the same in both relationships to validly infer a some relationship between the necessary conditions. If the necessary conditions are the same, you cannot infer a some relationship. You must take the contrapositive.

    43
    Saturday, Mar 15, 2025

    Extremely helpful. Thank you!

    0
    Wednesday, Feb 5, 2025

    you're a lifesaver

    0
    Sunday, May 24

    @camrynmartin7 agree. The key was that meeting the sufficient condition group.

    1
  • Thursday, May 22, 2025

    what the helly

    39
    Friday, May 23, 2025

    wthellybronjames fr?

    7
  • Wednesday, Jun 25, 2025

    I'm so confused...I really thought I got the hang of it but this skill builder ripped me a new one

    16
  • Friday, Dec 12, 2025

    How question 4 worked here.

    Commercial airline pilots are required to have the ability to perform the “Lazy Eight” maneuver.

    Most people who can perform the “Lazy Eight” maneuver enjoy flying.

    • Statement 1

      • Airline pilot -> The lazy 8

    • Statement 2

      • Lazy 8 -m-> Enjoy flying

    • Conclusion

      • No valid conclusion. But my mistake was that I thought this meant airline pilots liked to fly

    Why it is not valid

    • What we know is that ALL airline pilots can do the Lazy 8.

    • We also know that MOST people who can do the lazy 8 enjoy flying

    • This is invalid because we have no clue if the pilots who can do the lazy 8 are part of the people who enjoy flying. Nothing here is telling us that all of those pilots who can do the lazy 8 enjoy flying. For all we know each one of those hates flying because the lazy 8 gives them a stomach ache.

    Example to help understand:

    This is like me telling you

    • All of my friends are your friends,

    • Most of your friends are your brothers friends

    • SOOOOOO, does that mean my friends are now your brothers friends too?

      • NOPE. We have no clue here if my friends are also friends with your brother.

      • For all we know I could have only 1 friend, and that friend is with you, but you have 4 friends. The 3 friends who are not my friend could be friends with your bother. Hence, my one friend is not you brothers friend. Making it invalid to say that my friends are your brothers friends

    14
    Thursday, Aug 27

    @Student101 basically airline pilots does not equal the people mentioned in statement 2 correct?

    1
  • Friday, Dec 12, 2025

    4/5, question 4 tripped me up

    13
  • Friday, May 8

    Q4. I assumed that some pilots enjoy flying....

    12
  • Monday, May 11

    Q4 was the only one that really stumped me after finding out the answer

    11
  • Thursday, Aug 1, 2024

    This was a very frustrating and confusing unit, and there were no videos to help guide me in the right direction.

    11
  • Edited Tuesday, Jun 30

    Omg.. I was stuck on Q4 for at least 30 minutes trying to figure out why 「Commerical airline pilots - m -> enjoy flying」is wrong. And, just maybe, I cracked the code. This worked for me... kinda.

    So, let's use a different example to tackle this question.

    Premise 1: All students in Mr. ThisQuestionPissedMeOff's (Mr. TQPMO) class are on the school bus.

    Premise 2: Most people on the school bus have brown hair.

    • Can we validly make the argument that Most people in Mr. TQPMO's class have brown hair?

      • The answer is NO. Why?

    • Let's just say that there is only 10 students in Mr. TQPMO's class and there is around 50 students on the school bus.

      • We know that most of the students on the school bus have brown hair, so more than half of the students have brown hair.

      • 26 - Brown / 24 - Not Brown

    • Can we conclude that all of Mr. TQPMO's students have Brown Hair?

      • No! There is no way of knowing. For all we know, all 10 of Mr. TQPMO's students could have hair that's NOT brown.

    • I know this example is exactly like the one given, but I just couldn't figure it out for the longest time until I used a really easy example like this to finally understand the one given.

    10
    Tuesday, Jul 7

    @Min No, this was actually the perfect example. Before I read the entirety of it, I was talking it out loud and our explanations were the same.

    Thank you!

    1
    Tuesday, Jul 7

    @Min if you still want the explanation @marikitten03

    2
    Friday, Jul 17

    @Min this helped so much, thank you

    0
  • Saturday, Sep 13, 2025

    Daaaang question 4 got me! I can see why though. I confused sufficient for necessary with pilots and those who perform lazy 8. Dangit. 4/5.

    10
  • Friday, May 9, 2025

    I'm so confused I feel like crying in front of my computer screen. this is hard. Also, when. I was at the lessons that said to come back. I felt like the general understanding was that it was above our abilities, but this feels like I should understand it and I just don't, which is of course worse. I'm so lost. Didn't even get one right. Perhaps I Have to rewatch all these videos again. I am really having a hard time here.

    10
    Monday, May 19, 2025

    im really struggling too so youre not alone

    2
    Monday, May 26, 2025

    Me too bro

    2
  • Tuesday, Jul 16, 2024

    I'm very confused here, does anyone know of of videos online that can explain this to me?? #feedback

    10
  • Tuesday, Dec 19, 2023

    Is there a video explaining this concept? I am having some difficulty understanding it #help

    10
  • Thursday, Aug 15, 2024

    Im I the only one who didn’t understand?

    9
    Saturday, Aug 17, 2024

    I didn't either

    1
    Tuesday, Aug 20, 2024

    Once you do some LR, this makes sense

    0
    Wednesday, Aug 21, 2024

    that's what im hoping lol

    0
    Sunday, Sep 8, 2024

    #2 threw me off

    1
  • Monday, Apr 7, 2025

    this threw me for a loop

    8
  • Tuesday, Sep 10, 2024

    Im lost in this excercise, will have to read and repass until I get it. =/

    8
  • Thursday, May 28

    Why can't the right answer for Q4 be "some" persons who enjoy flying are commercial pilots

    Is it because commercial airline pilots and "people" are technically not in the same circle with lawgic?

    7
  • Wednesday, Apr 1

    tears of joy as i got most right when i was in the trenches in prior lessons but #5 did get me

    7
  • Wednesday, Oct 23, 2024

    Yeah.. it would have been better if question 5 was more written out.

    7
  • Thursday, Sep 26, 2024

    #feedback it would be helpful to include the translation of the question in the answer so we can double check our work

    7
  • Thursday, May 23, 2024

    can someone better explain this lesson i am lost

    7
  • Wednesday, Apr 9, 2025

    I am so. lost. Like I am not understanding this at all. Would it be worth it to just move ahead and come back later when I've gone through other lessons?

    6
    Sunday, Apr 13, 2025

    Yes! I felt the same way when I first started studying. It will make more sense when you are more exposed to the questions. There are plenty of times when I have revisited the fundamentals and things end up clicking after!

    3
    Friday, Apr 11, 2025

    ofc, let it marinate in your head and come back in a couple of days or less.

    0
    Friday, Apr 11, 2025

    me too.. i understood all of the earlier lessons but this one is so confusing to me??

    4
  • Saturday, Aug 10, 2024

    Can someone please validate my sentiment that, while I'm eventually grasping the concept(s,) this is realllly challenging :)

    6
    Friday, Aug 16, 2024

    Something that significantly helped me here is talking it out instead of exclusively focusing on chaining clauses or turning it into lawgic. Granted this set of questions was not super helpful in connecting a lot of the previous ideas for me; but at least for the last few examples that has been super helpful!

    0
  • Friday, Jul 12, 2024

    Nevermind.

    6
  • Thursday, Jun 27, 2024

    This has been the most challenging skill builder for me so far, what lessons or tips and tricks do people have to help understand this concept a bit more #feedback

    6

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