PT77.S4.Q20 - selena claims to have psychic powers

lampars2lampars2 Free Trial Member
edited February 2016 in Logical Reasoning 11 karma
Hello 7sagers, does anyone have any idea how to get the correct answer of question 20 of the second section of logical reasoning from dec 15 lsat? Trying to diagram out the conditionals and am struggling. My tutor couldn't even figure out this question.... JY Ping?? Advice from a logical expert would be greatly appreciated as this question is haunting my dreams!!

Comments

  • inactiveinactive Alum Member
    12637 karma
    PT 77's explanations are for sale right now if you want to pick them up:
    https://7sage.com/addons/

    Are you sure it's question 20? That question isn't about Selena's psychic powers.
    https://7sage.com/lsat_explanations/lsat-77-section-2-question-20/
  • inactiveinactive Alum Member
    edited February 2016 12637 karma
    I think you may be talking about Section four and not section two. S4 has the psychic power question:
    https://7sage.com/lsat_explanations/lsat-77-section-4-question-20

    Edited title to reflect that!
  • lizmiss24lizmiss24 Alum Member
    edited February 2016 50 karma
    I got stuck on this question too! :( I've watched JY's explanation and I'm still stuck - why wouldn't (A) be the correct answer here? I chose (A) because I thought that, if someone else were already shown to have psychic powers, then we wouldn't need to rely on Selena to determine whether psychic powers were possible. I guess that this is a necessary assumption?
  • inactiveinactive Alum Member
    12637 karma
    @quinnxzhang typed up a great explanation from this thread that I think you guys should check out!
  • jeff.wongkachijeff.wongkachi Member
    410 karma
    Not JY, but here's my explanation of it...

    I think the main reason Answer Choice A is wrong is because in order to get to AC A, you must automatically assume AC B.

    Essentially, just because no one has been found to have psychic powers yet, does it follow that it becomes possible to find out whether or not psychic powers are possible? Unless you assume already that Selena does actually have psychic powers, how does it lead to the conclusion that we can prove the possibility of the existence of psychic powers? We don't know whether or not Selena actually has them! Even if she doesn't, it's not like that means we can determine whether or not it's possible to have psychic powers. There could be other people that actually have them! This is too open ended.

    AC B is more effective because adding this AC to the stimulus makes it so that the conclusion MUST be true. If it's the case that having psychic powers is indeed a possibility and that Selena does in fact have these powers, then it must be the case that if we can determine the truthfulness of Selena's claim, we can thereby conclude the existence of psychic powers.

    Does this make sense?

    In a more general sense, I think the key take-away from this question is properly identifying the gap from the premises to the conclusion in order to generate a strong prephrase by (in this type of question at least) filling up the hole.
Sign In or Register to comment.