MBT - Conditional logic Question type

Comments

• 1 Like

  FixedDice Member

  April 2018 edited April 2018 1804 karma

  Either Perry’s faction or Tucker’s faction, but not both, will win. (P or T)
  If Perry’s wins, the nation will suffer economically. (P -> E)
  If Tucker’s wins, the nation will suffer militarily. (T -> M)

  In other words, either E or M is bound to occur. Notice that the scenario precludes neither (P -> M) nor (T -> E); only (P -> E) and (T -> M) are certain. If the scenario really wanted to preclude (P -> M) and (T -> E), it would have presented the last two sentence as biconditionals.

  Answer choices:

  (A): Wrong. Either P or T has to occur, which means E (economic suffering) or M (military suffering). There is no way the nation will not suffer.

  (B): Wrong. We are only given the necessary condition here. As mentioned above, (T -> E) is not precluded. So we don't know whether E resulted from P or T.

  (C): Wrong. The first part is right. But as mentioned above, neither (P -> M) nor (T -> E) are precluded, meaning (P -> E and M) or (T -> E and M) is entirely possible. So it is not "certain that [the nation] will not suffer both."

  (D): Correct. We are only given the necessary condition here. The stimulus indicates (T -> M), but as mentioned above (P -> M) too is possible. So from M, one can deduce that T may have occurred.

  (E): Wrong. The stimulus implies that P or T has to occur, which means that the second part of the answer choice is false.
• 1 Like

  keets993 Alum Member ⭐ ⏰ 🍌

  April 2018 6050 karma

  So if Perry wins then nation will suffer economically.
  PW -> NSE
  If Terry wins then nation will suffer militarially.
  TW -> NSM

  With ac A we don't know enough to support this. It's basically denying our conditionals. Because we know either Perry will win or Terry will win. And the answer choice is saying "possible not [NSE or NSM]" which I think might be the negation of the conditionals.

  Answer choice B states in lawgic NSE ->PW. That's classic invalid argument form. It's affirming the necessary and as a result concluding the sufficient condition.

  Answer choice C is tricky because it's asserting that PW or NSM will happen - which we can support 100% - but also claiming that it won't be both. We don't know that. It could be the case the Terry wins and the nation will suffer militarially but that effects the economy and so the nation suffers economically. It's the same with Perry. The nation suffering economically might cause the nation to suffer militarially as well because there might be less money to put into the military. We know it's either PW or TW and can't be both but the mistake is inferring that both NSE and NSM can't happen.

  Answer choice D states that if NSM then maybe, but not certain that TW. It's not the same as stating NSM -> TW because that's 100%. Whereas it's saying that if we affirm the necessary it's possible that the sufficient condition happened. Like logic games when you have a conditional and the necessary has been affirmed and so the rule becomes irrelevant and the sufficient condition is free to float. It could be the case that the sufficient condition has been satisfied or it could fail.

  And lastly, answer choice E is stating that if NSE and NSM -> /PW and /TW. Which is just condracticing what we've been told by the stimulus that one of them will win.

  Hope that helped!
• keets993 Alum Member ⭐ ⏰ 🍌

  April 2018 6050 karma

  @FixedDice I swear we're always typing at the same time
• 1 Like

  FixedDice Member

  April 2018 1804 karma

  @keets993 said:
  @FixedDice I swear we're always typing at the same time

  Great minds act alike!
• FixedDice Member

  April 2018 1804 karma

  Holy guacamole, this is a licensed GMAT question? Business school doesn't look as intimating and alien as it used to!
• akistotle Member ⭐ 🍌🍌

  April 2018 edited April 2018 9382 karma

  @FixedDice said:
  Holy guacamole, this is a licensed GMAT question? Business school doesn't look as intimating and alien as it used to!

  Sorry, the note had a mistake. It's from The Official LSAT Prepkit published by LSAC in 1990, and it seems like the book has been used for GMAT prep by many. (I don't know why. I guess it's usedful for GMAT's CR section?)

  Sorry @"Do the right way", any copyrighted content that infringe on copyright is prohibited on this Forum. (Copying and pasting something without a proper citation is plagiarism.) Please rephrase it like "Either A or B, but not both, will win...." and indicate where you found the question.
• keets993 Alum Member ⭐ ⏰ 🍌

  April 2018 6050 karma

  @akistotle
  I was browsing a GMAT prep book - a friend of mine was thinking about taking it - and their reading component is basically LR and RC. You got your MBT, weaken, strengthen question types for LR and entire passages for RC with the same questions that we get tested on.

  Holy guacamole, this is a licensed GMAT question? Business school doesn't look as intimating and alien as it used to!

  The daunting part for me is that on top of all that they gotta do math too. With formulas and all that other good stuff.
• Do the right way Alum Member

  April 2018 181 karma

  @akistotle Sorry about the infringement. I have rephrased the question. I hope this will do. And
  Thanks @keets993 and @FixedDice for your explanations. The explanations helped me. Thanks.