PT68.S4.G4 - an editor will edit seven articles (alternative approach)

namegoesherenamegoeshere Member
edited September 2016 in Logic Games 35 karma
https://7sage.com/lsat_explanations/lsat-68-section-4-game-4/
Hi, I'd like to share a method I used for pt68 game 4. At first glance, it seems like you have to brute force this game; however, you can solve it in a more efficient manner. With this method, this game took me a little under 9 min. Before starting this explanation, I will assume you understand the rules but let me know if you would like that explained as well.

The first step is to understand what the possibilities are in this game. It seems like anything could happen, but we are actually quite limited once we apply a few rules. One technique I found helpful in this game (and other similar ones) was to split via the Q3 rule. One with Q3 (therefore making the rule irrelevant) and one with Qnot3 (therefore triggering Q-S). By doing this, we no longer have to worry about whether or not to apply the conditional rule. Another thing I added towards my rules was that there must be something in between J and G (since they are both finance); the rule ended up looking like this J-X-G-R (just remember the X means "something"). This same concept can be applied to the Qnot3 rule; the result is Q-X-S-Y (the X here and the other X does not necessarily have to be the same thing, it's just there to represent the "something" that has to be there).

So let's start with the Q3 game board. With Q3, next we want to look at J; J has a minimum of 3 things after it so it would seem the only possible spots for J would be 1,2,4. It turns out 1 is not possible because there's nothing that can go in between J (1) and Q (3) other than Y, but Y has S before it. Therefore, we only have to look at J in 2 and 4. Whether J goes in 2 or 4, G and R must go after Q, otherwise we would violate the consecutive rule. If J is 2, we need something in 1 that is NOT finance. This means either S or Y, but not Y because of the S-Y rule. If J is in 4, G must be in 6 (can't put G next to J) and R must be in 7. To go in between J and G, we need something thats NOT finance. Again, this means S or y, but not S because of the S-Y rule again. This leaves us with S and H for 1/2 but since Q and S are of the same group, they must be separated by the H.

Gameboard 1.1 S J Q _ _ _ _ G-R, Y, H These 4 letters can go anywhere as long as they maintain the sequence required and the no consecutive rule. There's a few possibilities here, but it's really not that many nor is it complicated to see.
Gameboard 1.2 S H Q J Y G R (it's completely filled!!)

Next up is the seemingly complicated Qnot3 split. It ends up not being filled in at all, but we only have to remember 2 sequencing chains. As mentioned earlier, Qnot3 triggers our conditional rule leaving us with Q-X-S-Y. This sequence along with the previous J-X-G-R sequence is all we have to keep track of, and H. Once we place one letter, things will start to fall into place.
Gamebaord 2 _ _ _ _ _ _ _ [Qnot3] Q-X-S-Y J-X-G-R H(just dont put this next to G or J)

The questions go by pretty quickly.

I'll skip question 17.

Question 18. If Y is 4th... it is best to just look at one gameboard first to see what we can eliminate quickly. Let's put Y4 into 1.2. The result is S J Q Y G R H. B, C, E get eliminated. So we are left with A (J2) and D (Q3). The next board to look at is our only other possibility, which is 2. If Y is 4, then according to our sequence, we must have Q-X-S in 1,2,3 respectively. J can't 5,6,7 since there's 3 things after it so the only spot left for J is 2. The result is Q J S Y G R H. A (J2)

Question 19. If G is 4th, could be true, let's look at a board that has a lot filled in (ie 1.1) So S J Q G _ _ _ with R Y H to place. Scanning the answer choices quickly, you should see E (Y6). We can simply have S J Q G R Y H. E (Y6)

Question 20. Quick and easy, scan through the choices to see if we have anything filled in from our boards. B (H2)

Question 21. For this question we will have to do a bit of work, but nothing too hard since we only have simple rules to follow. If J is 3, we can only be looking at gameboard 2. _ _ J _ _ _ _ ... X-G-R will go to the right of J. What can go to the left of J? We can't put S on 2 because there's 2 things before it and we can't put Y on 2 because there's 3 things before it, so we're left with Q and H; H and J also can't go next to each other so we must have H Q J _ _ _ _ S-Y G-R . Since this is a could be true, the answer choice will most likely be one with S, Y, G, or R. That leaves us with A, D, E. G can't be 4th since J is 3rd [BYE A]. S can't be 2nd since Q is 2nd [BYE D]. Y 5th is ok ... H Q J S Y G R E (Y5)

Question 22. S could be what except...check your previous work!! S1 is in 18. S3 is in 18. S4 is in 21. We don't have anything for S5 or 6, but that's ok because now we only have to test 1. I would choose S6 because that will force Y7. _ _ _ _ _ S Y (this will be gameboard 2 so just fill it in using our remaining sequence chains) We can have J Q G R H S Y. S6 works so our answer will be D (5)

Question 23. To do this question most efficiently, you'll have remember our earlier rules about sequences. If we put R4, that forces J-X-G into 1,2,3 respectively thus placing us in gameboard 2. J _ G R _ _ _ Q-X-S-Y H The only thing that can go in between J and G is Q and H, but not H since it's finance (along with J and G) therefore.. J Q G R _ _ _ S-Y H R and S are both nutrition therefore we are forced into this result J Q G R H S Y C(R4)

Comments

  • inactiveinactive Alum Member
    12637 karma
    Edited title and contents to abide by forum rules and for spacing purposes so people can read it better. Thanks for sharing!
  • dtodaizzledtodaizzle Alum Member
    58 karma
    I did the same thing; I split up my boards up according to the Q3 rule. In addition, I have also written subscripts to designate which ones are F,N, & W.
  • noynek29noynek29 Alum Member
    12 karma

    Thank you for this great solution. Practicing this game really helps sharpen a few different skills at the same time.

  • youbbyunyoubbyun Alum Member
    1755 karma

    this game was really tough.

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