PT51.S4.G2 - LG#2 Help!

universeme

help

PT51 LG#2

Regarding rule #2,
/K and /L → J

I think the contrapositive of this should be,
1) L-J-K
2) K-J-L
3) J – K and L
= J-K and J-L

Why JY skipped 1) and 2)?
Did I miss something?

Admin Note: https://7sage.com/lsat_explanations/lsat-51-section-4-game-2/

phosita_phoeatah

It appears you are confusing instance of negation with contrapositive. Contrapositive is the rephrasing of a conditional in terms of negations (as in, P --> Q means the exact same as /Q --> /P), but contrapositive is not negation of the original statement.

Your item 3) is the correct parsing of the necessary part of the conditional statement of rule 2. Each of your 1) and 2) represents an instance when 3) is negated. E.g., J couldn't be more expensive than both K & L if item 1) were true. However, neither 1) nor 2) is the correct negation of the necessary part of the conditional statement of rule 2, which should read as follows:

((K - J) or (L - J)) --> (H - G)