June 2016 LSAT Section 2 Question 20

# Which one of the following could be the sixth audition?

1 Reply

Irina on December 16 at 05:09AM

@Ryan-Mahabir,Z cannot be #6 because it must take place earlier than Y per rule 4.

Please see below for the full setup:

The game requires us to determine the order of the auditions and whether they are recorded or not. The game involves six singers - K L T W Y Z. Two of their auditions are recorded - K & L and four not recorded - T W Y Z.

R

U

__ __ __ __ __ __

1 2 3 4 5 6

The following rules apply:

(1) The 4th audition cannot be recorded, the fifth must be.

This rule allows us to infer that the fifth audition must be either K or L, and 4th is neither K nor L.

R X

U X

__ __ __ __ K/L __

1 2 3 4 5 6

(2) W audition must take place earlier than two recorded auditions.

This rule tells us that W must audition before both K & L, thus W cannot be #6. and audition #1 cannot be recorded since W (unrecorded) must precede both recorded auditions.

W > K & L

(3) K audition must take place earlier than T audition.

This rule tells us that K cannot be #6, and allows us to infer that #5 and #6 auditions cannot both be recorded because it would leave no space for T.

Combined with the previous rule, another interesting inference is that W can only be #1 and #2 since we know that #4 and #6 are unrecorded auditions, the earliest the second recorded audition could be is #2 -K or L, hence we can infer that W must be #1 or #2, and K/L (second recorded audition) must be #2 or #3.

We can also infer that if K is #5, then T must be #6 and that T cannot be #1 or #2 because T must precede K and the earliest K could be is #2.

R X

U X X X

/K/L

/W /W /K/L __ K/L __

1 2 3 4 5 6

~T ~T ~K

~W

(4) Z audition must take place earlier than Y audition.

Z> Y

This rule allows us to infer that Z cannot be #6 and Y cannot be #1. Combined with the previous rules we can also infer that #1 must be either W or Z, and #6 must be T or Y.

R X

U X X X

/K/L

Z/W /W /K/L __ K/L T/Y

1 2 3 4 5 6

~T ~T

~Y ~Z

We can overall see that the only possible auditions that could take place sixth are either T or Y.