June 2002 LSAT Section 3 Question 19

# Which one of the following could be an accurate list of the swimmers of the first five laps, in order from lap 1 thro...

Replies

Ben on December 10, 2019

Hi DDL, thanks for the question.I will look into the video explanation for you, but for now I will hopefully provide some help through here!

This game presents us with 5 variables: J, K, L, M, O

Each variable is placed twice and we know the following: 1 and 6 are the same, 2 and 7 are the same, 3 and 8 are the same, 4 and 9 are the same, and finally, 5 and 10 are the same.

So in essence, we just need some way to remind ourselves that 1-5 and 6-10 are the exact same order. Perhaps putting a line through the middle of 5 and 6 could work, as follows:

__ __ __ __ __ I __ __ __ __ __

1 2 3 4 5 6 7 8 9 10

Additionally, we can draw the two sets (1-5 and 6-10) stacked.

__ __ __ __ __

1 2 3 4 5

__ __ __ __ __

6 7 8 9 10

Or, if you feel more comfortable noting everything out explicitly, you may write in your rules:

1 = 6

2 = 7

3 = 8

4 = 9

5 = 10

Now for the rules:

KL in a crossed out block. This also means that we cannot have if K is in 5, then L cannot be in 1, because L would also be in 6 and this violates the rule.

J does not go in 9 (by extension, not in 4 as well)

M - O, simple sequencing rule. This means that M cannot go 5th nor 10th, and O cannot go 1st nor 6th.

At least one block of OJ. It might appear that we would always place OJ in a block if one pair is already in such a placement. Consider if we put O and J in 2 and 3 respectively. Then it would __ O J __ __ I __ O J __ __

1 2 3 4 5 6 7 8 9 10

However, the at least one in this rule allows for the following possibility.

J __ __ __ O I J __ __ __ O

1 2 3 4 5 6 7 8 9 10

Please let me know if this was helpful as far as setup goes. And let me know if you have any other questions!

Dustin on December 10, 2019

Thank you!Ravi on January 14, 2020

@DDL, let us know if you have any other questions!on September 6, 2020

Is there a video explanation or link that can direct us to a video explanation?