Sample LSAT Logic Game

Questions 1-5 An amusement park roller coaster includes five cars, numbered 1 through 5 from front to back. Each car accommodates up to two riders, seated side by side. Six people—Tom, Gwen, Laurie, Mark, Paul and Jack—are riding the coaster at the same time. Laurie is sharing a car. Mark is not sharing a car and is seated immediately behind an empty car. Tom is not sharing a car with either Gwen or Paul. Gwen is riding in either the third or fourth car.

GO TO Question 1 2 3 4 5 HOW TO SET UP THE GAME In attempting this logic game, perhaps you formed a series of pictures (either in your mind or on paper) of the riders in their respective cars as well as in relation to one another. Was the result a confusing mess? If so, don't worry—you have lot's of company! Let's start from scratch and establish a systematic 4-step approach. STEP 1 Determine your basic diagramming approach The initial premise and conditions allow for many possible seating arrangements. However, all of the possibilities fall into one of two alternative scenarios based upon the last condition (Gwen is riding in either the third or fourth car.). Accordingly, we can draw two distinct diagrams to represent these two scenarios: Scenario #1 (Gwen in third car): 1 2 3 G 4 5 Scenario #2 (Gwen in fourth car): 1 2 3 4 G 5 STEP 2 Allow your diagram to evolve as you consider specific rules Next, let's review the other conditions to determine what additional information, if any, we can include in our diagram. Consider the second condition: Mark is not sharing a car and is seated immediately behind an empty car. In scenario #1, either the first car is empty while Mark occupies the second car, or the fourth car is empty while Mark occupies the fifth car. In scenario #2, either the first car is empty while Mark occupies the second car, or the second car is empty while Mark occupies the third car. Accordingly, our initial diagram can be appended as follows (X indicates the empty car immediately ahead of Mark's car, and the bracketed "[M]" indicates that Mark is seated alone): Scenario #1 (Gwen in third car; Mark in second or fifth car): 1 X 2 [M] 3 G G 4 X 5 [M] Scenario #2 (Gwen in fourth car; Mark in second or third car): 1 X 2 [M] X 3 [M] 4 G G 5 STEP 3 Restate all rules in or around your diagram as pictures or symbols Next, consider the two remaining rules: Laurie is sharing a car. Tom is not sharing a car with either Gwen or Paul. If we try to include either of these conditions directly in our diagram, we would have to add several scenarios to account for all of the additional possibilities. What if we overlook a possibility? Run out of space on our paper? Run out of time? Instead of complicating our diagram, let's simply indicate the remaining two rules in symbolic or shorthand form to the side of the diagram for ready reference (the " ¬ " symbol indicates "not"): Scenario #1 1 X 2 [M] 3 G G 4 X 5 [M] [L _ ] Scenario #2 1 X T ¬ P/G 2 [M] X 3 [M] 4 G G 5 STEP 4 Ask yourself, "What else can I deduce?" Finally, let's ask ourselves what else we can deduce from the premise and conditions. In addition to Gwen and Mark, can we "fit" any other riders into our diagram? Well, we cannot determine from the initial premise and conditionswhere any of the other riders are seated. However, we can deduce that: one and only one car (the car immediately ahead of Mark's car) is empty exactly two cars are each shared by two riders exactly two cars (including Mark's car) are each occupied by one rider Why? The coaster could not accommodate all six riders otherwise (remember, each car can accommodate no more than two riders). This additional information is important in analyzing some of the questions. TIP: Always take the time to draw useful conclusions before you tackle the questions. Otherwise, you might waste time by repeating the same logical steps over and over as you analyze different questions.