5 Ways to Solve Logic Games in Under 7 Minutes

LSAT Blog Days Week DiagramThese tips and tricks will show you how to beat each Logic Game in less than seven minutes. Think it can't be done? Think again!


1. Create a diagram.

LSAT course instructors sometimes tell you to create a grid for every game instead of using a basic slot diagram. A slot diagram is an easy way to draw the information contained in linear and combination games (games that contain linear AND grouping elements). Grids take too long to draw, but making one slot for every letter takes less time (in a 5-person/thing diagram, it is similar to: _ _ _ _ _ ).


2. Re-use diagrams you made in previous questions.

They'll often help you quickly answer the rest of the game's questions. Haven't realized this? Try it out. Make a new diagram for every "if" question you come across, unless one of your previous diagrams satisfies the "if." Use the space at the bottom of your booklet to make your main diagram. Also use this space to map out the deductions you make from the game's rules. Many games let you use old diagrams to answer one of the later questions. If you notice this, you'll save time because you won't have to make a new sketch.


3. Whenever you see an "If" question, make a diagram BEFORE looking at any answer choice.

When you see something like: "If X is placed in the second position, which one of the following could be true?" or "If Z is first, it must be true that..." My students know to stop reading immediately after they see the comma and to draw whatever must happen when that "if" happens. This basic drawing is often enough to solve the question. You don't even have to draw a diagram for each answer choice, which saves you a lot of time.


4. In "acceptability" questions, take each rule and apply it individually to all 5 answer choices.

Most games begin with a question like, "Which of the following is an acceptable assignment / ordering / grouping..." All of the choices except one will represent unacceptable orderings because they violate at least one rule.

The slow way to eliminate choices is to apply each rule to a single choice and then move on to the next one.

The faster way is to pick a single rule and apply it to each answer choice. In other words, take one rule at a time and apply to to all 5 choices. If a rule says A is always before B, check to make sure that each answer choice satisfies this rule. Eliminate each choice that violates the rule. Then take the next rule and check it against the remaining choices to make sure they satisfy this rule.

Try each method, and I'm certain you'll find the latter way to be more efficient.


5. When the rules severely limit the possible scenarios, sketch each one.

Take the second game in the June 2002 LSAT (PrepTest 37). The game asks you to put 7 trucks in order. Sounds like a pain, but the good news is that after you place the last 4 trucks in order, the potential outcomes for the first 3 spaces become very limited. You're left with trucks U, X, and Z after you map out spaces 4-7. Because Z has to go before U does, the possibilities are limited to "Z U X", "X Z U" or "Z X U". The alternative method is to only draw one of these possibilities, and if you don't get your answer, you could draw another one. This alternative approach frustrates many students because they often pick the wrong scenario on their first try.

For this reason, it's more efficient to draw the elements of a game that "must be true" and then consider which possibilities are valid. I suggest that you try each potential scenario immediately and then proceed to answer each question in the game. In short: make all your diagrams first, then read each answer choice one-by-one. This will help you solve each game more quickly.

Photo by caroslines CC BY-NC-SA 2.0



6 comments:

  1. very good suggestions! it's always a little confusing to understand what the heck the game requires, but it's definitely easier to figure it out if you set yourself up with a diagram first.

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  2. Great advice, thanks!

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  3. Hi Steve, I found your explanation on the Birds in the Forest - PrepTest 33, Game 2 Problem VERY useful. Do you have similar explanations for other types of LG problems?

    Thanks!

    Hernan

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  4. How can you tell when the rules limit possible scenarios? Are you supposed to infer this?

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  5. good advice. I knew that I was doing something right. thanks for the tips on the other types of games senarios because I was banging my head up against the wall with the "if" and "which" type of questions.

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  6. Can you please comment on exactly why it's important to quickly identify a game's type? By "type" I am referring not only a specification of a game's major category (linear/grouping/sequencing etc.), but also specifications of all sub-types - e.g. defined/undefined, balanced/overloaded/underfunded and the like.

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