Free Sample LSAT Logic Game

I didn't write the following blog post. It was already on the blog when I took over the URL. The following blog post may contain mistakes. -Steve

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The following is a sample Analytical Reasoning (Logic Games) question. Be sure to leave comments if you'd like clarification, have another way to solve it, etc.

In a week, a man buys exactly six goods...greens, ham, keel, liver, pastrami, and sausage. Two are bought on Monday, 2 on Tuesday, and the last 2 on Wednesday, under these conditions:

The liver is bought on the same day as the pastrami.

The greens are not bought on the same day as the ham.

If the keel is bought on Monday, the greens are bought on Tuesday.

If the sausage is bought on Wednesday, the ham is bought on Tuesday.

If the ham is bought on the day before the sausage, then which one of the following CANNOT be true?

A) The ham is bought on Monday.

B) The keel is bought on Monday.

C) The greens are bought on Tuesday.

D) The pastrami is bought on Tuesday.

E) The pastrami is bought on Wednesday.

Solution

The first step on Analytical Reasoning questions is getting a system of symbols to represent the possibilities in the game. Unless you're Einstein, and maybe not even then, you are going to need some kind of diagram to answer at least some of the questions in every game. Since the first letters of all of the foods the man bought are all different, just go with G H K L R P S.

Next, you need a diagram to show the different relations (in this case, what items were bought on what days). The same kind of diagram works for just about every kind of LSAT game, fortunately:

Monday | Tuesday | Wednesday


So, we know have three columns. (This is kind of hard to draw in a blog...just imagine the lines extending downward in a table.) Put the symbols into each of them to show the day on which each item was bought. Given what the question told us, we know (the arrow just means "bought before"):

H --> S

So let's fill in the table with that information, and see what happens. By trial and error, we find out that this arrangement obeys all the rules above (they have the Roman numerals in front of them...one the real test they will not, but here I included the numerals to make it easier to read and refer back to)

Monday | Tuesday | Wednesday

H K | S G | L P

Now, we need to go through all the answer choices and just mark off the incorrect ones.

A) Our diagram says H is on Monday, so this is wrong. It obviously can be there, since we did it.

B) Diagram says K is on Monday, so this is wrong.

C) Diagram says G is on Tuesday.

D) Correct.

E) Diagram says P is on Wednesday.

Sometimes, the diagram won't answer eliminate 4 answer choices at first, but only a few, and you'll have several possible answers. In that instance, just retool the diagram using trial and error to make it accord with the rules and eliminate 4 answer choices. Here, we eliminated 4 on the first try, leaving us with one correct answer.

Remember:

1) Symbols are needed for each of the quantities (in this case, the food items bought). Use the first letter of the name of the item...the LSAT writers never seem to make two quantities with the same first letter, in all the tests I've seen.

2) A diagram is needed to show where the quantities go and help us solve the problem. You can either have separate, smaller diagrams for each problem or one big diagram for the whole game. Either way is fine, I think.

3) Don't erase old diagrams. They can be useful in future questions. We didn't encounter that here, of course, since we did just one question, but this is an important thing to remember on test day.

4) Read the rules carefully and be sure to follow them. 1 misread rule can mean several lost points on your LSAT score.

5) Retool your diagram when it doesn't eliminate 4 answer choices.

6) Use trial and error to fill in the diagram. Just try groupings that are within the rules, and see if they help to eliminate more answer choices. You have time to do this, and you'll get faster and faster with more practice. When I started studying for the LSAT, it could take me 20 minutes to do a single game. By test day, I had it down to 4 or 5. This is possible for most anyone with a lot of practice, I think.

7) Rewriting the rules using the symbols (rule i might be written as "LP", for example, to show that they're bought on the same day) is good for some people, and bad for others. Personally, I found it was a waste of time for me, since I ended up rereading the written rules anyway and not looking at my symbols. For other people, the rules being written with symbols is really helpful. Find out what works for you!