Practice Problem

[joshmercer80]

I was having a bit of difficulty setting up these 3 problems a la Atlas LSAT style. I was wondering if any of you guys could enlighten me on how to best visually represent these problems and their respective inferences.

Al, Bob, and Lois order exactly two cold drinks each. The drinks consists of four colas, one root beer, and one ginger ale.
- Exactly three of the drinks are ordered with ice.
- Bob orders at least one cola.
- Exactly two of the colas are ordered with ice.
- Lois orders two drinks without ice.

An art collector owns five paintings, each which contains only two colors. Three of the paintings are by Picasso, one is by Monet, and one is by Stella. Three of the paintings contain blue, three contain red, two contain green, and two contain yellow.
- No painting contains blue and green.
- At least two of the paintings contain both red and blue.
- At least one of the Picasso's contains green.
- The Stella contains yellow.

Danielle has ten Siestaware bowls, each of which is displayed on one of three shelves: top, middle, and bottom.
- A, B, and C are dark blue.
- D and E are light blue.
- F, G, and H are red.
- I and J are yellow.
- All of the bowls of a single color are not displayed on the same shelf.
- D, G, and H are displayed on the top shelf.
- A and E are not displayed on the same shelf.

I was trying to "classify" which technique these would fit under such as open assignment or 3D numbered ordering but was unable to devise an efficient way of organizing the facts and conditions. Please show me how you guys would tackle these. Thank you.

[bbirdwell]

Hi! Thanks for posting on the forum.

My first reaction is that these are clearly not official LSAT games, and they're in fact quite poor imitators. "Really bad" is the phrase that comes to mind. Almost so bad that practicing them won't help with the actual LSAT. Almost. They're worth a few seconds of going through the motions to see how you can organize them.

Speaking of organization, it's very important that you understand why we bother naming various "categories" for games. We don't do that because every game you'll encounter will fit neatly into a memorized schema.

There are about 4 basic tasks that we see LSAT games perform. There a couple of common flavors, or variations on each of these tasks that we think appear often enough to merit giving them a name - this makes them easier to talk about.

But this is just a starting point. It's like saying there are artists, musicians, and writers out there. These are the basic classes of a few different kinds of people, but within those groups there are bound to be individual variations, and there are bound to be individuals that share characteristics of more than one of those classes.

On the LSAT, within limits, the harder games will have twists and turns and variations. Flexibility and a cultivated ability to adapt and improvise lead to top scores.

That said, I attempted to diagram the first two setups in the attached .pdf (below). The third was simply not worth the time.

Each of the first two is basically what we would call a "closed assignment" game. That is, we are assigning elements to one another (folks to drinks, colors to paintings), and we know how many of each goes where (2 drinks/person, 2 colors/painting + 3 Picasso's, etc.).

For the first game, there is the added element of attaching "ice" to three of the drinks. This is easy enough. Ri is root beer with ice, Ci is cola with ice, etc. I found zero inferences to make on this game after setting it up. It's clear that the ice will go to Al or Bob, but the distribution of drinks is wide open.

On the second game, we can make one genuine inference, perhaps two. The first is that one of the Picasso paintings must be Red and Blue. We have to have at least two RBs. The Stella has Yellow, and there can be at most 1 Monet that is RB. Therefore at least one Picasso is RB.

That the Picasso with G must also have either Y or R is also sort of an "inference," though rather obvious, yet perhaps worth jotting down on the diagram.

My advice going forward would be to focus on flexibility and principles that carry over from game to game rather than rigid memorization, and get some official LSAT games to practice with.

You might check out the Logic Challenges that we write: http://www.atlaslsat.com/logic-games-practice.cfm

We think they're pretty good, though we do not recommend them over official LSAT material!

Hope that helps! Best of luck with your preparation.

[joshmercer80]

Thank you, thank you, thank you. Yes those problems seemed way out in left field but I assumed maybe it was just me. I felt like I was taking crazy pills. I will get some official LSAT problems and thank you for the help on those two problems. I wasn't too far off on the inferences but was a bit surprised on the first one when I couldn't make any either. Thank you again.