Self-study
All of the cargo ships of the Blue Star Line are over 100 meters long, and all of its passenger ships are under 100 meters long. ████ ██ ███ █████ ██ ███ ████ ████ ████ ████ █████ ██████ █████ ███ ██ ███ █████████ ███ █████ █████ ██ ███ ████ ████ ████ ████ █████ █████ █████ ███ ███ ███ █████ ███ ██████ █████ ███ ████████ ██████████ ██ ████ ████████ █████ ██ ████ ████ ██ █████ ██ █████ ███ ██████ ███ ███████████ ████ █████ █████ ████ ███ ████ ████ ███ ██████ █████ ███ ████ █████ ██ █ █████ ████ ████ ██ █████████ ██████ ██ ████ ████████
Stimulus Summary
We're given several descriptions (you can think of them as "rules") about two lines of ships, and a port served by them. The Blue Star Line's cargo ships are all over 100 meters long, its passenger ships are all under 100 meters long, and most of its ships were built before 1980. The Gold Star Line's ships, whether passenger or cargo, are all under 100 meters long and all built after 1980. Port Tropica is open only to these two lines of ships, and can only accommodate ships less than 100 meters long. A cargo ship named the S.S. Coral is docked at Port Tropica.
Analysis: Must Be True
You might be wondering where to start with a list of (mostly) conditionals like this. It would be counterproductive to try to diagram everything here, so it's better to try to draw inferences as you read. Notice that the rules start out more general — the details for the two shipping lines — and then are applied to a specific situation: Port Tropica, and the one specific ship docked there. So a good way to proceed as you read this is just to ask if we know anything else about the more specific situation (Port Tropica and S.S. Coral), given the general rules provided first (the details of the Blue Star and Gold Star Lines).
In other words, the minute we read that Port Tropica is open only to the Blue and Gold Star lines, and only accommodates ships less than 100 meters long, we know it must only accommodate the Blue Star Line's passenger ships, because all the Blue Star Line's cargo ships are above 100 meters long. The port can accommodate both the Gold Star Line's cargo ships and its passenger ships. And since we know the S.S. Coral is a cargo ship docked at Port Tropica, we know it must belong to the Gold Star Line. These inferences are probably a good place to start — we can now go to the answer choices and proceed by elimination.
Analysis by ArdaschirArguelles
18.
If the statements above are █████ █████ ███ ██ ███ █████████ ████ ██ ████ ██ ███ █████ ██ █████
a
The S.S. Coral ███ █████ █████ █████
b
The S.S. Coral ███████ ██ ███ ████ ████ █████
c
Port Tropica is ██████ ████ ██ █████ ██████
d
Port Tropica is ███ ██████ ██ █████ ██ ███ ████ ████ █████
e
All of the █████ ██ ███ ████ ████ ████ ███ █████ ████ ███ ██ ███ █████ ██ ███ ████ ████ █████