I received a PM on this one...
It is amazing how many of the questions floating around turn out to be LSAT questions.
This one is from the December 1999 LSAT Test, Logical Reasoning Section 1, question #16.
This is an excellent example of an LSAT question that can be studied for the GMAT.
It is one of the main question types, an inference question, and it is within the first 16 questions (just barely!). These are the qualities of a question that transfers most directly to the GMAT.
How to approach an inference question
The way to approach an inference question is through Process of Elimination.
Here are the steps:
Step 1: Read the question stem and recognize that it is an inference question. The best way to recognize and inference question is the fact that conclusion is in the answer choice. Many, many official GMAT question stems will literally say, "which of the following conclusions..." so that is a dead give away that you have an inference question. If the question stem is not so obvious, look for other clues in the questions stem that let you know that the conclusion is in the answer choices and not in the stimulus above.
For example, this question stem says "Which one of the following statements is most strongly supported by the information above?" So ask yourself, what kind of thing "is supported"? A conclusion is supported. A premise is not supported it supports. So when this question stem says "which of the following...is most strongly supported" You can read that as "which of the following conclusions" and you know that you have the conclusion in the answer choices and therefore an inference question.
Step 2: Read the stimulus, focus more on scope than specifics. Treat an inference question like a reading comprehension passage, don't get caught up in the details.
Step 3: Move to the answer choices and begin to eliminate those that could be false. Don't focus on whether something could be true. Anything could be true! Remember the correct answer Must Be True and everything else could be false.
There are primarily four categories of answer choices that could be false:
1) Out of scope
2) Predictions
3) Must Be False
4) Commands.
Let's apply the process to this question.
The scope of this stimulus is "zoos and the relationship between zoos and endangered animals." If we need to get more detailed we can glance back up at the stimulus.
Answer Choice A) "Zoos have played an essential role in educating the public about endangered species." This is close. One way to check this is to ask yourself "does it say that they educate the public about endangered species"? The stimulus does not state this. Out of scope.
B) "Some specimens of endangered species are born and bred in zoos." This has the word "some," which is a nice thing to find in an inference answer choice as it gives us a greater possibility of Must Be True (as opposed to "all," which is much harder to prove. Looking at the stimulus we see that "many zoos now maintain breeding stocks for continued propagation of various species."
I believe that Ahnan mentioned this...Notice that there is a small gap in answer choice B. It does not say for sure in the stimulus that the animals bred in the zoos, or in the captive breeding programs also in the stimulus, are endangered species. It is reasonable to think that "some" of these animals would be endangered. Luckily the question stem here is not "MUST BE TRUE" but rather "Most Strongly Supported." So B is a strong contender.
C) "No zoos exploit wild animals or endanger the survival of species." This is a tough statement to prove as even remotely true. NO zoos exploit...? Where is this in the stimulus? This would require some substantial proof and this is not discussed.
D) "Nearly all of the animals in zoos today were born in captivity." This is easier to prove than choice C since it says "nearly all" instead of the complete absolute "no zoos" in choice C. However, this still would require a high level of proof. We only know that most animals today are from captivity. But this does not mean nearly all the animals in the zoos.
E) "The main purpose of zoos has shifted from entertainment to education." The first sentence mentions entertainment and education, but not in the rest of the stimulus. And this does not say that the main purpose has shifted.
