This tip for improving your GMAT score was provided by David Newland at Veritas Prep.
An extremely helpful way to ace assumption questions is to accept the conclusion and the premises as true and then see which answer choices must be true, based on those. In other words turn the assumption question into an inference question.
Although assumption questions are typically categorized as a type of strengthen question, they actually have much more in common with inference questions. Inference questions require answers that “must be true” and most incorrect answers are “out of scope.” The same is true of assumption questions. Since an assumption is required by the argument, it essentially “must be true.”
Let’s take the simple example of a conclusion: “This car is green.” What are we assuming? Are we assuming that “all cars are green?” No. That would be more appropriate as a strengthen answer and is certainly not required as an assumption should be.
To find out what we are assuming, we can treat this assumption as an inference. First we accept the truth of the conclusion that “this car is green.” Then we look for the answer that must be true. If this car is green it must be true that “some cars are green.” By accepting the premises and the conclusion, we can simplify the process by looking for the answer choice that must be true. This is the same technique that we use to solve an inference question.
Try this problem from Official Guide to the GMAT 13th edition (be sure to turn the assumption into an inference):
Because no employee wants to be associated with bad news in the eyes of a superior, information about serious problems at lower levels is progressively softened and distorted as it goes up each step in the management hierarchy. The chief executive is, therefore, less well-informed about problems at lower levels than are his or her subordinates at those levels.
The conclusion drawn above is based on the assumption that:
(A) problems should be solved at the level in the management hierarchy at which they occur
(B) employees should be rewarded for accurately reporting problems to their superiors
(C) problem-solving ability is more important at higher levels than it is at lower levels of the management hierarchy
(D) chief executives obtain information about problems at lower levels from no source other than their subordinates
(E) some employees are more concerned about truth than about the way they are perceived by their superiors.
Now treat the premises and the conclusion as true and find the answer choice that must be true. Remember that, as with inference questions, most answers you eliminate will be slightly out of scope of the stimulus.
Treating everything in the stimulus as a fact, we find that 1) information about serious problems is softened and distorted as it moves up in the management hierarchy and 2) the chief executive is less well-informed about serious problems at lower levels than are the people at those levels. Which answer must be true based on this information?
Choice A indicates where problems “should” be solved and is out of the scope of this argument. The argument does not talk about what should happen but rather than the upper management is less well-informed. Choice B also talks about what should happen and while it seems like a fine suggestion, this is not something that must be true based on the argument. Choice C is out of this argument’s scope: You do not know where problem-solving is most important, based on this stimulus. Choice E seems reasonable but is also not something that must be true, while it is likely that some employees are more concerned about truth, that is not something that must be true, based on these facts.
Choice D is the correct answer. If chief executives are less well-informed because information is softened on the way to them, then it must be true that they do not have other ways of obtaining more accurate information. If they did have other ways of obtaining this information, they would not be less well-informed.
Treat assumption questions like inference questions and you can quickly eliminate answer choices that seem reasonable but are out-of-scope. Look for the answer that must be true, and you will be on your way to acing assumption questions.
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