GRE Reading Comprehension Inference Questions
There's nothing like a GRE reading comprehension inference question to bedevil the assiduous test-taker. Without enough experience with official ETS material, it can be difficult to judge whether a particular inference is justified by the passage, or whether it's too speculative.
I break inference questions down into two types:
1. "Must be true". For example, if a reading passage says that most phytoplankton species are found at the bottom of a deep-sea canyon, a correct answer choice could be that "relatively few phytoplankton species are found at the rim of the canyon".
2. "Would be silly if untrue". If you're not sure about a choice but you'd feel like a doofus if you tried to construct an argument against it, it's almost certainly correct.
Watch the below video for examples of GRE questions that involve inferences, and how to tell whether an answer choice for one of those questions is justified or not.
Pro tip: After you check out this video, it's important to calibrate your understanding of inference questions by practicing with the official ETS GRE prep books, as well as the ETS Big Book (the old PDF with 27 tests).