ajmekal wrote:
A detailed explanation, please?
IMO B is correct as "unlike other birds" is used and secondly "unique abilities" is mentioned, both of which signify that only hummingbirds perform can these activities.
Option A refutes the argument by using "some". "None of the other" would have been an equally valid choice?
Please share your thoughts.
Great question ajmekal, and here's the thing to be aware of regarding the use of the word "some."
"Some" can represent any plural number.
If it is true that very few people like swimming, then "some people" like swimming.
If it is true that most people like swimming, then "some people" like swimming.
If it is true that all people like swimming, then still, "some people" like swimming.
At the same time, people don't necessarily think of "some" as representing "all" or "most." "Some" has multiple connotations, and can be perceived as representing a relatively small fractional proportion of a total.
Because "some" has these connotations, it is used in GMAT Critical Reasoning questions to obscure the meanings of choices, and to make incorrect answers seem correct and correct answers seem incorrect.
In this case, the idea is that all birds other than the hummingbird cannot hover. Clearly, if all birds other than the hummingbird cannot hover, then it is true that some birds cannot hover.
So, if you agree that the passage indicates that only hummingbirds can hover, which inference is actually somewhat debatable, then (A) is correct.
(Whether choice (A) is actually correct is debatable, as the passage could be interpreted as saying that only the hummingbird can perform all of the "several feats of acrobatic flight," leaving open the possibility that other birds can perform one or more of those feats, just not all of these feats.)
_________________
★
★
★
★
★
250 REVIEWS
5-STAR RATED ONLINE GMAT QUANT SELF STUDY COURSE
NOW WITH GMAT VERBAL (BETA)
See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews