siddharth86 wrote:
In the years since the city of London imposed strict air-pollution regulations on local industry, the number of bird species seen in and around London has increased dramatically. Similar air-pollution rules should be imposed in other major cities.
Each of the following is an assumption made in the argument above EXCEPT:
(A) In most major cities, air-pollution problems are caused almost entirely by local industry.
(B) Air-pollution regulations on industry have a significant impact on the quality of the air.
(C) The air-pollution problems of other major cities are basically similar to those once suffered by London.
(D) An increase in the number of bird species in and around a city is desirable.
(E) The increased sightings of bird species in and around London reflect an actual increase in the number of species in the area.
fameatop wrote:
Hi Mike,
I am not able to understand how come option B is incorrect & A is correct. Can you kindly clear my doubts. Waiting eagerly for your valuable inputs. Regards, Fame
I like this question.
As for
(B) --- The purpose of "
air-pollution regulations on industry" is to improve the air quality. Of course, if the regulations are poorly written, they might not achieve this purpose. This argument talks about passing these regulations, and then it talk about more birds --- what's the link? The link has to be --- the regulations worked, that is to say, they achieved the end for which they were designed. Notice that the opposite of this ---- "
air-pollution regulations on industry have little effect on air quality" ---- would be a crippling objection to this argument.
(B) is a bonafide assumption.
By contrast,
(A) contains those problematic word "almost entirely" --- any all-inclusive language (all, every, each one, always, etc. etc.) is very very hard to demonstrate and justify. There are always exceptions. Without reading the prompt at all, I figured out this was the one that wasn't an assumption --- the language is too extreme.
Suppose there's are many cities in which local industry is responsible for, say, 40% of the city's air pollution problem, and cars are responsible for 60%. Many post-industrial cities, such as San Francisco, have little in the way of traditional industries, but they have a lot of car traffic. This is a scenario in which
(A) is false, yet even if only some of the air pollution problem is caused by local industries, reducing what air pollution is caused by the industries would still be a worthwhile goal. We can negate
(A) and still justify the argument, so
(A) is not an assumption.
For more on assumptions, see this blog:
https://magoosh.com/gmat/2012/arguments- ... -the-gmat/Mike