Critical Reasoning

thulsy wrote:My home-made analogy:

In a research on cancer patients, a group of lung cancer patients were undergoing a recuperative program that requires daily physical exercises. At the end of the program, the size of the tumor in each of these patients decreased dramatically. Similar recuperative program should be imposed on other cancer patients.

Each of the following is an assumption made in the argument above EXCEPT:

A. In most cancer patients, cancer is caused almost entirely by lack of physical exercises.
B. The recuperative program that requires daily physical exercises has a significant impact on the cancer recuperation.
C. Other cancer patients have disease mechanisms basically similar to those of lung cancer patients.
D. A decrease in the tumor size is desirable for cancer treatment.
E. A decrease in the tumor size in a lung cancer patient reflects improved condition of the patient.

Thanks for the above question. I can recognize the pattern now.

I really did not understand this. The OA should be B. Where did quality of air, come into the picture. The OA should be B. What if, something in the air pollution might have helped the birds to increase or the change in the season might have helped. A is a good competing answer, but B stands out as you simply cannot assume that.

Answer should be a B. Gmatguru, dont u feel that B uses the outside knowledge. It is a wrong answer... it is not assumed.

I would go for B. What is the OA by the way\????

B actually sounds like, Pollution in the world is only because of human activity. who told that.

There can be other reasons for it. The stimulus should say it specifically. TO hold the conclusion i do not need the option B.

Guyzzz help

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. Is it necessary for the conclusion. No.
(B) Air-pollution regulations on industry have a significant impact on the quality of the air. Not absolutely necessary but more necessary than A
(C) The air-pollution problems of other major cities are basically similar to those once suffered by London. Absolutely necessary
(D) An increase in the number of bird species in and around a city is desirable. Absolutely necessary
(E) The increased sightings of bird species in and around London reflect an actual increase in the number of species in the area. necessary


It was between A and B. In the end, to me, B sounded more necessary than A. In fact, A states a very strong thing that polllution is caused entirely by industry, of which, we no clue in the argument.
So A is not necessary at all.

My pick and OA is A

Hope this helps Amit!

Conclusion : Similar air-pollution rules should be imposed in other major cities.
Premise : 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

Now Question asks for an option which is no where related to above as an assumption. SO lets drill down each option and strike it out.


(A) In most major cities, air-pollution problems are caused almost entirely by local industry.
-- This passage is concerned with local industry and this can be one probable assumption which fills the gap between premise and COnclusion. So this option is out .....Striked

(B) Air-pollution regulations on industry have a significant impact on the quality of the air.
---- Lets keep it aside for time being.

(C) The air-pollution problems of other major cities are basically similar to those once suffered by London.
--- London regulation outcome has triggered the conclusion. so its must as assumption. so Striked
(D) An increase in the number of bird species in and around a city is desirable.
---- This is the one result of regulation that triggered the implementation in other cities ....Striked
(E) The increased sightings of bird species in and around London reflect an actual increase in the number of species in the area.
---- This acts as an assumption. If when negated i.e.The increased sightings of bird species in and around London does not reflect an actual increase in the number of species in the area then there won't be any relevance between the premise and conclusion which will lead to fall of conclusion. So its Striked off

Now Option B is remaining ..." Air-pollution regulations on industry have a significant impact on the quality of the air " : This is the correct answer which doesn't act as any assumption for above conclusion to be drawn. Air quality doesn't quantify in the passage conclusion. Negating this i.e. Air-pollution regulations on industry does not have a significant impact on the quality of the air " doesn't affect the premise as the reason can be different for increase in species number and thus doesn't contradict the conclusion too. B doesn't affect the conclusion what so ever

OA is B

shipra wrote:2. 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.

By POE .. D .. Four are assumptions D is not an assumption or fact

Ian Stewart 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:

Often the words in CR questions encourage us to bring outside knowledge to the question. We might think, when reading the above, 'of course air pollution is bad, and should be reduced', and this might lead us to ignore the structure of the argument. The argument says, essentially, "London imposed air pollution laws. The number of birds went up. Therefore the rules should be applied everywhere."

When I see an argument like this, I'll normally replace, in my head, the words with letters. The argument is: "London did X. The number of Y went up. Therefore every other city should do X." Now the argument's structure is clear; the fact that Y went up is the justification for implementing X.

In the original argument, what is the justification for the conclusion? Precisely that there were more birds. It's an unstated assumption that having more birds is a good thing; it's the only justification for improving air quality that is provided. So D is one of the assumptions. That we should apply London's rules elsewhere assumes other cities are similar: C is an assumption. That the increased sightings of birds actually represents an increase in the number of birds is another assumption: E is also assumed.

B is not an assumption explicitly made in the argument. I suppose it's possible that air pollution regulations led to more birds for a different reason than by improving air quality, but that seems far-fetched. Still, if no other answer were good, this would be the choice. A, however, is clearly not assumed in the argument. The argument does not assume that local industry is 'almost entirely' the source of air pollution. It only assumes that regulation on local industry will have a positive effect.

Incidentally, there aren't many birds in London!

______________


(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.

Ian thanks for Explanation

Will such questions have a fact and rest of the choices as assumptions or can Argument be based on only assumptions ..and need to eliminate an non relevant or lees relevant questions

Thanks

Ian Stewart 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:

Often the words in CR questions encourage us to bring outside knowledge to the question. We might think, when reading the above, 'of course air pollution is bad, and should be reduced', and this might lead us to ignore the structure of the argument. The argument says, essentially, "London imposed air pollution laws. The number of birds went up. Therefore the rules should be applied everywhere."

When I see an argument like this, I'll normally replace, in my head, the words with letters. The argument is: "London did X. The number of Y went up. Therefore every other city should do X." Now the argument's structure is clear; the fact that Y went up is the justification for implementing X.

In the original argument, what is the justification for the conclusion? Precisely that there were more birds. It's an unstated assumption that having more birds is a good thing; it's the only justification for improving air quality that is provided. So D is one of the assumptions. That we should apply London's rules elsewhere assumes other cities are similar: C is an assumption. That the increased sightings of birds actually represents an increase in the number of birds is another assumption: E is also assumed.

B is not an assumption explicitly made in the argument. I suppose it's possible that air pollution regulations led to more birds for a different reason than by improving air quality, but that seems far-fetched. Still, if no other answer were good, this would be the choice. A, however, is clearly not assumed in the argument. The argument does not assume that local industry is 'almost entirely' the source of air pollution. It only assumes that regulation on local industry will have a positive effect.

Incidentally, there aren't many birds in London!

______________


(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.

Hi Ian,
Your explanation is great but I still have inclination towards answer D. Would you pls help me clear my mind about this because I still would fall prey to an option like D if the question is changed a little.
My doubt is:
In D, "the increase in no. of bird species is DESIRABLE". Desirable? I don't think so because the author only wants to convey that the increase in number (of bird species) indicates improved/lesser air pollution. It is just an indication & it is NOT that people want to see birds around for they appreciate their beauty or sound. So, desirable is just not the right usage here according to me. But since the OA remains A, I do need to change my thought process. Please help me develop this GMAT perspective. Thank you!
DivineAcclivity

Please reply..
Thank you.

divineacclivity wrote:Please reply..
Thank you.

Please try one more strategy popular with gmat assumption questions. Negate the option D (hope you know how to do it) and the argument will fall flat. This technique is helpful when you have narrowed down your answer choices and you have to decide between the last two.

shipra wrote:2. 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.

I'm between A and B and think both can be the OA. because each of them makes sense in some ways.

My answer is D because this is the only thing which we can't figure out as an assumption in the given argument.

shipra 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.

London Imposes strict air pollution regulation --------- > No of bird species found in and around London Increased dramatically.

Hence, such 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.

Might be true , don't have sufficient information to assume it.

(B) Air-pollution regulations on industry have a significant impact on the quality of the air.

True.

(C) The air-pollution problems of other major cities are basically similar to those once suffered by London.

The author talks about implementation of the said strategy to other cities , so the situation is such that such strict measures can be implemented there as well.

(D) An increase in the number of bird species in and around a city is desirable.

True.

(E) The increased sightings of bird species in and around London reflect an actual increase in the number of species in the area.

True , this is assumed at reaching the conclusion to adopt similar strategy in other major cities.


Hence IMO (A) as it looks better than the other options available...

Here is the question again since it is 3 pages back and we need to know what we are discussing:

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.

OA is A I confirmed this from several sources.

This is much more of an LSAT question than a GMAT question. Remember that we are looking for the answer that is NOT a REQUIRED ASSUMPTION of the argument.

The conclusion to the argument is "Similar air-pollution rules should be imposed in other major cities." See that word "should"? It means that we need to have a reason why this is a desirable path. What evidence do you have that it is desirable? Well the increase in the bird species, right? But where does it say that this is desirable to have more species of birds in and around the city? You are assuming it is desirable. Or rather the argument is assuming. So D is NOT the answer. Because it is a required assumption.

The answer is A "In most major cities, air-pollution problems are caused almost entirely by local industry." The wording of A makes it nearly impossible for this to be an assumption. Assumption answers do not say things like "almost entirely caused." In order to improve (lesson) pollution levels you do not need the thing you are regulating to cause 100% or nearly 100% of the pollution. If industry causes some pollution that is enough to make a difference.

If you look back on page 1 Ian Stewart has given a great explanation there.

A simple way to tackle any "EXCEPT" question is to look for 4 correct choices.
And select the last one as the answer instead of trying to figure out the one which is odd.