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In 1986, the city of Los Diablos had 20 days on which air

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 28 Apr 2013, 17:07
Zarrolou wrote:
In 1986 20 days .
In early 1987, new air pollution control measures were enacted, 31 days
In 1988 39 days.
In 1989 16 days.

Which of the following statements, assuming that each is true, would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989?

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
Put into effect at the end of 1988, so the result will be seen in 1989. That's what happens (only 16 in 89), so it's a good explanation
(B) In December of 1988, a new and far more accurate gas spectrometer was invented.
CORRECT
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered unhealthful.
Review of the scale , raising or lowering the levels (we do not know). Take the case of higher levels => less days of high pollution. It could explain the drop in 89.
(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures
So in the years prior to 88 the high levels were caused by those industries. In 89 those industries will not cause high pollution=> drop in 89. Good explanation
(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.
So the pollution will remain in the air for 2 years minimum. We'll se the result of the 87's mesures in 89(2 years later). That's what happens, so is a good explanation



Excuse me Sir why in your opinon B is correct ??
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 29 Apr 2013, 00:12
carcass wrote:

Excuse me Sir why in your opinon B is correct ??


hi carcass,

IMO B

because its nowhere stated that this new and far more accurate gas spectrometer which was invented was used for monitoring purpose.

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 29 Apr 2013, 11:56

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 29 Apr 2013, 23:40
I chose the truly out of scope option. The others try to point us in some direction or some line of reasoning.

Might be a Kaplan question - they sometimes need a leap of faith for some options.. :|

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 14 May 2013, 19:57
Zarrolou wrote:
In 1986 20 days .
In early 1987, new air pollution control measures were enacted, 31 days
In 1988 39 days.
In 1989 16 days.

Which of the following statements, assuming that each is true, would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989?

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
Put into effect at the end of 1988, so the result will be seen in 1989. That's what happens (only 16 in 89), so it's a good explanation
(B) In December of 1988, a new and far more accurate gas spectrometer was invented.
CORRECT
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered unhealthful.
Review of the scale , raising or lowering the levels (we do not know). Take the case of higher levels => less days of high pollution. It could explain the drop in 89.
(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures
So in the years prior to 88 the high levels were caused by those industries. In 89 those industries will not cause high pollution=> drop in 89. Good explanation
(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.
So the pollution will remain in the air for 2 years minimum. We'll se the result of the 87's mesures in 89(2 years later). That's what happens, so is a good explanation



B: Ths can actually support.

The new spect. can report a lower pollution range as this is more accurate. Since this is instld in 1988, any further reading can be lower than those of 1987 and 86.

IMO D:

If the industries were exempted, they have little incentive to control the pollution they cause. So, the level might actually go up.

Please comment

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 15 May 2013, 00:50
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Argument:
In los Diablos smog alerts happens when air pollution reached unhealthful amounts.
Fact1: 1986- smog alerts on 20 days
Fact2: early 1987- new air pollution control measures were enacted.
Fact3: 1987-smog alerts on 31 days
Fact4: 1988- smog alerts on 39 days
Fact5: 1989- smog alerts on 16 days
Fact6: The main air pollutants in Los Diablos are ozone and carbon monoxide, and since 1986 the levels of both have been monitored by gas spectrography.

Pre thinking
According to fact the main air pollutants are ozone and carbon monoxide and both are monitored using gas spectrography since 1986 so measuring technique can’t be cause of pollution change unless some changes happens in gas spectrography.
Pollution controls were enacted in early 1987 and pollution actually rose after that till 1988 and then came down in 1989.Looks like it took some time for the effects of measures taken in 1987 to start controlling pollution.

Analysis of answer choices:
(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
INCORRECT: This helps in understanding why it took time for pollution to go down by 1989.

(B) In December of 1988, a new and far more accurate gas spectrometer was invented.
INCORRECT: This can help in understanding the reading difference in 1989 if we assume that the gas spectrometers earlier were giving higher readings than the real readings. Also we have to assume that control measures were not having much effect and thus pollution increased from 1986 to 1988.
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered un healthful.
INCORRECT: This can helps us in understanding why pollution alerts went down in 1989 if we assume that the level for un healthful was raised. Also we have to assume that control measures were not having much effect and thus pollution increased from 1986 to 1988.

(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures.
CORRECT: this means that lesser industries are using air pollution control measures and hence air pollution should go up. However its went down in 1989 and it can’t be explained from this answer choice.

(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.
INCORRECT: This helps in understanding why it took time for pollution to go down by 1989.

So D in my opinion as well . I believe official answer is incorrect.
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 15 May 2013, 01:08
ssbisht wrote:
Argument:
In los Diablos smog alerts happens when air pollution reached unhealthful amounts.
Fact1: 1986- smog alerts on 20 days
Fact2: early 1987- new air pollution control measures were enacted.
Fact3: 1987-smog alerts on 31 days
Fact4: 1988- smog alerts on 39 days
Fact5: 1989- smog alerts on 16 days
Fact6: The main air pollutants in Los Diablos are ozone and carbon monoxide, and since 1986 the levels of both have been monitored by gas spectrography.

Pre thinking
According to fact the main air pollutants are ozone and carbon monoxide and both are monitored using gas spectrography since 1986 so measuring technique can’t be cause of pollution change unless some changes happens in gas spectrography.
Pollution controls were enacted in early 1987 and pollution actually rose after that till 1988 and then came down in 1989.Looks like it took some time for the effects of measures taken in 1987 to start controlling pollution.

Analysis of answer choices:
(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
INCORRECT: This helps in understanding why it took time for pollution to go down by 1989.

(B) In December of 1988, a new and far more accurate gas spectrometer was invented.
INCORRECT: This can help in understanding the reading difference in 1989 if we assume that the gas spectrometers earlier were giving higher readings than the real readings. Also we have to assume that control measures were not having much effect and thus pollution increased from 1986 to 1988.
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered un healthful.
INCORRECT: This can helps us in understanding why pollution alerts went down in 1989 if we assume that the level for un healthful was raised. Also we have to assume that control measures were not having much effect and thus pollution increased from 1986 to 1988.

(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures.
CORRECT: this means that lesser industries are using air pollution control measures and hence air pollution should go up. However its went down in 1989 and it can’t be explained from this answer choice.

(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.
INCORRECT: This helps in understanding why it took time for pollution to go down by 1989.

So D in my opinion as well . I believe official answer is incorrect.


great work infact...
but would like to correct your understanding for option D...lesser industries followed air pollution control measure in 1988....it is describing only for the year 1988...and not after that.....dont get confused with the USE OF HAVE...it is no more acting as a verb rather as a infinitive.....
hope its clear...

SKM
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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BlueRobin wrote:
In 1986, the city of Los Diablos had 20 days on which air pollution reached unhealthful amounts and a smog alert was put into effect. In early 1987, new air pollution control measures were enacted, but the city had smog alerts on 31 days that year and on 39 days the following year. In 1989, however, the number of smog alerts in Los Diablos dropped to sixteen. The main air pollutants in Los Diablos are ozone and carbon monoxide, and since 1986 the levels of both have been monitored by gas spectrography.
Which of the following statements, assuming that each is true, would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989?

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
(B) In December of 1988 a new and far more accurate gas spectrometer was invented.
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered unhealthful.
(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures.
(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.


My initial pick was D too. But I guess after reading it the second time , I see why B makes sense.

Quote:
(B) In December of 1988 a new and far more accurate gas spectrometer was invented..

As other people have pointed out , it only says spectrometer was invented . No mention of it being used to monitor the levels.

Quote:
(D) In 1988 the mayor of Los Diablos was found to have acceptedlarge campaign donations from local industries and to have exempted those same industries from air pollution control measures. .

No doubt , the pollution increases , if mayor exempts those industries from air pollution measures. So accepting donations to exempt those industries , meant increase in air pollution. If we focus on the bold part above in D , it says in 1988 , the mayor was found to have accepted. It doesn't say that mayor ACCEPTED in 1988 and EXEMPTED the industries IN 1988. He was FOUND to have accepted in 1988. He might have accepted the donations before 1988 or in the middle of 1998 or end of 1988.They just found that thing in 1988. The exemption might have happened in 1987. Or if they found out by the end of 1988 , then exemption might have happened till they found out , in 1988. This kinda explains why the pollution increased till 1988. And mebbe once they found out in 1988 , what mayor had done , they might have reverted the exemptions , which is why in 1989 pollution went down . I know it is bit of a stretch to make these assumptions , but when we are to choose between B and D (In B - where you make an assumption that invented meant used + cant justify yet as to why did new and accurate instruments show lower pollution levels) , the assumptions what we made in D seems safer.

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 22 Feb 2014, 05:51
B says about invention which does not imply to the question asked. So, B.

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Re: Los Diablos [#permalink]

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bigfernhead wrote:
I recall this question and

The OA is B apparently, because even though the gas spectometer was invented, it doesn't mean it was used.

But I'm still sticking with D! :-)


B is right

Firstly, Argument is asking about variation in pollution level from 86 to 89
and What measure do we have in argument - number of occurrences/ frequency of alert days on which air pollution reached unhealthful amounts and a smog alert was put into effect. (highlighted part is in the first line of arg.)

Secondly, What's wrong with D - if some industries are getting exemption "from air pollution control measures."
Then, surely frequency will be affected.

B is right just because of what 'bigfernhead' has mentioned about B.
Hope it helps !
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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B, it's the right answer. B said that a new gas spectrometer was invented, but we dont know if it was used!!!

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 28 Mar 2014, 09:18
IMO, D
What if the companies from which the mayor accepted dnations were not contributing significantly to the air pollution in the years before ? The companies were donating just out of goodwill and their donations helped curb the pollution ?

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 09 Apr 2014, 15:45
Minheequang wrote:
In 1986, the city of Los Diablos had 20 days on which air pollution reached unhealthful amounts and a smog alert was put into effect. In early 1987, new air pollution control measures were enacted, but the city had smog alerts on 31 days that year and on 39 days the following year. In 1989, however, the number of smog alerts in Los Diablos dropped to sixteen. The main air pollutants in Los Diablos are ozone and carbon monoxide, and since 1986 the levels of both have been monitored by gas spectrography.

Which of the following statements, assuming that each is true, would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989?

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.-
(B) In December of 1988 a new and far more accurate gas spectrometer was invented.
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered unhealthful.
(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures.
(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.


The issue is between B & D
B- A new instrument was invented in1988-1. Does not imply it was put to use...This is not a strong excuse to justify B..It cannot be the basis for choosing an option..It can be considered for granted that the meter was put to use..Now,What if the more accurate spectrometer registered the pollution levels just below the red mark & hence the alert days were reduced in 1988

D-Exempting the industries for donations--- :shock: ..This is as good as it can be..--->Exemption-->More Pollution-->More days with smog alerts expected
-->But we have less days-->So it least helps in explaining the observation.
Vercules wrote:

The question asks us to find an answer choice that is LEAST helpful in explaining the pollution levels between 1986 and 1989. (B) may explain why the smog alerts decreased in 1989, but it will not explain the rise in pollution level in 1987 or 1988.

(D) on the other hand helps to explain the levels, because the Mayor "was found" to have accepted donations and exempted industries from pollution control measures. In 1988 it was found, so it is possible that he could have been taking donations in the past also; it could explain the pollution levels in 1987 and 1988. Thus, (D) explains.


Vercules

B- Rise in pollution levels was due to increase in pollution and the decrease was due to the reasons explained above....
Consider on a day in a year 1987 when the pollution level is at 701,which is greater than the red mark of 700.So we have an alert.
With the new meter the values were accurately found to be 699 and hence no smog alert..This could have happened on several occasions and so the decrease

D-Here when we assume that it is possible that Mayor took donations earlier too.We are assuming a premise outside the scope of the argument to be true.This is completely unacceptable & anyways to justify the trend we are further assuming that he took less donations in 1986,87 & 88 than in 89
-->Assumption over an assumption outside the scope of the argument :shock:

How can anyone ever have a doubt between B & D... :? :shock:
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 10 Apr 2014, 00:47
JusTLucK04 wrote:
Minheequang wrote:
In 1986, the city of Los Diablos had 20 days on which air pollution reached unhealthful amounts and a smog alert was put into effect. In early 1987, new air pollution control measures were enacted, but the city had smog alerts on 31 days that year and on 39 days the following year. In 1989, however, the number of smog alerts in Los Diablos dropped to sixteen. The main air pollutants in Los Diablos are ozone and carbon monoxide, and since 1986 the levels of both have been monitored by gas spectrography.

Which of the following statements, assuming that each is true, would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989?

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.-
(B) In December of 1988 a new and far more accurate gas spectrometer was invented.
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered unhealthful.
(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures.
(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.


The issue is between B & D
B- A new instrument was invented in1988-1. Does not imply it was put to use...This is not a strong excuse to justify B..It cannot be the basis for choosing an option..It can be considered for granted that the meter was put to use..Now,What if the more accurate spectrometer registered the pollution levels just below the red mark & hence the alert days were reduced in 1988

D-Exempting the industries for donations--- :shock: ..This is as good as it can be..--->Exemption-->More Pollution-->More days with smog alerts expected
-->But we have less days-->So it least helps in explaining the observation.
Vercules wrote:

The question asks us to find an answer choice that is LEAST helpful in explaining the pollution levels between 1986 and 1989. (B) may explain why the smog alerts decreased in 1989, but it will not explain the rise in pollution level in 1987 or 1988.

(D) on the other hand helps to explain the levels, because the Mayor "was found" to have accepted donations and exempted industries from pollution control measures. In 1988 it was found, so it is possible that he could have been taking donations in the past also; it could explain the pollution levels in 1987 and 1988. Thus, (D) explains.


Vercules

B- Rise in pollution levels was due to increase in pollution and the decrease was due to the reasons explained above....
Consider on a day in a year 1987 when the pollution level is at 701,which is greater than the red mark of 700.So we have an alert.
With the new meter the values were accurately found to be 699 and hence no smog alert..This could have happened on several occasions and so the decrease

D-Here when we assume that it is possible that Mayor took donations earlier too.We are assuming a premise outside the scope of the argument to be true.This is completely unacceptable & anyways to justify the trend we are further assuming that he took less donations in 1986,87 & 88 than in 89
-->Assumption over an assumption outside the scope of the argument :shock:

How can anyone ever have a doubt between B & D... :? :shock:


Question is asking which option can help to LEAST explain this pattern.

1986-20days
1987-31
1988-39
1989-9

D says in 1988 mayor got donation and he exempted industries from those regulations... and we can see clearly in 1988 smoke alert increased..thus option D explains that why smoke alerts were highest in that year... we should not assume that mayor exempted them in 1989 as well. Option D is sufficient to tell us that observation in 1988 is ok.

B says new accurate spectrometer was developed in 1988... either it should increase the alerts or decrease the alerts... but we can not explain that 9 alerts were due to increased accuracy or any other reason. Thus I think option B LEAST explains the trend of number of alerts.
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 10 Apr 2014, 01:54
PiyushK wrote:
JusTLucK04 wrote:
Minheequang wrote:
In 1986, the city of Los Diablos had 20 days on which air pollution reached unhealthful amounts and a smog alert was put into effect. In early 1987, new air pollution control measures were enacted, but the city had smog alerts on 31 days that year and on 39 days the following year. In 1989, however, the number of smog alerts in Los Diablos dropped to sixteen. The main air pollutants in Los Diablos are ozone and carbon monoxide, and since 1986 the levels of both have been monitored by gas spectrography.

Which of the following statements, assuming that each is true, would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989?

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.-
(B) In December of 1988 a new and far more accurate gas spectrometer was invented.
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered unhealthful.
(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures.
(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.


The issue is between B & D
B- A new instrument was invented in1988-1. Does not imply it was put to use...This is not a strong excuse to justify B..It cannot be the basis for choosing an option..It can be considered for granted that the meter was put to use..Now,What if the more accurate spectrometer registered the pollution levels just below the red mark & hence the alert days were reduced in 1988

D-Exempting the industries for donations--- :shock: ..This is as good as it can be..--->Exemption-->More Pollution-->More days with smog alerts expected
-->But we have less days-->So it least helps in explaining the observation.
Vercules wrote:

The question asks us to find an answer choice that is LEAST helpful in explaining the pollution levels between 1986 and 1989. (B) may explain why the smog alerts decreased in 1989, but it will not explain the rise in pollution level in 1987 or 1988.

(D) on the other hand helps to explain the levels, because the Mayor "was found" to have accepted donations and exempted industries from pollution control measures. In 1988 it was found, so it is possible that he could have been taking donations in the past also; it could explain the pollution levels in 1987 and 1988. Thus, (D) explains.


Vercules

B- Rise in pollution levels was due to increase in pollution and the decrease was due to the reasons explained above....
Consider on a day in a year 1987 when the pollution level is at 701,which is greater than the red mark of 700.So we have an alert.
With the new meter the values were accurately found to be 699 and hence no smog alert..This could have happened on several occasions and so the decrease

D-Here when we assume that it is possible that Mayor took donations earlier too.We are assuming a premise outside the scope of the argument to be true.This is completely unacceptable & anyways to justify the trend we are further assuming that he took less donations in 1986,87 & 88 than in 89
-->Assumption over an assumption outside the scope of the argument :shock:

How can anyone ever have a doubt between B & D... :? :shock:


Question is asking which option can help to LEAST explain this pattern.

1986-20days
1987-31
1988-39
1989-9

D says in 1988 mayor got donation and he exempted industries from those regulations... and we can see clearly in 1988 smoke alert increased..thus option D explains that why smoke alerts were highest in that year... we should not assume that mayor exempted them in 1989 as well. Option D is sufficient to tell us that observation in 1988 is ok.

B says new accurate spectrometer was developed in 1988... either it should increase the alerts or decrease the alerts... but we can not explain that 9 alerts were due to increased accuracy or any other reason. Thus I think option B LEAST explains the trend of number of alerts.


Agreed D explains the trend for 1988..But what about 87 and 89..So are you saying that we again assume the donations were valid for an year only
For B- If you go thru the example I suggested..you can easily explain the observation..at least far better than D..& it is always about the better one
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Re: Los Diablos [#permalink]

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New post 10 Apr 2014, 11:25
Minheequang wrote:
imanonymoususer wrote:
Minheequang wrote:
One more doubt about OA

In 1986, the city of Los Diablos had 20 days on which air pollution reached unhealthful amounts and a smog alert was put into effect. In early 1987, new air pollution control measures were enacted, but the city had smog alerts on 31 days that year and on 39 days the following year. In 1989, however, the number of smog alerts in Los Diablos dropped to sixteen. The main air pollutants in Los Diablos are ozone and carbon monoxide, and since 1986 the levels of both have been monitored by gas spectrography.
Which of the following statements, assuming that each is true, would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989?

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
(B) In December of 1988 a new and far more accurate gas spectrometer was invented.
(C) In February of 1989, the Pollution Control Board of Los Diablos revised the scale used to determine the amount of air pollution considered unhealthful.
(D) In 1988 the mayor of Los Diablos was found to have accepted large campaign donations from local industries and to have exempted those same industries from air pollution control measures.
(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.


A) Explains why number reduced on 1988
B) This does not. If more accurate then the numbers should have increased. -->From which info can you say that it will increase ? I can assume that because a new monitor machine is more accurate, it will prove less smog alert case which otherwise will prove positive. The initial problem in this case is that the control measures didn't work, but a new spectrometer helps solve the problem
C) Explains. Now new threshould is there, which maybe greater than the previous one.
D) Explains. Since companies exempted from air pollution measures, hence the decrease. --> I don't think so. A number of companies are exempted from controlled pollution measures, it means that such companies will pose more pollution. So why does the case of smog alert become fewer ? --> it strengthens the discrepancy
E) Since min 2 years required to break down the pollutants, hence the effects seen after 2 years..

IMO B


In D since companies were exempted from air pollution measures, their pollution level was high, once that in 1988 the mayor was found to accept the donations, the mayor had to stop maing these concesions with the companies and had to start measuring their pollution levels, hence, once measured the companies had to lower their pollution levels. => So D helps explain the drop in 1989

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 20 May 2014, 08:14
We have a nice contest between B and D

Why don't we let one of our in-house experts chime in to solve this one?

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 31 May 2014, 00:34
Zarrolou wrote:
In 1986 20 days .
In early 1987, new air pollution control measures were enacted, 31 days
In 1988 39 days.
In 1989 16 days.

(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.
So the pollution will remain in the air for 2 years minimum. We'll se the result of the 87's mesures in 89(2 years later). That's what happens, so is a good explanation


If Option E) is wrong, how levels of 1988 decreased so dramatically in 1989, it is not yet 2 years.
Can anybody explain why Option E) is wrong.
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 08 Jul 2014, 07:17
MKS wrote:
bigfernhead wrote:
I recall this question and

The OA is B apparently, because even though the gas spectometer was invented, it doesn't mean it was used.

But I'm still sticking with D! :-)


B is right

Firstly, Argument is asking about variation in pollution level from 86 to 89
and What measure do we have in argument - number of occurrences/ frequency of alert days on which air pollution reached unhealthful amounts and a smog alert was put into effect. (highlighted part is in the first line of arg.)

Secondly, What's wrong with D - if some industries are getting exemption "from air pollution control measures."
Then, surely frequency will be affected.

B is right just because of what 'bigfernhead' has mentioned about B.
Hope it helps !


Thanks a lot, It cleared my confusion.

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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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New post 17 Sep 2014, 14:41
Can we get an expert on this?
B and C both seem very much alike to me. They both give a reason that there can be a change in the following year, but not any sense as to what that change is.
Option D talks about the past. If in 1988 it was found that he had exepmted the companies, it does not meant that it isn't rectified in 1989 and that's why the pollution is going down...
Too much "maybe" here for me...

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Re: In 1986, the city of Los Diablos had 20 days on which air   [#permalink] 17 Sep 2014, 14:41

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