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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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23 Jun 2015, 23:24
If a new and far accurate spectrometer was installed in December 1988 , it is possible that previous spectrometer was inaccurate and showed high level of pollution. In this case B can help in explaining the trends of pollution. Experts please help with this line of reasoning.

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

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28 Sep 2015, 18:46
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In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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22 Aug 2016, 00:39
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.

1986 => 20 days with air pollution and smog alert
1987 => new air pollution control => smog alert : 31 days
1988 => new air pollution control => smog alert : 39 days
1989 => smog alert : 16 days

As per question stem, 87 & 88 is showing a bizarre increase in smog alert days despite monitoring.
What could be the reason

1> Air pollutants, other than Ozone & CO, has reached to the peak level. Contributing in SMOG.

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. :- "invented" doesn't mean that they are used.

(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. Now that can be the reason. If lets say earlier 100 mm, and there were 31 days (15 with below 50 & 16 above 50), now it is 50 mm so tonly 16 above 50mm will be considered.

(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. :-

D should be helping.
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.
BUt lets say there are some companies that are exempted from using Spectrometer. so the air pollution from these companies will contribute in smog. so Smog days alert are higher. But this explains only situation of year 88. what about 87?

But it is helping to understand the increase of year 88.

(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.

I think D should be the correct answer.

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

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22 Aug 2016, 18:26
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.

Hi guys, let me put my rationale up in here...

(A) Since the air pollution control measures were put into effect until November of 1988, it is helpful in explaining why the air pollution levels decreased until 1989, even though in early 1987 new air pollution control measures were enacted.
(B) A new gas spectrometer was invented, first of all it is not stating that it was used by the Pollution Control Board of Los Diablos, and also it is wrongly to assume that a far more accurate gas spectrometer would make the measurement increase OR even decrease, we just know is more accurate but not in which way or anything, so this one is not helpful.
(C) If the scale was revised in February of 1989, this could prove helpful in explaining the decrease in air pollution levels in 1989.
(D) Although many of you think this is the best answer this one is actually VERY helpful in explaining why there is a decrease in the air pollution levels in 1989. If the mayor was found to have accepted (somewhere in the past) donations and exempted (in the past, as well) some industries from the air pollution control measures, then it is explaining why even though there were new air pollution control measures enacted in 1987 there was an increase for the following two years in the air pollution levels and then a decrease until 1989, after this was found out and those companies were no longer exempted from the measures, I mean if there was a case of corruption just publicly found out, would you think that the companies would still be exempted anymore, nope they will no longer be exempted.
(E) I think this one does not need any explaining whatsoever is pretty straightforward, may be even the most helpful in explaining the air pollution levels.

Hope this is helpful for you guys with doubts!

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

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09 Nov 2016, 11:15
kinjiGC wrote:
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.

The comparison has to be between 1987 and 1989, not between 1988 and 1989.
In early 1987, new air pollution control measures were enacted.
In 1989 it is two years since early 1987. That is the time when the results will start to show.
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In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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11 Nov 2016, 15:36
1
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For me, B is correct. My analysis is below...

Structure
Contrasting Fact 1:
In 1986, City LD had 20 days on which air pollution reached unhealthful amounts --> Smog alert into effect.
In early 1987, new air pollution control measures were enacted, but[/highlig[highlight]ht] LD had smog alerts on 31 days that year and on 39 days in 1988.

Contrasting Fact 2:
In 1989, however, the number of smog alerts in LD dropped to sixteen.

LD's main air pollutants: O3 & CO,
Since 1986 the levels of both have been monitored by gas spectrography.

Pre-thinking
We have to find the option that explains the least the contrasting facts. So we can star by pre-thinking some explanations of both contrasting facts:
What if levels of both pollutants remain in the environment for at least two years?
What if pollutants' limit levels were drop significantly in 1987 when the new control measures were enacted?
What if gas spectrography device was not correctly caliber?

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988. Correct
Help to explain Both contrasting points. this option would justify the rise in the number of alerts in the city for both 1987 and 1987; and the drop of alerts in 1989.

(B) In December of 1988, a new and far more accurate gas spectrometer was invented. Incorrect, so correct choice!
This option is OFS. The invention of a more accurate gas spectrometer doesn't mean that LD city used them to measure pollution.

(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. Correct!
Aligned with pre-thinking.. in the revision they probably increase the pollution limit, so this fact explains a drop in the number of alerts.

(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
If he accepted money in exchange for an exemption of the execution of measures, those local industries, knowing that were not going to be punished, were deliberatly contaminating the environment, explaining the high number of alerts during 1987 and 1988. Then, a drop on alters in 1989 happened after the mayor was found to receive bribes.

(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area. Correct
Aligned with pre-thinking.

Hope the analysis helps!

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

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22 Mar 2017, 21:05
This question takes assumptions so i doubt it is an official question.
Please can someone tell me, what is the source of this question?
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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03 Jul 2017, 01:57
Spectrography for air and spectrometer for glass do this statement directly Meking vulnerable conclusion so B is the correct one

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

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03 Jul 2017, 03:21
I immediately chose B because:

1) Just because a new spectrometer was invented, doesn't mean it was actually implemented.
2) Even if it was implemented, there's no way it can explain the difference, only that a more accurate reading will provide a difference.

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

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07 Jul 2017, 10:39
Imo B
A very good question .
A more gas spectrometer is invented but it does not tell us that it was used hence does not impact.
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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08 Jul 2017, 23:26
I was stuck between C & B, as in C, it states a thing which happened in 1989, which would obviously not have any effect on the past, making it the least helpful thing out of the all.

Please correct me where i am going wrong.

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

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22 Jul 2017, 00:30
There is a lot of dispute about the OA. Could the experts please review the choices and provide an explanation.
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In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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22 Jul 2017, 03:41
jedit wrote:
There is a lot of dispute about the OA. Could the experts please review the choices and provide an explanation.

Hi jedit ,

B is the correct answer and has been very well explained above.

Let me know your specific doubts so that I can help get those resolved.

Just remember one thing:

The question is about LEAST explain.

B is saying they got more accurate. If they got more accurate, they should have increased the number of days rather than decreasing the count.
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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26 Jul 2017, 08:56
Merged topics. Please, search before posting questions!
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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19 Aug 2017, 03:04
I am not quite convinced with the OA. I think that the answer should be D.

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

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18 Sep 2017, 05:41
(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
Put into effect in Nov 1988 means by 1988 jan -Nov much pollution already accounted so more days but next year since it was in regulation => less days => Eliminated

(B) In December of 1988, a new and far more accurate gas spectrometer was invented.
LEAVING THIS POINT => POE This is the Answer

(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.
In feb 1989 revision to scale may have caused << days in 1989 due to change in readings.=> Eliminated

(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.

In 1988 Mayor accepted donations and in return was asked for exemption of those companies which gave donations => next year less days , Since its not mentioned Jan 1988 mein li donation ya 31 Dec 1988 so we cant assume anything-> just think that us saal ko chod k next year se exemption. => Eliminated

(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.
=> may explain upto some point 1986 +>2 => >1988 tak break down ho jayega => 1989 less days => Eliminated
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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19 Sep 2017, 06:37
What is the final answer for this?? Is it D?

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Re: In 1986, the city of Los Diablos had 20 days on which air   [#permalink] 19 Sep 2017, 06:37

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