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

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

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28 Apr 2013, 14:43
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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.
[Reveal] Spoiler: OA

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

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28 Apr 2013, 14:55
1
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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
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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28 Apr 2013, 15:27
i have a doubt regarding option 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

as per my understanding use of "HAVE"..makes the tense perfect tense.
so if that is true dont you think the process accepting donation and disrespecting pollution control measures are in effect even after 1988.
if that is so then in year 1989 number of smog days should increase in place of decrease.

suggest me where i am wrong.

thanks

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

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28 Apr 2013, 15:41
shaileshmishra wrote:

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

as per my understanding use of "HAVE"..makes the tense perfect tense.
so if that is true dont you think the process accepting donation and disrespecting pollution control measures are in effect even after 1988.
if that is so then in year 1989 number of smog days should increase in place of decrease.

suggest me where i am wrong.

thanks

SKM

No, if they find out that some industies were not respecting the limits, stricter controls will be made next year. It's reasonable to think that this will happen, so less pollution will be in the air next year.

Your "reasoning" is: high levels in 88 => proof that some industries were cheating => higher levels in 89. I think this is not logical (it doesn't make sense)...
Moreover we know for sure that the levels in 89 were lower! Something must have caused this, some industries that were not respecting the limits is an excellent reason and explanation for that. (again, it is reasonable to think that after that finding those industries will not be able to corrupt the officials and exceed the limits anymore)

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

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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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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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29 Apr 2013, 11:56
Bit skeptical 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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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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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.

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

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15 May 2013, 00:50
1
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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.

(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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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.

(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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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?

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

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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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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]

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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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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
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] 22 Mar 2017, 21:05
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