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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 2010, 14:52
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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.

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Re: 1000 CR test - 16 [#permalink]

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28 Apr 2010, 15:20
sushantdsahu 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.

B???

A) Knowing that it takestwo years to enact the pollution control measures explains the trend.
B) Just because a far more accurate instrument was invented does not mean it was used.
C)Revising the scale means the way pollution was measured was changed and it could have been high in 1989 too but the lower reading was probably because of the revised scale.
D) This is tricky. This may be the reason why the air pollution was still high in 87 and 88.
E)This explain why the readings were high in 87 and 88 and dropped in 89.

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Re: 1000 CR test - 16 [#permalink]

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28 Apr 2010, 16:09
mbafall2011 wrote:
sushantdsahu 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.

B???

A) Knowing that it takestwo years to enact the pollution control measures explains the trend.
B) Just because a far more accurate instrument was invented does not mean it was used.
C)Revising the scale means the way pollution was measured was changed and it could have been high in 1989 too but the lower reading was probably because of the revised scale.
D) This is tricky. This may be the reason why the air pollution was still high in 87 and 88.
E)This explain why the readings were high in 87 and 88 and dropped in 89.

If we look to the argument:
86 - 20
87 - 31
88 - 37
89 - 16
that means sudden drop.
The question ask us to find which choice is least helpful in explaining the levels of air-pollution?

D says in 88 industries were exempted from the regulations that means there can be a increase but the argument shows a decrease in level. So i thought answer is B.
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Re: 1000 CR test - 16 [#permalink]

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29 Apr 2010, 01:42
mbafall2011 wrote:
sushantdsahu 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.

B???

A) Knowing that it takestwo years to enact the pollution control measures explains the trend.
B) Just because a far more accurate instrument was invented does not mean it was used.
C)Revising the scale means the way pollution was measured was changed and it could have been high in 1989 too but the lower reading was probably because of the revised scale.
D) This is tricky. This may be the reason why the air pollution was still high in 87 and 88.
E)This explain why the readings were high in 87 and 88 and dropped in 89.
[Does it means that the amount of ozone and CO is fixed and fully break down for each year and new package of these gases is created in the atmosphere for further breakdown. I think if this is your reason for negating this choice then it is not correct. Both these gases are in continuous process from 1986 - 1989.]

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Re: 1000 CR test - 16 [#permalink]

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29 Apr 2010, 05:13
My pick is B
Just because a more accurate gas specr was invented doesnot necessarily mean that
it was used to measure pollution in the city. Big assumtions in here
between B and D, B sounds least convincing...

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Re: 1000 CR test - 16 [#permalink]

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29 Apr 2010, 08:57
ykaiim wrote:
mbafall2011 wrote:
sushantdsahu 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.

B???

A) Knowing that it takestwo years to enact the pollution control measures explains the trend.
B) Just because a far more accurate instrument was invented does not mean it was used.
C)Revising the scale means the way pollution was measured was changed and it could have been high in 1989 too but the lower reading was probably because of the revised scale.
D) This is tricky. This may be the reason why the air pollution was still high in 87 and 88.
E)This explain why the readings were high in 87 and 88 and dropped in 89.
[Does it means that the amount of ozone and CO is fixed and fully break down for each year and new package of these gases is created in the atmosphere for further breakdown. I think if this is your reason for negating this choice then it is not correct. Both these gases are in continuous process from 1986 - 1989.]

We are told that any gases already in the air takes two years to break down. Thus, the gases that were part of the measured pollutants in 86 cud have been released earlier and have not broken down yet. Similarly in 87, the gases could have released in 85 and 86 and so on. In 1987 new smog alerts were enacted. Hence in 1988 and 1987 the number of new gases releases would have decreased but the readings were high because of the gases released in previous two years. Two years after the new rules were enacted, the gases had decomposed and no new gases were released and therefore 1989 showed a much smaller measurement.

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Re: 1000 CR test - 16 [#permalink]

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29 Apr 2010, 09:41
Hi,

Thanks for the explanation but still the issue is unclear to be.

It is not mentioned in the stimulus when the two gases released and whether these gases would convert into non-pollutants.

I hope some more explanation can help me.
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Re: 1000 CR test - 16 [#permalink]

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29 Apr 2010, 11:21
ykaiim wrote:
Hi,

Thanks for the explanation but still the issue is unclear to be.

It is not mentioned in the stimulus when the two gases released and whether these gases would convert into non-pollutants.

I hope some more explanation can help me.

Think of it this way: which one is the least explanatory? We dont know when the gases were released, just that in 86 and 87 gases were high and that in 87 there were some rules enacted. Thus this is a plausible explanation for the decreased in 89.

Compare this to B and you will see Process of elimination working here. E makes more sense than B.

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Re: 1000 CR test - 16 [#permalink]

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03 May 2010, 11:53
my pick is (B). what is the OA?

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Re: 1000 CR test - 16 [#permalink]

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03 May 2010, 13:45
sushantdsahu 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.

Going with "B". NEw more accurate device was invented does not imply it was used.
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Re: 1000 CR test - 16   [#permalink] 03 May 2010, 13:45
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