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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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02 Sep 2011, 09:05
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16% (01:19) correct 84% (01:52) wrong based on 42 sessions

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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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02 Sep 2011, 09:22
Looks B to me

The reason is that option B says the Spectometer is invented !
It doesnt say that it is used!

Whats the OA ??
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02 Sep 2011, 10:52
I vote D, and my reasoning is that you have ozone levels consistently increasing each year, then dropping off the last year. So you got a crooked Mayor who is taking bribes, etc so he wont include the big polluters in their ozone studies. That alone should keep the ozone measures down in the city since you arent counting them, yet the levels still increase for 2 yrs in a row. ( hmm, that's odd) ,, so then the mayor gets busted in 1988 and the very next year, you would think ok, now these big polluters can't buy their way out of this mess and they will be included in the study, so therefore , the city will show huge increases in ozone levels bc you are now counting all these big polluters for the first time. well, in 1989 the ozone levels drop ( hmm, that's odd too). so that is why this answer choice '' least'' explains anything to me.

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Re: CR-City of Los Diablos [#permalink]

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03 Sep 2011, 09:21
+1 for D

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Re: CR-City of Los Diablos [#permalink]

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03 Sep 2011, 11:06
bholakc 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.

1986: 20 alarms
1987: Law enacted; 31 alarms
1988: 39 alarms
1989: 16 alarms

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?

Q: What would be least helpful to determine alarm increase between 1986-1989. One would think:
--why even after the law enactment, there was an increase in the number of alarm between 1986-1988 and then sudden fall in 1989.

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
Good reason. Because the law was not put into effect until almost 1989, the polluters had had the luxury to exploit the atmosphere to a greater degree until then.

(B) In December of 1988 a new and far more accurate gas spectrometer was invented.
A less accurate spectrometer could be the reason for generating unwarranted alarms. The new more accurate spectrometer might have generated fewer alarms in 1989. We need to make subtle assumptions in each of these crossed items.

(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.
The assumption is that the scale was made more lenient than stricter.
e.g. between 1986-1988, the alarm would raise if the pollution is more than 1mg/ft^3
e.g. in 1989, the alarm would raise if the pollution is more than 2mg/ft^3

(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.

Firstly, this statement creates a paradox why, despite these exemptions, the number of alarms went down in 1989. After all, these industries would have gotten the exemption only to freely pollute the air, right? However, we can ignore that aspect because question is focused on the increased alarm before 1989; alright.
Secondly, and this answers our question, it leaves the question in hand untouched: when the exemptions were given to these industries only in 1988, they must had been following the law until 1988. So, what on earth actually caused those increased alarms.
No clue!!!
Correct.

(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.
Well!! This doesn't clearly explain the increase between 1987 and 1988, while it does explain a decrease in 1989. We can assume that breaking down process is not gradual but sporadic.

Ans: "D"
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Re: CR-City of Los Diablos [#permalink]

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03 Sep 2011, 13:53
fluke wrote:
bholakc 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.

1986: 20 alarms
1987: Law enacted; 31 alarms
1988: 39 alarms
1989: 16 alarms

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?

Q: What would be least helpful to determine alarm increase between 1986-1989. One would think:
--why even after the law enactment, there was an increase in the number of alarm between 1986-1988 and then sudden fall in 1989.

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
Good reason. Because the law was not put into effect until almost 1989, the polluters had had the luxury to exploit the atmosphere to a greater degree until then.

(B) In December of 1988 a new and far more accurate gas spectrometer was invented.
A less accurate spectrometer could be the reason for generating unwarranted alarms. The new more accurate spectrometer might have generated fewer alarms in 1989. We need to make subtle assumptions in each of these crossed items.

(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.
The assumption is that the scale was made more lenient than stricter.
e.g. between 1986-1988, the alarm would raise if the pollution is more than 1mg/ft^3
e.g. in 1989, the alarm would raise if the pollution is more than 2mg/ft^3

(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.

Firstly, this statement creates a paradox why, despite these exemptions, the number of alarms went down in 1989. After all, these industries would have gotten the exemption only to freely pollute the air, right? However, we can ignore that aspect because question is focused on the increased alarm before 1989; alright.
Secondly, and this answers our question, it leaves the question in hand untouched: when the exemptions were given to these industries only in 1988, they must had been following the law until 1988. So, what on earth actually caused those increased alarms.
No clue!!!
Correct.

(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.
Well!! This doesn't clearly explain the increase between 1987 and 1988, while it does explain a decrease in 1989. We can assume that breaking down process is not gradual but sporadic.

Ans: "D"

D

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Re: CR-City of Los Diablos [#permalink]

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05 Oct 2011, 02:25
went for B until I read this explanation. Thanks, fluke!

fluke wrote:
bholakc 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.

1986: 20 alarms
1987: Law enacted; 31 alarms
1988: 39 alarms
1989: 16 alarms

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?

Q: What would be least helpful to determine alarm increase between 1986-1989. One would think:
--why even after the law enactment, there was an increase in the number of alarm between 1986-1988 and then sudden fall in 1989.

(A) The 1987 air pollution control measures enacted in Los Diablos were put into effect in November of 1988.
Good reason. Because the law was not put into effect until almost 1989, the polluters had had the luxury to exploit the atmosphere to a greater degree until then.

(B) In December of 1988 a new and far more accurate gas spectrometer was invented.
A less accurate spectrometer could be the reason for generating unwarranted alarms. The new more accurate spectrometer might have generated fewer alarms in 1989. We need to make subtle assumptions in each of these crossed items.

(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.
The assumption is that the scale was made more lenient than stricter.
e.g. between 1986-1988, the alarm would raise if the pollution is more than 1mg/ft^3
e.g. in 1989, the alarm would raise if the pollution is more than 2mg/ft^3

(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.

Firstly, this statement creates a paradox why, despite these exemptions, the number of alarms went down in 1989. After all, these industries would have gotten the exemption only to freely pollute the air, right? However, we can ignore that aspect because question is focused on the increased alarm before 1989; alright.
Secondly, and this answers our question, it leaves the question in hand untouched: when the exemptions were given to these industries only in 1988, they must had been following the law until 1988. So, what on earth actually caused those increased alarms.
No clue!!!
Correct.

(E) Excess ozone and carbon monoxide require a minimum of two years to break down naturally in the atmosphere above a given area.
Well!! This doesn't clearly explain the increase between 1987 and 1988, while it does explain a decrease in 1989. We can assume that breaking down process is not gradual but sporadic.

Ans: "D"

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Re: CR-City of Los Diablos [#permalink]

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05 Oct 2011, 07:33
D...

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Re: CR-City of Los Diablos [#permalink]

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07 Oct 2011, 02:56
fluke wrote:
bholakc wrote:

(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.

Firstly, this statement creates a paradox why, despite these exemptions, the number of alarms went down in 1989. After all, these industries would have gotten the exemption only to freely pollute the air, right? However, we can ignore that aspect because question is focused on the increased alarm before 1989; alright.
Secondly, and this answers our question, it leaves the question in hand untouched: when the exemptions were given to these industries only in 1988, they must had been following the law until 1988. So, what on earth actually caused those increased alarms.
No clue!!!
Correct.

Ans: "D"

Fluke,

The question specifically looks for an explanation for the pollution levels between the period 1986 to 1989. Therefore we have to explain the pollution in 1987 and 1988. 1988 saw a peak in the pollution, can this not be explained by the malfeasance of the mayor in 1988?

I agree that this does not explain the drop in 1989. But should we be trying to explain that in the first place? The question does not seem to ask for that.

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Re: CR-City of Los Diablos [#permalink]

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07 Oct 2011, 03:55
DexDee wrote:
Fluke,

The question specifically looks for an explanation for the pollution levels between the period 1986 to 1989. Therefore we have to explain the pollution in 1987 and 1988. 1988 saw a peak in the pollution, can this not be explained by the malfeasance of the mayor in 1988?

I agree that this does not explain the drop in 1989. But should we be trying to explain that in the first place? The question does not seem to ask for that.

"D" just explains why alarms went up from 31 in 1987 to 39 in 1988. But, the explanation won't be considered justified because again the alarm dropped to 16 in 1989. Also, it doesn't explain why the alarm went up to 31 in 1987 from 20 in 1986, when ideally it should have gone down. You see "D" gives us a perfect reason for the increase between 1987 and 1988, but that explanation will be considered inconsistent with the alarm statistics for other years.

"But should we be trying to explain that in the first place?"
would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989?
I believe the question wants us to consider everything between 1986 and 1989.
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Re: CR-City of Los Diablos [#permalink]

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10 Oct 2011, 02:57
I go for B.

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Re: CR-City of Los Diablos [#permalink]

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18 Oct 2011, 05:04
D for me !!

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Re: CR-City of Los Diablos   [#permalink] 18 Oct 2011, 05:04
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