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

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22 Aug 2012, 21:18
siddharthasingh 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.

Here's my take

A - Once put into effect in Nov 1988, the measures can show effect in 1989. Therefore, this option helps explain.

C - Once again helps explain

E - Helps explain

Leaves us with B and D.

Both of which seem to not explain.

B - Invention does not necessarily mean adoption. A more accurate spectrometer was invented but that does not mean that the city actually used this. We don't know if it used this or not.

D - Similarly this option talks about mayor taking donations and exempting the industries in the following year from those measures. Why would industries be exempted from pollution controls if they did not pollute ?? (Beats logic). And the same year when the pollution went up? It seems to explain to me.

So B seems to be the answer.

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23 Aug 2012, 00:38
mvikred wrote:
siddharthasingh 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.

Here's my take

A - Once put into effect in Nov 1988, the measures can show effect in 1989. Therefore, this option helps explain.

C - Once again helps explain

E - Helps explain

Leaves us with B and D.

Both of which seem to not explain.

B - Invention does not necessarily mean adoption. A more accurate spectrometer was invented but that does not mean that the city actually used this. We don't know if it used this or not.

D - Similarly this option talks about mayor taking donations and exempting the industries in the following year from those measures. Why would industries be exempted from pollution controls if they did not pollute ?? (Beats logic). And the same year when the pollution went up? It seems to explain to me.

So B seems to be the answer.

Just to add to above points for option D: It does not explain what happens post 1988. Was expemtion removed? There is no mention of this assumption. Also it does not state since when was exemption given. Was exemption applicable in 1986 and 1987?

So per me b/w b and D , D option has an edge.
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23 Aug 2012, 01:16
how come d has an edge. As mentioned earlier, adaption of a machine and machine inventing a machine are two very different things.
The key point is the reason everyone is eliminating D because they are assuming that these local industries were the ones that caused pollution.
I am not getting it.
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Re: City of Los Diablos [#permalink]

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29 Aug 2012, 10:37
sk818020 wrote:
Quote:
why cant you assume that the old meter was probably showing the wrong results

The reason you can't assume this is because the passage doesn't give us any information indicating this is a safe assumption. Again, we are basing our reasoning only on what is in the passage, regardless of what would seem to be the case in the real world or based on common sense.

The passage only states that the pollutants were monitored by a gas spectrometer. It does not say that a new gas spectrometer will cause there to be more or less alert days. It could cause more, it could cause less. Based on the passage we don't know.

Thanks,

Jared

Hi guys,

Thanks for the explanation above.

But just to add, I feel B states that new instrument was INVENTED, as per the question we must believe it was invented but we can not assume that the same instrument was installed or used.

Hope my reasoning is right.

Thanks,

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

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29 Aug 2012, 11:22
spectrometer is nowhere mentioned in the argument
so replacing it with any other instrument is same
correct me if i am wrong

i mean what does a time machine got to do with increase or decrease in pollution
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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18 Nov 2012, 22:28
i will go with option 'b' ,inventing an equipment does not mean helpful in explaining pollution levels.
coming to 'd'-if industries are exempted from pollution laws,it will effect the pollution levels.
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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18 Nov 2012, 22:32
i will go with option 'b' ,inventing an equipment does not mean helpful in explaining pollution levels.
coming to 'd'-if industries are exempted from pollution laws,it will effect the pollution levels.
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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19 Nov 2012, 02:38

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

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22 Jan 2013, 11:03
My reasoning went like this: what do I need to know in order to understand why the pollution apparently dropped?
It could have happened really and I need a a device to test it, or the pollution could have stopped being monitored appropriately.

Either way a new and more accurate device does not help me (B) because even if it is used, wich I am not sure of, and it is registering lower levels, I still do not know why the levels are lower.
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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22 Jan 2013, 12:18
I agree with IanStewart and others: Bad question; don't study it. Choice (B) can help explain it: If a more accurate meter was invented, the city COULD have started using it at the end of 1988, and the old meter COULD have been overestimating, and then the more accurate readings of the new meter would explain the lower numbers in 1989. But (D) can also help explain it, depending on WHEN the mayor allowed the companies to be exempted. If that happened back in 1987, it would explain why pollution went up in spite of the regulations. On the other hand, if the mayor just recently allowed those exemptions, we would expect 1989 to suffer the effects of it. Since (D) doesn't tell us when the companies benefited from the exemption, it is not clear whether it helps to explain the discrepancies or not.
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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24 Jan 2013, 15:45
Took me two minutes but B is correct. Tricky, Tricky, Tricky.

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

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14 Mar 2013, 06:41
still not quite convinced with B
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Re: In 1986, the city of Los Diablos had 20 days on which air [#permalink]

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14 Mar 2013, 07:30
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TheNona wrote:
still not quite convinced with B

Hi TheNona,

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 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.

Hope this helps,

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

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14 Mar 2013, 09:41
I selected D but looks like the correct answer is B.

Logic: Newly invented Spectrometer does not bother the level of pollution in Los Diablos

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

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17 Mar 2013, 21:29
Reason the answer is not D is : option says 1988 Industries were exempted which means those industries will create more pollution and that explains sudden high level of pollution ( 39 days in 1988) , so this helps in explaining and not the right answer

B tells that more accurate device was invented which means more number of days could be of smog alert in 1989 but thats not true so it doesn't help in explaining

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

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20 Mar 2013, 03:46
Vercules wrote:
TheNona wrote:
still not quite convinced with B

Hi TheNona,

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 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.

Hope this helps,

Vercules

Vercules,
B) says that a new and accurate device was invented in 1989.
My questions are
1) did the city use it in 1989
2) whether old device that had been used was inaccurate?

I believe B) and D) are equally poised in the second level of usage.
1986 - 88 - Old device - inaccurate
89 - new device - accurate.

Can we debate on this ? Pl explain.

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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.
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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
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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] 28 Apr 2013, 15:41

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