In 1986, the city of Los Diablos had 20 days on which air : GMAT Critical Reasoning (CR)
Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 27 Feb 2017, 15:39

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

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

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
TAGS:

### Hide Tags

Intern
Joined: 07 Apr 2010
Posts: 11
Followers: 0

Kudos [?]: 2 [0], given: 1

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

### Show Tags

28 Apr 2010, 13:52
00:00

Difficulty:

(N/A)

Question Stats:

60% (01:46) correct 40% (01:53) wrong based on 10 sessions

### HideShow timer Statistics

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.

Please answer the above question with explanation.
_________________

-Supply Chain Management

If you have any questions
you can ask an expert
New!
Senior Manager
Joined: 21 Mar 2010
Posts: 314
Followers: 5

Kudos [?]: 30 [0], given: 33

Re: 1000 CR test - 16 [#permalink]

### Show Tags

28 Apr 2010, 14:20
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.

Please answer the above question with explanation.

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.
Intern
Joined: 07 Apr 2010
Posts: 11
Followers: 0

Kudos [?]: 2 [0], given: 1

Re: 1000 CR test - 16 [#permalink]

### Show Tags

28 Apr 2010, 15:09
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.

Please answer the above question with explanation.

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.
_________________

-Supply Chain Management

Director
Joined: 24 Aug 2007
Posts: 954
WE 1: 3.5 yrs IT
WE 2: 2.5 yrs Retail chain
Followers: 77

Kudos [?]: 1277 [0], given: 40

Re: 1000 CR test - 16 [#permalink]

### Show Tags

29 Apr 2010, 00:42
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.

Please answer the above question with explanation.

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.]

_________________

Tricky Quant problems: http://gmatclub.com/forum/50-tricky-questions-92834.html
Important Grammer Fundamentals: http://gmatclub.com/forum/key-fundamentals-of-grammer-our-crucial-learnings-on-sc-93659.html

Manager
Joined: 28 Aug 2009
Posts: 196
Followers: 2

Kudos [?]: 79 [0], given: 1

Re: 1000 CR test - 16 [#permalink]

### Show Tags

29 Apr 2010, 04:13
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...
Senior Manager
Joined: 21 Mar 2010
Posts: 314
Followers: 5

Kudos [?]: 30 [0], given: 33

Re: 1000 CR test - 16 [#permalink]

### Show Tags

29 Apr 2010, 07:57
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.

Please answer the above question with explanation.

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.
Director
Joined: 24 Aug 2007
Posts: 954
WE 1: 3.5 yrs IT
WE 2: 2.5 yrs Retail chain
Followers: 77

Kudos [?]: 1277 [0], given: 40

Re: 1000 CR test - 16 [#permalink]

### Show Tags

29 Apr 2010, 08:41
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.
_________________

Tricky Quant problems: http://gmatclub.com/forum/50-tricky-questions-92834.html
Important Grammer Fundamentals: http://gmatclub.com/forum/key-fundamentals-of-grammer-our-crucial-learnings-on-sc-93659.html

Senior Manager
Joined: 21 Mar 2010
Posts: 314
Followers: 5

Kudos [?]: 30 [0], given: 33

Re: 1000 CR test - 16 [#permalink]

### Show Tags

29 Apr 2010, 10:21
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.
SVP
Joined: 17 Feb 2010
Posts: 1558
Followers: 19

Kudos [?]: 597 [0], given: 6

Re: 1000 CR test - 16 [#permalink]

### Show Tags

03 May 2010, 10:53
my pick is (B). what is the OA?
Intern
Joined: 14 Mar 2010
Posts: 39
Location: Lexington, KY
WE 1: 6 years in IT
Followers: 0

Kudos [?]: 3 [0], given: 1

Re: 1000 CR test - 16 [#permalink]

### Show Tags

03 May 2010, 12:45
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.

Please answer the above question with explanation.

Going with "B". NEw more accurate device was invented does not imply it was used.
_________________

To reach a port, we must sail—Sail, not tie at anchor—Sail, not drift.

Re: 1000 CR test - 16   [#permalink] 03 May 2010, 12:45
Similar topics Replies Last post
Similar
Topics:
In 1986, the city of Los Diablos had 20 days on which air 2 22 Feb 2008, 18:17
1986, the city of Los Diablos had 20 days on which air 9 10 Dec 2007, 16:07
In 1986, the city of Los Diablos had 20 days on which air 5 30 Oct 2007, 11:44
In 1986, the city of Los Diablos had 20 days on which air 7 26 Jul 2007, 22:13
In 1986, the city of Los Diablos had 20 days on which air 17 07 Jun 2007, 21:23
Display posts from previous: Sort by

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

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics

 Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.