City of Los Diablos .....

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City of Los Diablos .....

by saurabh_maths » Wed Mar 02, 2011 6:56 pm
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.

OA is B.
But I am confused how B could be least helpful here. Infact it is helping in explaining the drop of smog alerts in 1989.
Can some one help .

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by Target2009 » Wed Mar 02, 2011 7:58 pm
My Pick : B
B talks about new device , which will be helpful if we are talking about accurecy.
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by makkiemaps » Wed Mar 02, 2011 8:06 pm
Target2009 wrote:My Pick : B
B talks about new device , which will be helpful if we are talking about accurecy.
Can you please explain?

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by Target2009 » Wed Mar 02, 2011 8:21 pm
makkiemaps wrote:
Target2009 wrote:My Pick : B
B talks about new device , which will be helpful if we are talking about accurecy.
Can you please explain?
Que is : would be LEAST helpful in explaining the air pollution levels in Los Diablos between 1986 and 1989

B is taking about : In December of 1988 a new and far more accurate gas spectrometer was invented.

New spectrometer has nothing to do with explaining the air pollution levels until argument doubting on mesurement accuracy of pollution level from 1986 to 1988.
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by ankurmit » Wed Mar 02, 2011 9:20 pm
I am confused between B and D.

But found D more convincing answer than B .

"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"

what if mayor exempt some industries from air pollution control measures the level of air pollution will be same.

Also the last line states that

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.

I dont think mayor exemption will have any effect on air pollution levels
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by bubbliiiiiiii » Wed Mar 02, 2011 11:00 pm
Do this kind of questions appear on GMAT? I am seeing it for the first time? !! :o
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by saurabh_maths » Thu Mar 03, 2011 4:58 pm
Even I chose D with the same reasoning as Ankur.

It looks to me that B infact helps us in explaning the air pollutiuon levels.
It says that a new better device was invented ..and which surely could explain the no. of smog alerts came down.

It could be possible that other device were not as accurate and thus even counting the smog level which is under the normal range as alerts. But due to this device, it was counted correctly and hence no. of alerts came down in 1989.


Can a expert pls thow some light??

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by fitzgerald23 » Thu Mar 03, 2011 8:31 pm
1. New Controls were put into effect in 1987 after significant pollution in 1986
2. Pollution still rose in 1987 and 1988 before falling in 1989

A. Incorrect. This is helpful since it tells us that there were no real controls in place until late in 1988.

B. Correct. Nowhere does this tell us that the city used this new invention. In addition what does it mean? Were old readings too high or were they too low?

C. Incorrect. The measuring scale being changed would certainly explain the drop in 1989.

D. Incorrect. If the mayor excluded certain places it would reason that the numbers would drop.

E. Incorrect. If it takes two years to break down then the rising readings were likely a byproduct of old smog and once they made their way out of the system the air cleared in 1989.

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by GMATMadeEasy » Fri Mar 04, 2011 8:14 am
@fitzgerald23 : I agree with you about B. However, for the option D, i also agree that number will drop in 1988 but the question says number went up to 39 in 1988. hence it does NOT explain the issue.

what do you say ? I may have missed something.

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by rohu27 » Sat Mar 05, 2011 12:23 am
fitzgerald one doubt here:

As per option D the actual levels should have dropped but they increased. So in no way it is helping to resolve the rise in leevls from 86 to 88. also it doesnt say anythgn abt why the levels in 87 increased.

i knw we need to select the option that LEAST talks abt the rise in levels, but im stuck here.

fitzgerald23 wrote:1. New Controls were put into effect in 1987 after significant pollution in 1986
2. Pollution still rose in 1987 and 1988 before falling in 1989

A. Incorrect. This is helpful since it tells us that there were no real controls in place until late in 1988.

B. Correct. Nowhere does this tell us that the city used this new invention. In addition what does it mean? Were old readings too high or were they too low?

C. Incorrect. The measuring scale being changed would certainly explain the drop in 1989.

D. Incorrect. If the mayor excluded certain places it would reason that the numbers would drop.

E. Incorrect. If it takes two years to break down then the rising readings were likely a byproduct of old smog and once they made their way out of the system the air cleared in 1989.

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by rohu27 » Sat Mar 05, 2011 12:24 am
Saurabh,
whts the source btw?
saurabh_maths 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.

OA is B.
But I am confused how B could be least helpful here. Infact it is helping in explaining the drop of smog alerts in 1989.
Can some one help .

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by rohu27 » Sat Mar 05, 2011 12:29 am
on a second thought ..
option D meant to say tht the while the mayor allowed industries to be exempt fmr the laws. when the values were measured obviously they would be included (as measuring the air pollution levels wudnt need any permisiion fmr indivdual industries, parties etc?)? is this the case?
thn it perfectly explains why there was rise in levels even after the laws were implemented.
but this is only for 88, what abt 87 then.