Find all School-related info fast with the new School-Specific MBA Forum

It is currently 26 Jul 2014, 05:25

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Since 1985, pollution levels in Lake Thomas have dropped

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
CEO
CEO
avatar
Joined: 15 Aug 2003
Posts: 3470
Followers: 59

Kudos [?]: 658 [0], given: 781

Since 1985, pollution levels in Lake Thomas have dropped [#permalink] New post 25 Sep 2003, 16:46
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

36% (02:32) correct 64% (01:15) wrong based on 12 sessions
Since 1985, pollution levels in Lake Thomas have dropped considerably, primarily because of a state program to clean the lake water by means of a water refinery. Ironically, during this same period, the once-abundant population of sunfish in the lake has dwindled.

Which of the following, if true, would best explain why the sunfish population of Lake Thomas has dwindled at the same time that the lake water has become cleaner?


The life spans of sunfish are not diminished by high pollution levels, but the number of offspring they create during their lifetime is diminished.

Several artificial chemicals are introduced into the lake as a result of the refinement process, but these chemicals are known to have a benign effect on fish.

The water refinement process creates an environment extremely favorable to pike, a predator fish.

The heaviest concentrations of sunfish population in the lake are at its northern and northeastern shores, many miles away from the water refinery.

Ever since 1972, a strictly enforced state regulation has prevented anglers from over-fishing Lake Thomas.
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1614
Followers: 5

Kudos [?]: 38 [0], given: 0

 [#permalink] New post 25 Sep 2003, 21:24
I vote for A. The refinement has nothing to do with dwindling the sunfish population. It is previous pollutants that prevent the sunfish from breeding, and the effect of pollution simply concides with the time of refinement.

C is temptive, but we do not know for sure whether the pike preys on the sunfish. In fact, the reverse situation is possible.
Manager
Manager
avatar
Joined: 13 Aug 2003
Posts: 68
Location: India
Followers: 1

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

 [#permalink] New post 25 Sep 2003, 21:32
stolyar it cant be A as the population has dwindled only since the new process was put in place... so C has to be right ...
Manager
Manager
avatar
Joined: 13 Aug 2003
Posts: 68
Location: India
Followers: 1

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

 [#permalink] New post 25 Sep 2003, 21:42
on second thots A is right stoylar.. I reread it... as the offsprings havre reduced and the most of the fish would have died in this span. so very few remain.
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1614
Followers: 5

Kudos [?]: 38 [0], given: 0

 [#permalink] New post 25 Sep 2003, 21:42
C has to be right assuming that the pike preys on the sunfish. But is this assumption valid? I think not.

The right C should be: The water refinement process creates an environment extremely favorable to the pike, a predator fish praying on the sunfish.

As for A: the sunfish population was abundant but did not have enough offsprings. The old fish start to die; the number of the young fish is small, and even clean water cannot correct the situation.
Manager
Manager
avatar
Joined: 13 Aug 2003
Posts: 68
Location: India
Followers: 1

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

 [#permalink] New post 25 Sep 2003, 21:46
A small catch here mate.. what if the average fish lives for a span exceeding the period ; )then all must be alive.. so the fish dying is also an assumption ; )
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1614
Followers: 5

Kudos [?]: 38 [0], given: 0

 [#permalink] New post 25 Sep 2003, 21:51
I thought about it. The CR sections requires that we take the best answer. I hope A is the best, simply the best, as Tina Turner sings. Let's wait for the official answer.
GMAT Instructor
User avatar
Joined: 07 Jul 2003
Posts: 771
Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE
Followers: 9

Kudos [?]: 25 [0], given: 0

GMAT Tests User
Re: CR : Pollution [#permalink] New post 26 Sep 2003, 00:35
praetorian123 wrote:
Simple one, but got it wrong!

Since 1985, pollution levels in Lake Thomas have dropped considerably, primarily because of a state program to clean the lake water by means of a water refinery. Ironically, during this same period, the once-abundant population of sunfish in the lake has dwindled.

Which of the following, if true, would best explain why the sunfish population of Lake Thomas has dwindled at the same time that the lake water has become cleaner?


The life spans of sunfish are not diminished by high pollution levels, but the number of offspring they create during their lifetime is diminished.

Several artificial chemicals are introduced into the lake as a result of the refinement process, but these chemicals are known to have a benign effect on fish.

The water refinement process creates an environment extremely favorable to pike, a predator fish.

The heaviest concentrations of sunfish population in the lake are at its northern and northeastern shores, many miles away from the water refinery.

Ever since 1972, a strictly enforced state regulation has prevented anglers from over-fishing Lake Thomas.


My choice is definitely C.

Remember, we are trying to explain the decrease in Sunfish...

(A) states that number of offspring is DIMINISHED by pollution. Hence, if we REDUCE pollution, offspring will no longer be diminished. This certainly does not explain the decrease in Sunfish -- more likely it inplies that an eventually increase will occur.

(B) states that the chemical do not harm fish. Hence, this does not explain the decrease in Sunfish.

(C) states that a predatory fish thrives in the environment created by the refinery. Nitpicking aside, since the subject of the argument is the "sunfish", it is reasonable to assume that the term "predatory" refers to the relationship of the pike to the sunfish. This would certanly explain a decrease in sunfish and IMO is the best choice.

(D). states that the heaviest concentration of pike are far away from the refinery. While this is consistent with (C), it does not in itself explain an overall decrease in the sunfish population.

(E) does nothing to explain the decrease in Sunfish since 1985 and is irrelavent. In fact, it removes a possible explaination for the decrease.
_________________

Best,

AkamaiBrah
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993

Senior Manager
Senior Manager
avatar
Joined: 21 Aug 2003
Posts: 258
Location: Bangalore
Followers: 1

Kudos [?]: 4 [0], given: 0

GMAT Tests User
 [#permalink] New post 26 Sep 2003, 08:27
My vote: C
agree with akamaibrah...
CEO
CEO
avatar
Joined: 15 Aug 2003
Posts: 3470
Followers: 59

Kudos [?]: 658 [0], given: 781

Re: CR : Pollution [#permalink] New post 26 Sep 2003, 09:38
AkamaiBrah wrote:
praetorian123 wrote:
Simple one, but got it wrong!

Since 1985, pollution levels in Lake Thomas have dropped considerably, primarily because of a state program to clean the lake water by means of a water refinery. Ironically, during this same period, the once-abundant population of sunfish in the lake has dwindled.

Which of the following, if true, would best explain why the sunfish population of Lake Thomas has dwindled at the same time that the lake water has become cleaner?


The life spans of sunfish are not diminished by high pollution levels, but the number of offspring they create during their lifetime is diminished.

Several artificial chemicals are introduced into the lake as a result of the refinement process, but these chemicals are known to have a benign effect on fish.

The water refinement process creates an environment extremely favorable to pike, a predator fish.

The heaviest concentrations of sunfish population in the lake are at its northern and northeastern shores, many miles away from the water refinery.

Ever since 1972, a strictly enforced state regulation has prevented anglers from over-fishing Lake Thomas.


My choice is definitely C.

Remember, we are trying to explain the decrease in Sunfish...

(A) states that number of offspring is DIMINISHED by pollution. Hence, if we REDUCE pollution, offspring will no longer be diminished. This certainly does not explain the decrease in Sunfish -- more likely it inplies that an eventually increase will occur.

(B) states that the chemical do not harm fish. Hence, this does not explain the decrease in Sunfish.

(C) states that a predatory fish thrives in the environment created by the refinery. Nitpicking aside, since the subject of the argument is the "sunfish", it is reasonable to assume that the term "predatory" refers to the relationship of the pike to the sunfish. This would certanly explain a decrease in sunfish and IMO is the best choice.

(D). states that the heaviest concentration of pike are far away from the refinery. While this is consistent with (C), it does not in itself explain an overall decrease in the sunfish population.

(E) does nothing to explain the decrease in Sunfish since 1985 and is irrelavent. In fact, it removes a possible explaination for the decrease.



C is the correct answer

Thanks all for a good discussion
Praetorian
SVP
SVP
User avatar
Joined: 03 Feb 2003
Posts: 1614
Followers: 5

Kudos [?]: 38 [0], given: 0

 [#permalink] New post 26 Sep 2003, 10:01
I have an objection, but so be it.
CEO
CEO
avatar
Joined: 15 Aug 2003
Posts: 3470
Followers: 59

Kudos [?]: 658 [0], given: 781

 [#permalink] New post 26 Sep 2003, 12:18
stolyar wrote:
I have an objection, but so be it.


Stolyar, i totally understand the objection about C.

I picked A too,but Akamai's explanation makes sense....the pollution

levels are down, so there should not be any problems with the creation of

offspring. A doesnt help us get there...

I agree that C is way too general. but its the BEST ANSWER.

Thanks All
Praetorian
  [#permalink] 26 Sep 2003, 12:18
    Similar topics Author Replies Last post
Similar
Topics:
1 In a polluted area around the Great Lakes, scientists guerrero25 2 01 Jun 2013, 13:39
2 In a polluted area around the Great Lakes, scientists Aristocrat 7 29 Dec 2012, 23:01
2 In a polluted area around the Great Lakes, scientists shrive555 3 05 Oct 2010, 09:01
Since 1985, pollution levels in Lake Thomas have dropped Praetorian 11 17 Jul 2006, 11:48
At ground level, ozone is a harmful pollutant, but in the cool_jonny009 6 05 Jan 2006, 23:39
Display posts from previous: Sort by

Since 1985, pollution levels in Lake Thomas have dropped

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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®.