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

It is currently 30 Jul 2014, 23:26

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

Manatees, aquatic mammals inhabiting Florida s rivers and

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
VP
VP
User avatar
Joined: 01 Oct 2013
Posts: 1468
Followers: 208

Kudos [?]: 44 [0], given: 0

Premium Member
Re: Manatees, aquatic mammals inhabiting Florida s rivers and [#permalink] New post 27 Nov 2013, 02:39
Hello from the GMAT Club VerbalBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
Kaplan Promo CodeKnewton GMAT Discount CodesVeritas Prep GMAT Discount Codes
Director
Director
avatar
Joined: 29 Nov 2012
Posts: 930
Followers: 11

Kudos [?]: 234 [0], given: 543

Re: Manatees, aquatic mammals [#permalink] New post 27 Nov 2013, 02:39
krypt wrote:
I think the answer is E.

The hypothesis is that boats traveling slow = less manatees killed. However, manatees can't hear slow boats and therefore, slow boats will make the problem WORSE. The argument is saying that boats traveling at various speeds will kill less manatees than all boats traveling slowly on the account that manatees can't hear slow boats.

To cast doubt on this, we can show that manatees can't hear various speeds. Thus, mandating slow boats will not make the problem WORSE, it should stay the same.


Great explanation! very helpful
_________________

Click +1 Kudos if my post helped...

Amazing Free video explanation for all Quant questions from OG 13 and much more http://www.gmatquantum.com/og13th/

GMAT Prep software What if scenarios gmat-prep-software-analysis-and-what-if-scenarios-146146.html

Manager
Manager
avatar
Joined: 31 Mar 2013
Posts: 70
Followers: 0

Kudos [?]: 9 [0], given: 94

CAT Tests
Re: Manatees, aquatic mammals inhabiting Florida s rivers and [#permalink] New post 28 Nov 2013, 20:23
Manatees, aquatic mammals inhabiting Florida’s rivers and coastal waters, swim close to the surface and are frequently killed in collisions with boats. To address the problem, boat traffic in manatee-populated waters is being required to maintain very low speeds. Unfortunately, manatees are unable to hear low-pitched sounds and a boat’s sound lowers in pitch as the boat slows. Therefore, this approach may in fact make things worse rather than better.

Which of the following, if true, casts most doubt on the conclusion?

A. The areas where boats would have to maintain low speeds were decided partly on
the basis of manatee-population estimates and partly from numbers of reported
collisions between manatees and boats.
B. Because the water hyacinth that manatees feed on grows best in water that is
nearly still, water hyacinth beds can be disturbed or damaged by fast-moving boat
traffic.
C. Over the last several decades, boat traffic in Florida’s coastal waters has been
increasing almost continuously and now represents the greatest threat to the
endangered manatee population.
D. The sound of a boat engine generally travels much further under water than it
does through the air.
E. When experimenters exposed manatees to the recorded sounds of boats moving at
various speeds, the creatures were unable to discern the sounds over normal
background noise.

I marked the OA by PoE, but I was not much clear on the argument. Can someone explain on the argument and answer choice?

Can someone please explain this. I still dont understand why E is correct.

Premise: Manatees swim near the surface and get killed. To solve this problem, even low speed boats are not of much use because the Manatees cannot hear the low pitch sound of the boats.
Conclusion: The above approach may actually result in more Manatees getting killed.

To weaken the conclusion, we have to find an option where more Manatees are NOT getting killed, right?

Option E states that Manatees cannot distinguish low pitch sounds, so this will actually result in more Manatees getting killed. This seems to strengthen the conclusion. Can the experts help me on this?
Manager
Manager
avatar
Joined: 09 Apr 2013
Posts: 140
Location: India
WE: Supply Chain Management (Consulting)
Followers: 1

Kudos [?]: 26 [0], given: 18

Re: Manatees, aquatic mammals inhabiting Florida s rivers and [#permalink] New post 29 Nov 2013, 03:07
Agree. E is the answer.

D is a trap answer.

The sound of a boat engine generally travels much further under water than it
does through the air.


It says that sound travels much further under water than it does through air. The choice is more generic and does not say anything about the manatees' hearing capacity.
_________________

+1 KUDOS is the best way to say thanks :-)

"Those, who never do any more than they get paid for, never get paid for any more than they do"

Manager
Manager
User avatar
Joined: 15 Sep 2011
Posts: 182
Location: United States
Concentration: Finance, International Business
WE: Corporate Finance (Manufacturing)
Followers: 1

Kudos [?]: 62 [0], given: 5

Re: Manatees, aquatic mammals inhabiting Florida s rivers and [#permalink] New post 06 Feb 2014, 18:26
Conclusion: Therefore, this approach may in fact make things worse rather than better.

Reasoning: High boat speeds kills manatees. Slow boat speeds kills more manatees because manatees cannot hear any sound. To weaken the argument, the statement must provide that slow boat speeds do not kill any more than high boat speeds. (Wrong answers are neutral or provide reasons why slow boat speeds do kill more manatees than high boat speeds.)

A. The areas where boats would have to maintain low speeds were decided partly on the basis of manatee-population estimates and partly from numbers of reported
collisions between manatees and boats. Neutral. Statement does not cast doubt.

B. Because the water hyacinth that manatees feed on grows best in water that is nearly still, water hyacinth beds can be disturbed or damaged by fast-moving boat
traffic.Wrong. Statement provides a reason why more manatees are present in waters with slow boat speeds.

C. Over the last several decades, boat traffic in Florida’s coastal waters has been increasing almost continuously and now represents the greatest threat to the
endangered manatee population. Neutral. More boats kill more manatees; nothing about boat speeds.

D. The sound of a boat engine generally travels much further under water than it does through the air. Opposite answer - admittedly, this one threw me off. I forgot if this question were a strengthen or weaken, and key words such as "engine" + "travel much further" made a good trap. Brain fail.

E. When experimenters exposed manatees to the recorded sounds of boats moving at various speeds, the creatures were unable to discern the sounds over normal
background noise. OK - that slow boat speeds do not kill any more than high boat speeds.
_________________

A little kudos never hurt anyone. :)

Manager
Manager
avatar
Joined: 25 Oct 2013
Posts: 173
Followers: 0

Kudos [?]: 22 [0], given: 56

Re: Manatees, aquatic mammals inhabiting Florida s rivers and [#permalink] New post 07 Feb 2014, 06:22
+1 E

The conclusion here is that slow boats emit lower pitch sounds and since manatee are unable to hear low pitch sounds, the situation can become worst with slow boats. The hearing ability of manatees is what the conclusion depends on, and must be targeted.

E clearly shows that sound hardly plays any role in alertness of manatee. hence it weakens the conclusion.

D is tempting, but it fails to explain why manatees collide with faster moving boats. faster boats emit higher pitch sounds and should in fact alert the manatees.
_________________

Click on Kudos if you liked the post!

Practice makes Perfect.

Manager
Manager
avatar
Status: Squeezing the last few ounces
Joined: 14 Feb 2013
Posts: 55
Location: United States (MI)
Concentration: General Management, Technology
GMAT Date: 04-24-2013
GPA: 3.5
WE: Information Technology (Computer Software)
Followers: 0

Kudos [?]: 22 [0], given: 13

Re: Manatees, aquatic mammals inhabiting Florida s rivers and [#permalink] New post 07 Feb 2014, 07:06
mejia401 wrote:
Conclusion: Therefore, this approach may in fact make things worse rather than better.

Reasoning: High boat speeds kills manatees. Slow boat speeds kills more manatees because manatees cannot hear any sound. To weaken the argument, the statement must provide that slow boat speeds do not kill any more than high boat speeds. (Wrong answers are neutral or provide reasons why slow boat speeds do kill more manatees than high boat speeds.)

A. The areas where boats would have to maintain low speeds were decided partly on the basis of manatee-population estimates and partly from numbers of reported
collisions between manatees and boats. Neutral. Statement does not cast doubt.

B. Because the water hyacinth that manatees feed on grows best in water that is nearly still, water hyacinth beds can be disturbed or damaged by fast-moving boat
traffic.Wrong. Statement provides a reason why more manatees are present in waters with slow boat speeds.

C. Over the last several decades, boat traffic in Florida’s coastal waters has been increasing almost continuously and now represents the greatest threat to the
endangered manatee population. Neutral. More boats kill more manatees; nothing about boat speeds.

D. The sound of a boat engine generally travels much further under water than it does through the air. Opposite answer - admittedly, this one threw me off. I forgot if this question were a strengthen or weaken, and key words such as "engine" + "travel much further" made a good trap. Brain fail.

E. When experimenters exposed manatees to the recorded sounds of boats moving at various speeds, the creatures were unable to discern the sounds over normal
background noise. OK - that slow boat speeds do not kill any more than high boat speeds.



So you are saying that sound is the only thing that can kill manatees. If I am hit by a ball at 5 mph it might sting a little but if I am hit by the same ball at 50 mpg I might die. Basic physics 101
_________________

Life is a highway
I wanna ride it all night long

Manager
Manager
User avatar
Joined: 10 Mar 2013
Posts: 178
Followers: 0

Kudos [?]: 5 [0], given: 1297

CAT Tests
Re: Manatees, aquatic mammals inhabiting Florida s rivers and [#permalink] New post 31 May 2014, 16:34
Re: Manatees, aquatic mammals inhabiting Florida s rivers and   [#permalink] 31 May 2014, 16:34
    Similar topics Author Replies Last post
Similar
Topics:
1 Manatees, aquatic mammals inhabiting Florida s rivers and reply2spg 7 19 Feb 2009, 09:45
Manatees, aquatic mammals inhabiting Florida s rivers and prasannar 10 27 Apr 2008, 11:05
Manatees, aquatic mammals inhabiting Florida s rivers and younggun044 7 06 Oct 2007, 18:46
Manatees, aquatic mammals inhabiting Florida s rivers and Jamesk486 6 01 Jun 2007, 08:48
Manatees, aquatic mammals inhabiting Florida s rivers and ttanvir 4 11 Dec 2006, 16:06
Display posts from previous: Sort by

Manatees, aquatic mammals inhabiting Florida s rivers and

  Question banks Downloads My Bookmarks Reviews Important topics  

Go to page   Previous    1   2   [ 28 posts ] 



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®.