The Earth s rivers constantly carry dissolved salts into its : GMAT Critical Reasoning (CR) - Page 2
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 17 Jan 2017, 10:42

### 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

# The Earth s rivers constantly carry dissolved salts into its

Author Message
TAGS:

### Hide Tags

Intern
Joined: 05 Jul 2011
Posts: 14
Schools: Ohio State University
Followers: 0

Kudos [?]: 3 [0], given: 2

### Show Tags

20 Jul 2011, 01:38
bupbebeo wrote:
I believe E is correct answer

let's consider one thing in the stimulus. it says that we can calculate maximum age of the Earth's oceans, not age alone.

so, even A is true, we can still calculate maximum age of oceans because we still have the data of the salt in the ocean, which originates from rivers. In other words, the amount the rivers carry now in the oceans

but in E, it is very different, if we don't have data from the use of salts from biological activity in the oceans, so we don't know whether the amount rivers carry is all in the ocean. So how we can calculate the MAXIMUM AGE.

good point...very confused between A&E.....need an official explaination for this question...
Intern
Joined: 06 Jul 2011
Posts: 28
Followers: 0

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

### Show Tags

20 Jul 2011, 21:07
My original prediction before seeing the answers was that the rate by which salt was deposited in the last century must be representative of the centuries since the dawn of Earth.

But, since I'm still a careless noob at this point, I broke from my strategy and chose E.

Quote:
E. None of the salts carried into the Earth’s oceans by rivers are used up by biological activity in the oceans.

Remember, though, that we're looking only for an accurate estimate. So we don't need to be so bold (well, extreme) and assume none of the salts are used up by biological activity. They can. This is an estimate after all, right?

Quote:
A. The quantities of dissolved salts deposited by rivers in the Earth’s oceans have not been unusually large during the past hundred years.

Reading A again, I should have stuck with my prediction. For this argument, we must assume that the salt deposited wasn't unusually large during the last century. Else, we'd undershoot the age of the Earth -- certainly more than by a variance in our estimate of age due to biological activity. A is the correct answer IMO.
_________________

GMAT Day: Nov. 19, 2011

Manager
Joined: 05 Jul 2011
Posts: 68
Followers: 1

Kudos [?]: 73 [0], given: 14

### Show Tags

22 Jul 2011, 11:10
IMO A. Biological processes can be considered to have been taking place since the very beginning. Hence, the effect of bio act can be considered constant and thus it doesn't effect our calculation of Earth's age by the method suggested.
_________________

---Winners do it differently---

Retired Moderator
Status: 2000 posts! I don't know whether I should feel great or sad about it! LOL
Joined: 04 Oct 2009
Posts: 1712
Location: Peru
Schools: Harvard, Stanford, Wharton, MIT & HKS (Government)
WE 1: Economic research
WE 2: Banking
WE 3: Government: Foreign Trade and SMEs
Followers: 96

Kudos [?]: 909 [0], given: 109

### Show Tags

26 Jul 2011, 10:02
+1 A
_________________

"Life’s battle doesn’t always go to stronger or faster men; but sooner or later the man who wins is the one who thinks he can."

My Integrated Reasoning Logbook / Diary: http://gmatclub.com/forum/my-ir-logbook-diary-133264.html

GMAT Club Premium Membership - big benefits and savings

Manager
Joined: 24 Jun 2011
Posts: 58
Followers: 0

Kudos [?]: 9 [0], given: 6

### Show Tags

27 Jul 2011, 07:44
A For me

The method of estimating talks about prorating the salt increase in the last 100 years to an initial zero state.

If this method should work the value should be more or less closer to a constant increase over time.

Otherwise we would be over under-estimating the age of the earth.

A) says this is not the case and in the last century it is unusually high. Directly points out to a flaw in the method.
Manager
Joined: 26 Sep 2010
Posts: 114
GMAT 1: 680 Q49 V34
GPA: 3.65
Followers: 0

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

### Show Tags

07 Aug 2011, 02:16
"E" for me
GMAT Club Legend
Joined: 01 Oct 2013
Posts: 10528
Followers: 918

Kudos [?]: 203 [0], given: 0

Re: The Earth s rivers constantly carry dissolved salts into its [#permalink]

### Show Tags

19 Nov 2013, 03:55
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.
Intern
Status: Single
Affiliations: B.Tech
Joined: 03 Sep 2013
Posts: 6
WE: Analyst (Computer Software)
Followers: 0

Kudos [?]: 8 [0], given: 5

Re: The Earth s rivers constantly carry dissolved salts into its [#permalink]

### Show Tags

20 Nov 2013, 01:17
1
This post was
BOOKMARKED
A will be the correct answer .

E states that the salt is not being used by any biological activity . But , if we are to measure the age of the oceans this will not hamper that measurement as the quantity of salt, if being used by any biological activity would have been constant since the beginning . So , that constant will not affect the measurement .

A assumes that the quantity of salts deposited in recent hundred years is larger than other hundreds of years , thus the experiment will give an inconsistent answer .

Current Student
Joined: 03 Feb 2013
Posts: 939
Location: India
Concentration: Operations, Strategy
GMAT 1: 760 Q49 V44
GPA: 3.88
WE: Engineering (Computer Software)
Followers: 134

Kudos [?]: 838 [0], given: 546

Re: The Earth s rivers constantly carry dissolved salts into its [#permalink]

### Show Tags

25 Apr 2014, 10:53
lexis wrote:
The Earth’s rivers constantly carry dissolved salts into its oceans. Clearly, therefore, by taking the resulting increase in salt levels in the oceans over the past hundred years and then determining how many centuries of such increases it would have taken the oceans to reach current salt levels from a hypothetical initial salt-free state, the maximum age of the Earth’s oceans can be accurately estimated.

Which of the following is an assumption on which the argument depends?

A. The quantities of dissolved salts deposited by rivers in the Earth’s oceans have not been unusually large during the past hundred years.
B. At any given time, all the Earth’s rivers have about the same salt levels.
C. There are salts that leach into the Earth’s oceans directly from the ocean floor.
D. There is no method superior to that based on salt levels for estimating the maximum age of the Earth’s oceans.
E. None of the salts carried into the Earth’s oceans by rivers are used up by biological activity in the oceans.

Conclusion : By measuring the increase in salt over the past hundred years and by extrapolating the results, we can determine the maximum age of the Earth's Ocean.

Option A) Negation :
The quantities of dissolved salts deposited by rivers in the Earth’s oceans have been unusually large during the past hundred years.
More quantities of salt is added in the past 100 years, So if we extrapolate it over thousand of years, the years required will be lesser as compared to the actual age. That can impact the Maximum age calculation. Hence an assumption.

Option B) Doesn't matter as argument talks about the cumulative salt in the ocean.
Option C) Salt leach into the Earth's ocean from the floor. This would be captured the data for the last 100 years and it will be constant over the years. Hence it doesn't affect.
Option D) Out of scope.
Option E) Negation.
Some of the salts carried into the Earth’s oceans by rivers are used up by biological activity in the oceans.
In that case, this would be factored in the measurement done for the past 100 years and can be extrapolated over the thousands of years.

hence A)

BTW : It is from GMATPrep Question Pack 1.
_________________

Thanks,
Kinjal

My Application Experience : http://gmatclub.com/forum/hardwork-never-gets-unrewarded-for-ever-189267-40.html#p1516961
Prodigy for Tepper - CMU : http://bit.ly/cmuloan-kd

Re: The Earth s rivers constantly carry dissolved salts into its   [#permalink] 25 Apr 2014, 10:53

Go to page   Previous    1   2   [ 29 posts ]

Similar topics Replies Last post
Similar
Topics:
140 The Earth s rivers constantly carry dissolved salts into its 74 14 Aug 2008, 22:45
1 The Earth s rivers constantly carry dissolved salts into its 22 02 Apr 2008, 17:50
2 The Earth's rivers constantly carry dissolved salts into its 20 06 Jan 2008, 16:04
The Earth s rivers constantly carry dissolved salts into its 12 20 Dec 2007, 15:47
Q29: The Earth s rivers constantly carry dissolved salts 5 08 Jun 2007, 08:20
Display posts from previous: Sort by