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

 It is currently 16 Jan 2017, 03:58

### 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

Senior Manager
Joined: 07 Jan 2008
Posts: 412
Followers: 3

Kudos [?]: 215 [1] , given: 0

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

### Show Tags

19 Jun 2008, 10:44
1
KUDOS
1
This post was
BOOKMARKED
00:00

Difficulty:

(N/A)

Question Stats:

33% (02:31) correct 67% (01:14) wrong based on 44 sessions

### HideShow timer Statistics

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.
If you have any questions
New!
Senior Manager
Joined: 26 Mar 2008
Posts: 337
Location: Washington DC
Followers: 2

Kudos [?]: 76 [0], given: 4

### Show Tags

19 Jun 2008, 10:57
E for me. Though A is also close but between A and E, I would choose E.
Anyways good questions +1 to you, whats the source?
Manager
Joined: 21 Mar 2008
Posts: 244
Followers: 3

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

### Show Tags

19 Jun 2008, 12:11
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. - So....?
B. At any given time, all the Earth’s rivers have about the same salt levels. - Not a required assumption
C. There are salts that leach into the Earth’s oceans directly from the ocean floor. - Weakens
D. There is no method superior to that based on salt levels for estimating the maximum age of the Earth’s oceans. - We dont care
E. None of the salts carried into the Earth’s oceans by rivers are used up by biological activity in the oceans.

E.
The assumption is that whatever is carried stays and none is used and hence the correlation can be drawn using the method described. Negate this assumption and we are left with decreasing amounts of salt and hence no correlation can be accurately undertaken.
Manager
Joined: 11 Apr 2008
Posts: 156
Schools: Kellogg(A), Wharton(W), Columbia(D)
Followers: 1

Kudos [?]: 64 [0], given: 0

### Show Tags

19 Jun 2008, 12:59
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.

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

Negate it ->

The quantities of dissolved salts deposited by rivers in the Earth’s oceans have been unusually large during the past hundred years.

Clearly then our experiment to determine age of the oceans will fail.
So, this is an assumption the argument relies upon.

IMO - A
CEO
Joined: 17 May 2007
Posts: 2989
Followers: 60

Kudos [?]: 579 [0], given: 210

### Show Tags

19 Jun 2008, 14:31
This has been discussed before. A is my answer. It directly supports the premise. E, could be the answer if A weren't there.
Senior Manager
Joined: 07 Jan 2008
Posts: 412
Followers: 3

Kudos [?]: 215 [0], given: 0

### Show Tags

22 Jun 2008, 21:23
We are talking about "quantities of dissolved salts deposited by rivers in the Earth’s oceans" not "salt level of rivers" so B is not correct.

A is OA.
Director
Joined: 23 Sep 2007
Posts: 789
Followers: 5

Kudos [?]: 185 [2] , given: 0

### Show Tags

23 Jun 2008, 00:25
2
KUDOS
Who wrote this question? The vatican? The ocean is at least 2-3 billions years old, and the question is framing the ocean's salinity age in terms of centuries.
Manager
Joined: 09 May 2008
Posts: 102
Followers: 1

Kudos [?]: 19 [0], given: 0

### Show Tags

23 Jun 2008, 03:07
lexis wrote:
We are talking about "quantities of dissolved salts deposited by rivers in the Earth’s oceans" not "salt level of rivers" so B is not correct.

A is OA.

But why is E incorrect ?
Senior Manager
Joined: 16 Aug 2004
Posts: 327
Location: India
Followers: 1

Kudos [?]: 47 [0], given: 0

### Show Tags

23 Jun 2008, 04:33
Hey good one, thank BSD and Anirudh for pointing it out. I guess we normally miss the first option! I fell for E initially.

The method of measurement will hold true only if A is satisfied, ie the incremental measurement is possible only if "The quantities of dissolved salts deposited by rivers in the Earth’s oceans have not been unusually large during the past hundred years" . E is the next best option.
Forum Moderator
Status: mission completed!
Joined: 02 Jul 2009
Posts: 1426
GPA: 3.77
Followers: 180

Kudos [?]: 851 [0], given: 621

### Show Tags

13 Aug 2010, 07:39
Guys,
pls help me why B is wrong?
_________________

Audaces fortuna juvat!

GMAT Club Premium Membership - big benefits and savings

Intern
Joined: 10 Apr 2008
Posts: 25
Followers: 0

Kudos [?]: 5 [0], given: 4

### Show Tags

13 Aug 2010, 09:37
I think E is incorrect because the question talks about the increase in Salt level. Thus, the increase in salt level would account for the amount of salt biologically processed.
SVP
Joined: 17 Feb 2010
Posts: 1558
Followers: 19

Kudos [?]: 572 [1] , given: 6

### Show Tags

13 Aug 2010, 10:51
1
KUDOS
E is incorrect because the argument is talking about the RESULTING INCREASE, which includes the salts that are used up by biological activity in the oceans or for any other purposes.

B is incorrect because the argument is focusing on the ocean's slat level and not the river's salt level.

Only A remains.
Forum Moderator
Status: mission completed!
Joined: 02 Jul 2009
Posts: 1426
GPA: 3.77
Followers: 180

Kudos [?]: 851 [0], given: 621

### Show Tags

13 Aug 2010, 11:27
seekmba wrote:
E is incorrect because the argument is talking about the RESULTING INCREASE, which includes the salts that are used up by biological activity in the oceans or for any other purposes.

B is incorrect because the argument is focusing on the ocean's slat level and not the river's salt level.

Only A remains.

I wrongly understood B as river's level of salt was constant (the same) during the all period of time.
_________________

Audaces fortuna juvat!

GMAT Club Premium Membership - big benefits and savings

Senior Manager
Joined: 18 Jun 2010
Posts: 302
Schools: Chicago Booth Class of 2013
Followers: 26

Kudos [?]: 220 [0], given: 194

### Show Tags

13 Aug 2010, 23:52
I was bought by "B"

Last edited by Financier on 15 Sep 2010, 05:55, edited 1 time in total.
Manager
Joined: 29 Dec 2009
Posts: 122
Location: india
Followers: 2

Kudos [?]: 20 [0], given: 10

### Show Tags

18 Aug 2010, 01:43
A FOR ME
Intern
Joined: 16 Apr 2010
Posts: 34
Followers: 0

Kudos [?]: 9 [0], given: 1

### Show Tags

02 Sep 2010, 08:07
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.
Director
Status: Apply - Last Chance
Affiliations: IIT, Purdue, PhD, TauBetaPi
Joined: 17 Jul 2010
Posts: 690
Schools: Wharton, Sloan, Chicago, Haas
WE 1: 8 years in Oil&Gas
Followers: 15

Kudos [?]: 147 [0], given: 15

### Show Tags

02 Sep 2010, 09:57
So then again what is OA? can someone please clarify...

Posted from my mobile device
_________________

Consider kudos, they are good for health

Intern
Joined: 17 Mar 2010
Posts: 46
Followers: 0

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

### Show Tags

02 Sep 2010, 11:03
Can someone explain why B and E are wrong?
Manager
Joined: 27 Jun 2008
Posts: 85
Location: United States (AL)
Concentration: General Management, Technology
GMAT 1: 660 Q48 V34
WE: Consulting (Computer Software)
Followers: 1

Kudos [?]: 15 [0], given: 22

### Show Tags

02 Sep 2010, 23:12
i chose E,, narrowed it down to a & e,
Manager
Joined: 08 Feb 2010
Posts: 143
Followers: 1

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

### Show Tags

03 Sep 2010, 00:52
Between A and E e seems better.
Re: CR: Ocean salinity   [#permalink] 03 Sep 2010, 00:52

Go to page    1   2    Next  [ 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