Data Sufficiency Question : Quant Question Archive [LOCKED]
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 21 Jan 2017, 13:34

### 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

# Data Sufficiency Question

Author Message
Intern
Joined: 23 Jun 2003
Posts: 2
Followers: 0

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

### Show Tags

12 Jul 2003, 15:02
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Can someone please explain the answer to this question (in the official paper test)

SQRT = Square root

If n and k are positive integers, is SQRT(n+k) > 2 SQRT(n)
(1) k > 3n
(2) n + k > 3n

Eternal Intern
Joined: 07 Jun 2003
Posts: 467
Location: Lone Star State
Followers: 1

Kudos [?]: 144 [0], given: 0

Is it the New paper test for June? [#permalink]

### Show Tags

12 Jul 2003, 15:03

SVP
Joined: 03 Feb 2003
Posts: 1603
Followers: 8

Kudos [?]: 245 [0], given: 0

### Show Tags

13 Jul 2003, 05:13
My rationale:

(1) k>3n; since both k and n are positive integers, the smallest k, satisfying (1) is 3n+1. Check it. sqrt(4n+1)>2sqrt(n) -- correct

Any other k (3n+2, 3n+3, and so on) will be larger, making the original stuff correct as well.

(2) n+k>3n
k>2n

Pick k=3n, then sqrt(4n)=2sqrt(n)
Pick k=10n, then sqrt(11n)>2 sqrt (n)

Different answers; thus, it is wrong

GMAT Instructor
Joined: 07 Jul 2003
Posts: 770
Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE
Followers: 25

Kudos [?]: 205 [0], given: 0

### Show Tags

14 Jul 2003, 00:20
An alternative method might be to restate the question by squaring both sides of the inequality. (raising 2 positive numbers to positive powers maintains the inequality).

"Is sqrt(n + k) > 2 sqrt(n)?" is equivalent to asking "Is n + k > 4 n? " or "is k > 3n?"

1) answers the question directly so A or D.
2) restated say k > 2n. if k > 2n we still don't know k's relationship to 3n so not sufficient, and not D, but A.
_________________

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

Manager
Joined: 03 Jun 2003
Posts: 84
Location: Uruguay
Followers: 1

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

### Show Tags

14 Jul 2003, 07:27
2SQRT (n) = SQRT (4n)

WIth 1) K>3n, so SQRT (n+K) > than SQRT (4n)

With this you can definetely answer the question

With 2) n+K > 3n, here it can be > or < than 4n
SVP
Joined: 03 Feb 2003
Posts: 1603
Followers: 8

Kudos [?]: 245 [0], given: 0

### Show Tags

14 Jul 2003, 21:19
MBA04 wrote:
2SQRT (n) = SQRT (4n)

WIth 1) K>3n, so SQRT (n+K) > than SQRT (4n)

With this you can definetely answer the question

With 2) n+K > 3n, here it can be > or < than 4n

the best approach!
14 Jul 2003, 21:19
Display posts from previous: Sort by