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

It is currently 25 Oct 2014, 08:18

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

root{463} is between

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 10 Aug 2012
Posts: 5
Followers: 0

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

root{463} is between [#permalink] New post 12 Aug 2012, 08:31
1
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

91% (01:22) correct 9% (00:56) wrong based on 104 sessions
\sqrt{463} is between

(A) 21 and 22
(B) 22 and 23
(C) 23 and 24
(D) 24 and 25
(E) 25 and 26

What is the fastest way to solve this problem?
[Reveal] Spoiler: OA
Intern
Intern
avatar
Joined: 10 Aug 2012
Posts: 5
Followers: 0

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

Re: [square_root]463[/square_root] is between [#permalink] New post 12 Aug 2012, 08:35
The way I solved it was by realizing

20^2= 400

so 21^2 = 20^2 +20 + 1*21 = 441

and

22^2 = 20^2 +20*2 + 2*21 = 440 + 40 + 42 > 500

so \sqrt{463} is >21 but <22

still wasn't that fast, but it made me think there might be some formula or something.
Director
Director
User avatar
Joined: 22 Mar 2011
Posts: 612
WE: Science (Education)
Followers: 73

Kudos [?]: 529 [0], given: 43

Re: [square_root]463[/square_root] is between [#permalink] New post 12 Aug 2012, 08:58
JustinDragna wrote:
The way I solved it was by realizing

20^2= 400

so 21^2 = 20^2 +20 + 1*21 = 441

and

22^2 = 20^2 +20*2 + 2*21 = 440 + 40 + 42 > 500

so \sqrt{463} is >21 but <22

still wasn't that fast, but it made me think there might be some formula or something.


Your reasoning is perfect. And there is no magic formula to help here.
_________________

PhD in Applied Mathematics
Love GMAT Quant questions and running.

Manager
Manager
avatar
Joined: 05 Jul 2012
Posts: 82
Location: India
Concentration: Finance, Strategy
GMAT Date: 09-30-2012
GPA: 3.08
WE: Engineering (Energy and Utilities)
Followers: 4

Kudos [?]: 18 [0], given: 8

Re: [square_root]463[/square_root] is between [#permalink] New post 12 Aug 2012, 18:27
JustinDragna wrote:
The way I solved it was by realizing

20^2= 400

so 21^2 = 20^2 +20 + 1*21 = 441

and

22^2 = 20^2 +20*2 + 2*21 = 440 + 40 + 42 > 500

so \sqrt{463} is >21 but <22

still wasn't that fast, but it made me think there might be some formula or something.



The other way is to find the square root of 463 first and then compare it, but even this method will require atleast 3-4 iterations and is pretty long.
CEO
CEO
User avatar
Joined: 09 Sep 2013
Posts: 2863
Followers: 207

Kudos [?]: 43 [0], given: 0

Premium Member
Re: root{463} is between [#permalink] New post 06 Sep 2014, 15:59
Hello from the GMAT Club BumpBot!

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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

VP
VP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1088
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Followers: 6

Kudos [?]: 311 [0], given: 170

Re: root{463} is between [#permalink] New post 08 Sep 2014, 22:52
21^2 = 441

22^2 = 484

Answer = A
_________________

Kindly press "+1 Kudos" to appreciate :)

Re: root{463} is between   [#permalink] 08 Sep 2014, 22:52
    Similar topics Author Replies Last post
Similar
Topics:
3 Experts publish their posts in the topic Is s between r and t pnf619 5 02 Sep 2012, 07:03
difference between to be and as vaivish1723 6 19 Jun 2009, 12:38
1 Economist: In the interaction between producers and gmataquaguy 15 12 May 2005, 12:53
In a study of the relationship between aggression and chunjuwu 9 16 Mar 2005, 03:58
Difference between a MBA and an EMBA ywilfred 1 06 Dec 2004, 00:12
Display posts from previous: Sort by

root{463} is between

  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®.