GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 20 Oct 2019, 04:21

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.

Close

Request Expert Reply

Confirm Cancel

If 0.0030<x-√30<0.0031, which of the following options is the approxim

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Senior SC Moderator
User avatar
V
Joined: 14 Nov 2016
Posts: 1348
Location: Malaysia
GMAT ToolKit User
If 0.0030<x-√30<0.0031, which of the following options is the approxim  [#permalink]

Show Tags

New post 23 Feb 2017, 19:38
1
2
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

61% (02:10) correct 39% (02:11) wrong based on 74 sessions

HideShow timer Statistics

If \(0.0030<x-\sqrt{30}<0.0031\), which of the following options is the approximation of  \(\frac{1}{\sqrt{30}}-\frac{1}{x}\)?

A. 0.001     
B. 0.002     
C. 0.0001     
D. 0.0002     
E. 0.0003

_________________
"Be challenged at EVERY MOMENT."

“Strength doesn’t come from what you can do. It comes from overcoming the things you once thought you couldn’t.”

"Each stage of the journey is crucial to attaining new heights of knowledge."

Rules for posting in verbal forum | Please DO NOT post short answer in your post!

Advanced Search : https://gmatclub.com/forum/advanced-search/
Senior Manager
Senior Manager
avatar
B
Joined: 13 Oct 2016
Posts: 359
GPA: 3.98
Re: If 0.0030<x-√30<0.0031, which of the following options is the approxim  [#permalink]

Show Tags

New post 24 Feb 2017, 01:46
3
AustinKL wrote:
If \(0.0030<x-\sqrt{30}<0.0031\), which of the following options is the approximation of  \(\frac{1}{\sqrt{30}}-\frac{1}{x}\)?

A. 0.001     
B. 0.002     
C. 0.0001     
D. 0.0002     
E. 0.0003


Hi

\(0.0030<x-\sqrt{30}<0.0031\)

\(\sqrt{30} + 0.0030 < x < \sqrt{30} + 0.0031\)

\(\frac{1}{\sqrt{30}}-\frac{1}{x}\) = \((x - \sqrt{30}) / x * \sqrt{30}\)

\(min = \frac{0.003}{(\sqrt{30} + 0.003)*\sqrt{30}} = \frac{0.003}{30 + 0.003*\sqrt{30}} ≈ \frac{0.003}{30} = \frac{3*0.001}{3*10} = 0.0001\)

\(max = \frac{0.0031}{(\sqrt{30} + 0.0031)*\sqrt{30}} = \frac{0.0031}{30 + 0.0031*\sqrt{30}} ≈ \frac{0.0031}{30} = \frac{0.003}{30} + \frac{0.0001}{30} ≈ \frac{0.003}{30} = 0.0001\)
.

Answer C.
VP
VP
User avatar
D
Joined: 09 Mar 2016
Posts: 1230
If 0.0030<x-√30<0.0031, which of the following options is the approxim  [#permalink]

Show Tags

New post 30 Sep 2018, 12:09
2
hazelnut wrote:
If \(0.0030<x-\sqrt{30}<0.0031\), which of the following options is the approximation of  \(\frac{1}{\sqrt{30}}-\frac{1}{x}\)?

A. 0.001     
B. 0.002     
C. 0.0001     
D. 0.0002     
E. 0.0003


here is my approach

The \(\sqrt{30}\) is about 5.4

Hence x is between \(0.0030<x-5.4<0.0031\) add 5.4 to both sides so difference between maximum and minimum value is 0.0001

so I clicked on C :) :lol:
Senior Manager
Senior Manager
avatar
P
Joined: 27 Dec 2016
Posts: 309
CAT Tests
Re: If 0.0030<x-√30<0.0031, which of the following options is the approxim  [#permalink]

Show Tags

New post 14 Mar 2019, 19:02
Hi chetan2u Bunuel VeritasKarishma,

I was wondering could one of you experts please share an easier approach to solving this problem? Would greatly appreciate it!
GMAT Club Bot
Re: If 0.0030<x-√30<0.0031, which of the following options is the approxim   [#permalink] 14 Mar 2019, 19:02
Display posts from previous: Sort by

If 0.0030<x-√30<0.0031, which of the following options is the approxim

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne