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

It is currently 22 Oct 2018, 18:04

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

What is the largest integer n such that 1/2^n > 0.001?

  post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
Joined: 01 Jun 2009
Posts: 27
What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post Updated on: 25 Jun 2014, 09:13
3
11
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

70% (00:45) correct 30% (00:48) wrong based on 372 sessions

HideShow timer Statistics

What is the largest integer n such that \(\frac{1}{2^n}> 0.01\) ?

(A) 5
(B) 6
(C) 7
(D) 10
(E) 51

Here is what I did:

[1/(2^n)] > 1/100
Hence, (2^n) > 100
but the book says it'll be (2^n) < 100

Can someone tell me why did the sign change?

Thanks!


OPEN DISCUSSION OF THIS QUESTION IS HERE: what-is-the-largest-integer-n-such-that-1-2-n-167373.html

Originally posted by bfman on 04 Jul 2010, 18:52.
Last edited by Bunuel on 25 Jun 2014, 09:13, edited 1 time in total.
Renamed the topic and edited the question.
CEO
CEO
User avatar
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2605
Location: Malaysia
Concentration: Technology, Entrepreneurship
Schools: ISB '15 (M)
GMAT 1: 670 Q49 V31
GMAT 2: 710 Q50 V35
Reviews Badge
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 04 Jul 2010, 19:19
bfman wrote:
Page 73. Q: 86

What is the largest integer n such that [1/(2^n)] > 0.01 ?

A. 5
B. 6
C. 7
D. 10
E. 51

Here is what I did:

[1/(2^n)] > 1/100
Hence, (2^n) > 100
but the book says it'll be (2^n) < 100

Can someone tell me why did the sign change?

Thanks!


1/2 > 1/3
=> 3>2, but according to you, 2>3

1/x > 1/y

if both x and y are +ve

cross multiple
which gives y>x

if there is -ve sign then also inequality sign is reversed.

PS: If you have problem with quants, do buy number prop and inequality books by Mgmat
_________________

Fight for your dreams :For all those who fear from Verbal- lets give it a fight

Money Saved is the Money Earned :)

Jo Bole So Nihaal , Sat Shri Akaal

:thanks Support GMAT Club by putting a GMAT Club badge on your blog/Facebook :thanks

GMAT Club Premium Membership - big benefits and savings

Gmat test review :
http://gmatclub.com/forum/670-to-710-a-long-journey-without-destination-still-happy-141642.html

Intern
Intern
avatar
Joined: 01 Jun 2009
Posts: 27
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 04 Jul 2010, 19:56
ohhh cross multipyyyyy.... I was taking the denominators as is... I thought it was ok to do that.
VP
VP
avatar
Joined: 17 Feb 2010
Posts: 1156
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 10 Aug 2010, 18:36
1
In inequalities,

if both x and y are positive and \((1/x) > (1/y)\) then, \(x < y\)

In the question given

\((1/2^n) > 0.01\)

\((1/2^n) > 1/100\)

\(2^n < 100\)

\(2^6 = 64\)

\(2^7 = 128\) which is greater than 100.

\(Thus, 2^6 < 100\)

Hence \(n=6\)
Senior Manager
Senior Manager
User avatar
Status: Time to step up the tempo
Joined: 24 Jun 2010
Posts: 365
Location: Milky way
Schools: ISB, Tepper - CMU, Chicago Booth, LSB
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 10 Aug 2010, 18:57
Quote:
Page 73. Q: 86

What is the largest integer n such that [1/(2^n)] > 0.01 ?

A. 5
B. 6
C. 7
D. 10
E. 51


Guess it is easy for people who deal with bits and bytes to crack this within 30 secs...

\(1/(2^n) > 1/100
==>
1/(2^6) > 1/100\) and \(1/(2^7) < 1/100\). Hence largest integer n would be 6.
_________________

:good Support GMAT Club by putting a GMAT Club badge on your blog :thanks

Senior Manager
Senior Manager
User avatar
Status: Fighting on
Joined: 14 Mar 2010
Posts: 293
Schools: UCLA (R1 interview-WL), UNC(R2--interview-ding) Oxford(R2-Admit), Kelley (R2- Admit $$), McCombs(R2)
WE 1: SE - 1
WE 2: Engineer - 3
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 10 Aug 2010, 19:22
1/(2^n) > 1/100
=> 100 > 2^n

the only max n possible is 6 from the choices
Intern
Intern
avatar
Joined: 11 Mar 2011
Posts: 2
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 30 Sep 2011, 14:05
86) What is the largest integer N such that 1/2^n greater than 0.01?

a. 5
b.6
c. 7
d. 10
e. 51

I understand a little bit of the explanation from the guide book,
but why/ how did they remove the fraction?
and why is 6 the answer, why couldn't it be 2 to the 7th , 10th or 51st. all of those answers should be greater than 100.
Senior Manager
Senior Manager
User avatar
Joined: 08 Nov 2010
Posts: 342
WE 1: Business Development
GMAT ToolKit User
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 30 Sep 2011, 14:27
1
Slash2009 wrote:
86) What is the largest integer N such that 1/2^n greater than 0.01?

a. 5
b.6
c. 7
d. 10
e. 51

I understand a little bit of the explanation from the guide book,
but why/ how did they remove the fraction?
and why is 6 the answer, why couldn't it be 2 to the 7th , 10th or 51st. all of those answers should be greater than 100.


Bc we know that \(2^n\) and 100 are +ve, we can cross multiply.
and we will receive -
\(2^n<100\)

we know that \(2^6 = 64\), if we multiply 64 in 2 again - we will have a number greater than 100. so it must be that n=6 (max)

You can find the a full existing discussion here:
http://gmatclub.com/forum/from-quant-og-powers-question-96753.html
_________________

GMAT Club Premium Membership - big benefits and savings

Intern
Intern
avatar
Joined: 11 Mar 2011
Posts: 2
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 30 Sep 2011, 14:49
Thanks Yo, I need to pay attention to the greater than , less than signs
Director
Director
avatar
Joined: 01 Feb 2011
Posts: 668
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 30 Sep 2011, 17:57
1/(2^n) > 1/(10^2)

multiplying by 2^n on both sides we have (as 2^n is always positive ,we don't have change sign)

1 > 2^n / 10^2

multiplying by 10^2 on both sides we have

100 > 2^n

In other words 2^n < 100

plugging in values we can see that max value of n that satisfy the above condition is 6.

Answer is B.
Manager
Manager
avatar
Joined: 20 Nov 2010
Posts: 161
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 02 Oct 2011, 11:05
1/2^n > 1/100
=> 2^n < 100
n < 7 => n = 6.
B is the answer.
_________________

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
MGMAT 6 650 (51,31) on 31/8/11
MGMAT 1 670 (48,33) on 04/9/11
MGMAT 2 670 (47,34) on 07/9/11
MGMAT 3 680 (47,35) on 18/9/11
GMAT Prep1 680 ( 50, 31) on 10/11/11

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
CR notes
http://gmatclub.com/forum/massive-collection-of-verbal-questions-sc-rc-and-cr-106195.html#p832142
http://gmatclub.com/forum/1001-ds-questions-file-106193.html#p832133
http://gmatclub.com/forum/gmat-prep-critical-reasoning-collection-106783.html
http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html
http://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html?hilit=chineseburned

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 50042
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 25 Jun 2014, 09:13
1
bfman wrote:
What is the largest integer n such that \(\frac{1}{2^n}> 0.01\) ?

(A) 5
(B) 6
(C) 7
(D) 10
(E) 51


\(\frac{1}{2^n}> 0.01\);

\(\frac{1}{2^n}> \frac{1}{100}\);

\(2^n<100\);

\(2^6=64<100\) and \(2^7=128>100\), therefore, 6 is the largest integer such that \(\frac{1}{2^n}> 0.01\).

Answer: B.

OPEN DISCUSSION OF THIS QUESTION IS HERE: what-is-the-largest-integer-n-such-that-1-2-n-167373.html
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 8531
Premium Member
Re: What is the largest integer n such that 1/2^n > 0.001?  [#permalink]

Show Tags

New post 26 Sep 2018, 22:55
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

GMAT Club Bot
Re: What is the largest integer n such that 1/2^n > 0.001? &nbs [#permalink] 26 Sep 2018, 22:55
Display posts from previous: Sort by

What is the largest integer n such that 1/2^n > 0.001?

  post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

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

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®.