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

It is currently 26 Sep 2018, 07:58

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

The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of

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

Hide Tags

Senior CR Moderator
User avatar
V
Status: Long way to go!
Joined: 10 Oct 2016
Posts: 1384
Location: Viet Nam
GMAT ToolKit User Premium Member
The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of  [#permalink]

Show Tags

New post 11 Apr 2017, 07:06
3
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

70% (02:10) correct 30% (02:10) wrong based on 125 sessions

HideShow timer Statistics

The value of \(3^{-2} + 3^{-4} + 3^{-6}\) is how many times the value of \(3^{-5}\)?

A. \(\frac{91}{3}\)

B. 27

C. \(\frac{31}{3}\)

D. 3

E. \(\frac{1}{3}\)

Source: GMAT Free

_________________

Actual LSAT CR bank by Broall

How to solve quadratic equations - Factor quadratic equations
Factor table with sign: The useful tool to solve polynomial inequalities
Applying AM-GM inequality into finding extreme/absolute value

New Error Log with Timer

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49544
Re: The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of  [#permalink]

Show Tags

New post 11 Apr 2017, 07:08
nguyendinhtuong wrote:
The value of \(3^{-2} + 3^{-4} + 3^{-6}\) is how many times the value of \(3^{-5}\)?

A. \(\frac{91}{3}\)

B. 27

C. \(\frac{31}{3}\)

D. 3

E. \(\frac{1}{3}\)

Source: GMAT Free


Similar question: https://gmatclub.com/forum/the-value-of ... 30682.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

BSchool Forum Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 3141
Location: India
GPA: 3.12
Premium Member CAT Tests
Re: The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of  [#permalink]

Show Tags

New post 11 Apr 2017, 07:50
3^-2 = 1/3^2
Hence using this logic, rewriting the above equation, we get
1/3^2 + 1/3^4 + 1/3^6
= (3^4 + 3^2 + 1)/3^6
= 91/3^6
This is 91/3 times 1/3^5(Option A)

Sent from my LG-H818 using GMAT Club Forum mobile app
_________________

You've got what it takes, but it will take everything you've got

Manager
Manager
User avatar
Joined: 20 Dec 2013
Posts: 123
Re: The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of  [#permalink]

Show Tags

New post 11 Apr 2017, 08:29
1
nguyendinhtuong wrote:
The value of \(3^{-2} + 3^{-4} + 3^{-6}\) is how many times the value of \(3^{-5}\)?

A. \(\frac{91}{3}\)

B. 27

C. \(\frac{31}{3}\)

D. 3

E. \(\frac{1}{3}\)

Source: GMAT Free


You can divide (3^-2 + 3^-4 + 3^-6) by 3^-5

We get: 3^-2+5 + 3^1 + 3^-1 = 27 + 3 + 1/3 = 30 + 1/3 = 91/3 Hence A
_________________

76000 Subscribers, 7 million minutes of learning delivered and 5.6 million video views

Perfect Scores
http://perfectscores.org
http://www.youtube.com/perfectscores

Board of Directors
User avatar
P
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4032
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member
Re: The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of  [#permalink]

Show Tags

New post 11 Apr 2017, 12:19
1
1
nguyendinhtuong wrote:
The value of \(3^{-2} + 3^{-4} + 3^{-6}\) is how many times the value of \(3^{-5}\)?

A. \(\frac{91}{3}\)

B. 27

C. \(\frac{31}{3}\)

D. 3

E. \(\frac{1}{3}\)

Source: GMAT Free


\(3^{-2} + 3^{-4} + 3^{-6}\)

= \(3^{-2} ( 1 + 3^{-2} + 3^{-4}\) )

= \(\frac{1}{9} ( 1 + \frac{1}{9} + \frac{1}{81} )\)

= \(\frac{1}{9} ( \frac{81 + 9 + 1}{81} )\)

= \(\frac{91}{729}\)


Quote:
is how many times the value of \(3^{-5}\)?


So, \(\frac{91}{729}*\frac{243}{1}\) = \(\frac{91}{3}\)

Hence, answer must be (A) \(\frac{91}{3}\)
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

CEO
CEO
User avatar
D
Joined: 12 Sep 2015
Posts: 2908
Location: Canada
Re: The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of  [#permalink]

Show Tags

New post 11 Apr 2017, 12:29
Top Contributor
2
nguyendinhtuong wrote:
The value of \(3^{-2} + 3^{-4} + 3^{-6}\) is how many times the value of \(3^{-5}\)?

A. \(\frac{91}{3}\)

B. 27

C. \(\frac{31}{3}\)

D. 3

E. \(\frac{1}{3}\)

Source: GMAT Free


Let's factor out \(3^{-5}\)

We get: \(3^{-2} + 3^{-4} + 3^{-6} = 3^{-5}(3^3 + 3^1 + 3^{-1})\)

\(= 3^{-5}(27 + 3 + \frac{1}{3})\)

\(= 3^{-5}(30 + \frac{1}{3})\)

\(= 3^{-5}(\frac{90}{3} + \frac{1}{3})\)

\(= 3^{-5}(\frac{91}{3})\)

Answer:

Cheers,
Brent
_________________

Brent Hanneson – GMATPrepNow.com
Image
Sign up for our free Question of the Day emails

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 8196
Premium Member
Re: The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of  [#permalink]

Show Tags

New post 13 Jul 2018, 08:03
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: The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of &nbs [#permalink] 13 Jul 2018, 08:03
Display posts from previous: Sort by

The value of 3^(-2)+3^(-4)+3^(-6) is how many times the value of

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

Events & Promotions

PREV
NEXT


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®.