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

It is currently 26 Nov 2014, 05:59

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

If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
1 KUDOS received
Manager
Manager
avatar
Joined: 14 Mar 2010
Posts: 87
Followers: 2

Kudos [?]: 26 [1] , given: 44

If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))? [#permalink] New post 20 May 2012, 00:38
1
This post received
KUDOS
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

66% (02:37) correct 34% (01:32) wrong based on 66 sessions
If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))?

A. 6
B. 3
C. 0
D. –3
E. –6
[Reveal] Spoiler: OA

_________________

MGMAT CAT MATH mgmat-cat-math-144609.html
MGMAT SC SUMMARY: mgmat-sc-summary-144610.html


Last edited by Bunuel on 20 May 2012, 11:32, edited 1 time in total.
Edited the question and added the OA
2 KUDOS received
Manager
Manager
User avatar
Affiliations: Project Management Professional (PMP)
Joined: 30 Jun 2011
Posts: 213
Location: New Delhi, India
Followers: 3

Kudos [?]: 31 [2] , given: 12

Re: If P(r)=8r/(1-r) [#permalink] New post 20 May 2012, 03:21
2
This post received
KUDOS
monir6000 wrote:
If P(r)=8r/(1-r), for what value of r does P(r)=1/2*(P(3))?

A. 6
B. 3
C. 0
D. –3
E. –6


P(r) = 8r / (1-r)

P(3) = 8*3 / ( 1-3 ) = - 12

1/2 * P(3) = - 6

P(r) = - 6

=> 8r / ( 1-r ) = - 6

=> 8r = 6r - 6

=> 2r = - 6

=> r = - 3
_________________

Best
Vaibhav

If you found my contribution helpful, please click the +1 Kudos button on the left, Thanks

Manager
Manager
avatar
Joined: 14 Mar 2010
Posts: 87
Followers: 2

Kudos [?]: 26 [0], given: 44

Re: If P(r)=8r/(1-r) [#permalink] New post 20 May 2012, 03:28
thanks a lot.....very helpful +1 kudos...
_________________

MGMAT CAT MATH mgmat-cat-math-144609.html
MGMAT SC SUMMARY: mgmat-sc-summary-144610.html

Intern
Intern
avatar
Joined: 12 Dec 2013
Posts: 20
Followers: 1

Kudos [?]: 2 [0], given: 29

Re: If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))? [#permalink] New post 17 Oct 2014, 02:18
If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))?

A. 6
B. 3
C. 0
D. –3
E. –6

Can someone explain this problem again? I got it till -12, but wasn't sure what to do after this? Thanks in advance!
Expert Post
Math Expert
User avatar
Joined: 02 Sep 2009
Posts: 24092
Followers: 3737

Kudos [?]: 31300 [0], given: 3310

Re: If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))? [#permalink] New post 17 Oct 2014, 06:00
Expert's post
Rca wrote:
If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))?

A. 6
B. 3
C. 0
D. –3
E. –6

Can someone explain this problem again? I got it till -12, but wasn't sure what to do after this? Thanks in advance!


P(r) = \frac{8r}{1-r}, so P(3) = \frac{8*3}{1-3} = - 12.

We need to find for what value of r does P(r)=\frac{1}{2}*P(3), so for what value of r does P(r)=\frac{1}{2}*(-12). So, we soulh solve for r the following: \frac{8r}{1-r}=\frac{1}{2}*(-12) --> r=-3.

Answer: D.

Check questions about functions in Special Questions Directory:

Operations/functions defining algebraic/arithmetic expressions
Symbols Representing Arithmetic Operation
Rounding Functions
Various Functions

Hope this helps.
_________________

NEW TO MATH FORUM? PLEASE READ THIS: ALL YOU NEED FOR QUANT!!!

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders; 11. GMAT Prep Software Analysis NEW!!!; 12. SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) NEW!!!; 12. Tricky questions from previous years. NEW!!!;

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?
25 extra-hard Quant Tests

Take a Survey about GMAT Prep - Win Prizes!

Intern
Intern
avatar
Joined: 12 Dec 2013
Posts: 20
Followers: 1

Kudos [?]: 2 [0], given: 29

Re: If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))? [#permalink] New post 18 Oct 2014, 03:18
Got it! Thank you so much Bunuel. I keep missing out on small stuff.
Re: If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))?   [#permalink] 18 Oct 2014, 03:18
    Similar topics Author Replies Last post
Similar
Topics:
What is the value of R? 1. R^R = R 2. suntaurian 4 05 Mar 2008, 16:46
What is the value of R? 1. R^R = R 2. (1/R)^R = R Can bmwhype2 9 08 Nov 2007, 03:34
If + |R| = 0, what are the possible values of R bmwhype2 6 30 Sep 2007, 15:06
If r ^3 + | r | = 0, what are the possible values of r ? ggarr 3 28 Dec 2006, 16:40
If r ^3 + | r | = 0, what are the possible values of r ? I ggarr 4 01 Nov 2006, 17:01
Display posts from previous: Sort by

If P(r)=8r/(1-r), for what value of r does P(r)=1/2(P(3))?

  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®.