Author 
Message 
TAGS:

Hide Tags

Senior Manager
Joined: 10 Mar 2008
Posts: 360

In the formula V = 1/(2r)^3, if r is halved, then V is multi [#permalink]
Show Tags
15 Jul 2008, 12:39
6
This post was BOOKMARKED
Question Stats:
69% (01:44) correct
31% (00:56) wrong based on 253 sessions
HideShow timer Statistics
In the formula V = 1/(2r)^3, if r is halved, then V is multiplied by A. 64 B. 8 C. 1 D. 1/8 E. 1/64
Official Answer and Stats are available only to registered users. Register/ Login.
Last edited by Bunuel on 21 Feb 2014, 05:10, edited 1 time in total.
Renamed the topic, edited the question and added the OA.



SVP
Joined: 30 Apr 2008
Posts: 1874
Location: Oklahoma City
Schools: Hard Knocks

Re: PS: formula V= 1/(2r)^3 [#permalink]
Show Tags
15 Jul 2008, 12:42
B  about had that backwards Make r = 1/2, V = 1 Make r = 1, v = 1/8
_________________
 J Allen Morris **I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.
GMAT Club Premium Membership  big benefits and savings



Senior Manager
Joined: 07 Jan 2008
Posts: 289

Re: PS: formula V= 1/(2r)^3 [#permalink]
Show Tags
15 Jul 2008, 13:00
I always mess up these kinds... Say r=2 => V1 = 1/64 when r=1; V2 = 1/8 V2 = 8*V1. B?



SVP
Joined: 30 Apr 2008
Posts: 1874
Location: Oklahoma City
Schools: Hard Knocks

Re: PS: formula V= 1/(2r)^3 [#permalink]
Show Tags
15 Jul 2008, 13:05
I totally agree with you. I mess them up to and about did this one. I saw that if I make 2r = 1, then r=1/2 so to the power of 3 doesn't matter, it's still 1/1. Then I did r =1 (double it) so then V = 1/8. So I was thinking oh, go from 1 to 1/8 multiply by 1/8...but I had worked the problem backwards. There are tricks the authors throw at us, and then there are tricks we bring to the test ourselves. We have to eliminate our own tricks. Easier said than done! mbawaters wrote: I always mess up these kinds... Say r=2 => V1 = 1/64 when r=1; V2 = 1/8 V2 = 8*V1. B?
_________________
 J Allen Morris **I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.
GMAT Club Premium Membership  big benefits and savings



Senior Manager
Joined: 10 Mar 2008
Posts: 360

Re: PS: formula V= 1/(2r)^3 [#permalink]
Show Tags
15 Jul 2008, 13:09
So isnt the qtn essentially testing us on: if r is halved then what should V be multiplied by to retain the intial formula???



Senior Manager
Joined: 07 Jan 2008
Posts: 289

Re: PS: formula V= 1/(2r)^3 [#permalink]
Show Tags
15 Jul 2008, 15:30
vksunder wrote: So isnt the qtn essentially testing us on: if r is halved then what should V be multiplied by to retain the intial formula??? I think its asking us to reflect the changes in the value of V if r is halved!



Senior Manager
Joined: 09 Oct 2007
Posts: 466

Re: PS: formula V= 1/(2r)^3 [#permalink]
Show Tags
15 Jul 2008, 23:22
vksunder wrote: So isnt the qtn essentially testing us on: if r is halved then what should V be multiplied by to retain the intial formula??? Not really, it's asking what happens to V when r is halved. In this type of problems, just pick an easy value for r and solve both equations.



Intern
Joined: 29 Jan 2014
Posts: 27
GMAT 1: 510 Q36 V26 GMAT 2: 550 Q38 V28

Re: In the formula V= 1/(2r)^3, if r is halved, then V is [#permalink]
Show Tags
21 Feb 2014, 03:14
Can someone solve this question with an explanation? Thanks
_________________
Please give me Kudos if you like my post. Thank you



Math Expert
Joined: 02 Sep 2009
Posts: 39718

Re: In the formula V= 1/(2r)^3, if r is halved, then V is [#permalink]
Show Tags
21 Feb 2014, 05:28
1
This post received KUDOS
Expert's post
2
This post was BOOKMARKED



Intern
Joined: 29 Jan 2014
Posts: 27
GMAT 1: 510 Q36 V26 GMAT 2: 550 Q38 V28

Re: In the formula V = 1/(2r)^3, if r is halved, then V is multi [#permalink]
Show Tags
21 Feb 2014, 07:34
Thanks a lot Bunuel!
_________________
Please give me Kudos if you like my post. Thank you



GMAT Club Legend
Joined: 09 Sep 2013
Posts: 16001

Re: In the formula V = 1/(2r)^3, if r is halved, then V is multi [#permalink]
Show Tags
07 Apr 2015, 20:28
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 Legend
Joined: 09 Sep 2013
Posts: 16001

Re: In the formula V = 1/(2r)^3, if r is halved, then V is multi [#permalink]
Show Tags
19 Sep 2016, 04:26
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




Re: In the formula V = 1/(2r)^3, if r is halved, then V is multi
[#permalink]
19 Sep 2016, 04:26








Similar topics 
Author 
Replies 
Last post 
Similar Topics:




To halve the value of the expression above by doubling exactly one of

Bunuel 
7 
05 Jun 2017, 15:49 

2


If V = 12R / (r + R) , then R = A. Vr / (12  V) B. Vr + V /12 C. V

SajjadAhmad 
4 
19 Feb 2017, 11:56 

1


In the formula w = \frac{p}{\sqrt[t]{v}} , integers p and t are positi

Bunuel 
2 
29 Nov 2015, 20:49 

6


For all real numbers V, the operation V* is defined by the equation V*

Bunuel 
7 
28 Aug 2015, 05:03 



In the formula, V = 1/(2r)^2, if r is tripled, then V is

enigma123 
2 
19 Feb 2012, 22:02 



