NEW HERE? LEARN MORE
closeclose
Last visit was: 24 Apr 2024, 10:16 It is currently 24 Apr 2024, 10:16
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

if a=2b^3/c what happens to c when a is halved and b is

User avatar
gmatiscoming
Manager
Manager
Joined: 04 May 2007
Posts: 71
Own Kudos [?]: 25 [0]
Given Kudos: 0
Send PM
if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   26 May 2007, 15:52
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Hide Show timer Statistics
if a=2b^3/c what happens to c when a is halved and b is doubled?

a - c is not changed
b- c is halved
c- c is doubled
d- c is multiplied by 4
e - c is multipled by 16





can someone walk me through this problem step by step (without plugging in)
i botched it somewheres



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
LM
Senior Manager
Senior Manager
Joined: 03 Sep 2006
Posts: 446
Own Kudos [?]: 6776 [0]
Given Kudos: 33
Send PM
GMAT ToolKit User
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   26 May 2007, 18:32
gmatiscoming wrote:
if a=2b^3/c what happens to c when a is halved and b is doubled?

a - c is not changed
b- c is halved
c- c is doubled
d- c is multiplied by 4
e - c is multipled by 16





can someone walk me through this problem step by step (without plugging in)
i botched it somewheres


Initially take any value which meets the given equation, for example;

b = 1,

c = 3

thus a = 2.

Next, halve the a = 1 and double the b = 2, put them in the equation and you will see in order to satisfy the equation, the value of c has to be consistently = 3.

Thus value of c remans unchanged.

These are fairly easy questions which you have posted? When is your GMAT date?
User avatar
Hayabusa
Intern
Intern
Joined: 22 May 2007
Posts: 47
Own Kudos [?]: 15 [0]
Given Kudos: 0
Send PM
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   26 May 2007, 19:09
LM, are you sure about that?? I think the answer is E.
User avatar
LM
Senior Manager
Senior Manager
Joined: 03 Sep 2006
Posts: 446
Own Kudos [?]: 6776 [0]
Given Kudos: 33
Send PM
GMAT ToolKit User
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   26 May 2007, 19:13
Hayabusa wrote:
LM, are you sure about that?? I think the answer is E.


Could you please explain why is it E? I did not follow any mathematical approach for this one, may be I am wrong..I was just putting in the values to get the answer.
User avatar
Hayabusa
Intern
Intern
Joined: 22 May 2007
Posts: 47
Own Kudos [?]: 15 [0]
Given Kudos: 0
Send PM
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   26 May 2007, 19:21
Well I might be wrong, but here is what I did:

a=2b^3/c , solve for c an we get c=2b^3/a. Lets plug for a=4 and b=5
We get c=62.5

Now lets double b and divide a by 2, we get a=2 and b=10. Plug in and we get 1000 which is 62.5 times 16.
User avatar
Himalayan
Senior Manager
Senior Manager
Joined: 26 Feb 2006
Posts: 384
Own Kudos [?]: 583 [0]
Given Kudos: 0
Send PM
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   26 May 2007, 19:50
gmatiscoming wrote:
if a=2b^3/c what happens to c when a is halved and b is doubled?

a - c is not changed
b- c is halved
c- c is doubled
d- c is multiplied by 4
e - c is multipled by 16

can someone walk me through this problem step by step (without plugging in)
i botched it somewheres


I believe a=2b^3/c is a = (2b^3) / c

if so, it should be E.

a = (2b^3) / c
c = (2b^3) / a

if a is halved and b is doubled
a/2 = [2(2b)^3] / c
c = [2x 2 x 8b^3] / a
c = (32b^3) / a

so C should be multiplied by 16.
User avatar
Dek
Manager
Manager
Joined: 14 Mar 2007
Posts: 52
Own Kudos [?]: 33 [0]
Given Kudos: 0
Send PM
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   27 May 2007, 02:35
LM wrote:

Initially take any value which meets the given equation, for example;

b = 1,

c = 3

thus a = 2.

Next, halve the a = 1 and double the b = 2, put them in the equation and you will see in order to satisfy the equation, the value of c has to be consistently = 3.

Thus value of c remans unchanged.

These are fairly easy questions which you have posted? When is your GMAT date?



The ans is E not A!! :roll:
User avatar
kirakira
Manager
Manager
Joined: 02 May 2007
Posts: 54
Own Kudos [?]: 8 [0]
Given Kudos: 0
Send PM
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   27 May 2007, 02:39
gmatiscoming wrote:
if a=2b^3/c what happens to c when a is halved and b is doubled?

a - c is not changed
b- c is halved
c- c is doubled
d- c is multiplied by 4
e - c is multipled by 16





can someone walk me through this problem step by step (without plugging in)

i botched it somewheres



(E) certainly :)
User avatar
gmatiscoming
Manager
Manager
Joined: 04 May 2007
Posts: 71
Own Kudos [?]: 25 [0]
Given Kudos: 0
Send PM
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   27 May 2007, 08:48
LM wrote:
gmatiscoming wrote:
if a=2b^3/c what happens to c when a is halved and b is doubled?

a - c is not changed
b- c is halved
c- c is doubled
d- c is multiplied by 4
e - c is multipled by 16





can someone walk me through this problem step by step (without plugging in)
i botched it somewheres


Initially take any value which meets the given equation, for example;

b = 1,

c = 3

thus a = 2.

Next, halve the a = 1 and double the b = 2, put them in the equation and you will see in order to satisfy the equation, the value of c has to be consistently = 3.

Thus value of c remans unchanged.

These are fairly easy questions which you have posted? When is your GMAT date?


hey LM,

thanks for your smart ass comment, btw. just in case you didn't know you got the answer wrong too... the OA is E. so when is your GMAT date? you f$%! keep your snide remarks to yourself
tool.
User avatar
B
kevincan
GMAT Instructor
Joined: 04 Jul 2006
Posts: 960
Own Kudos [?]: 693 [0]
Given Kudos: 6
Location: Madrid
 Q51  V50
Send PM
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink] New post   27 May 2007, 09:36
gmatiscoming wrote:
if a=2b^3/c what happens to c when a is halved and b is doubled?

a - c is not changed
b- c is halved
c- c is doubled
d- c is multiplied by 4
e - c is multipled by 16





can someone walk me through this problem step by step (without plugging in)
i botched it somewheres

The new value of a is a/2 and the new value of b is 2b.

Thus the new value of c is (2b)^3/(a/2)=16b^3/a=16c.



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
GMAT Club Bot
gmatclubot
Re: if a=2b^3/c what happens to c when a is halved and b is [#permalink]
27 May 2007, 09:36
Moderators:
Bunuel
Math Expert
92902 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions