NEW HERE? LEARN MORE
closeclose
Last visit was: 07 May 2024, 23:05 It is currently 07 May 2024, 23:05
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

A cylinder with a volume of 80π is altered so that its radius becomes

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 93082
Own Kudos [?]: 622048 [0]
Given Kudos: 81798
Send PM
CAT Tests Forum Quiz Mode
A cylinder with a volume of 80π is altered so that its radius becomes [#permalink] New post   29 Aug 2018, 01:41
Expert Reply
00:00
A
B
C
D
E

Difficulty:

15% (low)

Question Stats:

80% (01:24) correct 20% (00:45) wrong based on 56 sessions
Hide Show timer Statistics
A cylinder with a volume of 80π is altered so that its radius becomes half of the original radius and its height becomes double the original height. What is the volume of the altered cylinder?


A. \(160\pi\)

B. \(80\pi\)

C. \(40\pi\)

D. \(20\pi\)

E. \(10\pi\)
ShowHide Answer
Official Answer
C
User avatar
L
Archit3110
GMAT Club Legend
GMAT Club Legend
Joined: 18 Aug 2017
Status:You learn more from failure than from success.
Posts: 8027
Own Kudos [?]: 4116 [0]
Given Kudos: 242
Location: India
Concentration: Sustainability, Marketing
GMAT Focus 1:
545 Q79 V79 DI73
GPA: 4
WE:Marketing (Energy and Utilities)
Send PM
GMAT ToolKit User
Re: A cylinder with a volume of 80π is altered so that its radius becomes [#permalink] New post   29 Aug 2018, 01:50
A cylinder with a volume of 80π is altered so that its radius becomes half of the original radius and its height becomes double the original height. What is the volume of the altered cylinder?


A. 160π160π

B. 80π80π

C. 40π40π

D. 20π20π

E. 10π10π

original area : 3.14*r^2*h: 80*3.14
We can deduce
=> r^2*h: 80-----(1)

Area to be found: 3.14*(r/2)^2*2h -----(2)

substitute value from (1) in (2)
=> 3.14*(80*2)/4
=> answer 40 *3.14 option C
User avatar
D
PKN
Director
Director
Joined: 01 Oct 2017
Status:Learning stage
Posts: 825
Own Kudos [?]: 1323 [0]
Given Kudos: 41
WE:Supply Chain Management (Energy and Utilities)
Send PM
A cylinder with a volume of 80π is altered so that its radius becomes [#permalink] New post   29 Aug 2018, 02:01
Bunuel wrote:
A cylinder with a volume of 80π is altered so that its radius becomes half of the original radius and its height becomes double the original height. What is the volume of the altered cylinder?


A. \(160\pi\)

B. \(80\pi\)

C. \(40\pi\)

D. \(20\pi\)

E. \(10\pi\)


Given, \(r^'\)=\(\frac{r}{2}\) and \(h^'=2h\)
Volume of altered cylinder= \(\pi*r^'^2*h^'\)=\(\pi*(\frac{r}{2})^2*2h\)=\(\frac{1}{2}*\pi*r^2*h)\)=\(\frac{1}{2}*80\pi\)= \(40\pi\)

Ans. (C)
User avatar
P
JeffTargetTestPrep
Target Test Prep Representative
Joined: 04 Mar 2011
Status:Head GMAT Instructor
Affiliations: Target Test Prep
Posts: 3043
Own Kudos [?]: 6326 [0]
Given Kudos: 1646
Send PM
Forum Quiz Mode
Re: A cylinder with a volume of 80π is altered so that its radius becomes [#permalink] New post   03 Sep 2018, 19:05
Expert Reply
Bunuel wrote:
A cylinder with a volume of 80π is altered so that its radius becomes half of the original radius and its height becomes double the original height. What is the volume of the altered cylinder?


A. \(160\pi\)

B. \(80\pi\)

C. \(40\pi\)

D. \(20\pi\)

E. \(10\pi\)


We can let r = the original radius and h = the original height of the cylinder. So we have:

πr^2h = 80π

r^2h = 80

Now, we can make up a convenient number for r and calculate h. For example, we can let r = 4, so we have:

4^2h = 80

16h = 80

h = 5

Now, let’s halve the radius and double the height, so the new radius is 2 and the new height is 10. Therefore, the new volume is:

π x 2^2 x 10 = 40π

Answer: C
GMAT Club Bot
gmatclubot
Re: A cylinder with a volume of 80π is altered so that its radius becomes [#permalink]
03 Sep 2018, 19:05
Moderators:
Bunuel
Math Expert
93081 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