NEW HERE? LEARN MORE
closeclose
Last visit was: 26 Apr 2024, 05:48 It is currently 26 Apr 2024, 05:48
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 right circular cylinder’s radius is halved and its height doubled

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92933
Own Kudos [?]: 619156 [1]
Given Kudos: 81609
Send PM
CAT Tests Forum Quiz Mode
If a right circular cylinder’s radius is halved and its height doubled [#permalink] New post   19 Sep 2018, 21:51
1
Kudos
Expert Reply
00:00
A
B
C
D
E

Difficulty:

15% (low)

Question Stats:

82% (00:54) correct 18% (00:55) wrong based on 61 sessions
Hide Show timer Statistics
If a right circular cylinder’s radius is halved and its height doubled, by what percent will the volume increase or decrease?

(A) 50% decrease
(B) 0%
(C) 25% increase
(D) 50% increase
(E) 100% increase
ShowHide Answer
Official Answer
A
User avatar
G
GmatDaddy
Retired Moderator
Joined: 11 Aug 2016
Posts: 335
Own Kudos [?]: 351 [1]
Given Kudos: 97
Send PM
Reviews Badge
Re: If a right circular cylinder’s radius is halved and its height doubled [#permalink] New post   19 Sep 2018, 22:52
1
Kudos
Bunuel wrote:
If a right circular cylinder’s radius is halved and its height doubled, by what percent will the volume increase or decrease?

(A) 50% decrease
(B) 0%
(C) 25% increase
(D) 50% increase
(E) 100% increase


Volume of Right Circular Cylinder of radius r and height h
V=\(\pi*r^2*h\)

New Height \(H=2h\)
New Radius \(R=\frac{r}{2}\)

New Volume
\(V'=\pi*R^2*H\)
\(V'=\pi*\frac{(r^2)}{4}*2h\)
\(V'=\frac{V}{2}\)
Hence the volume decreases by V/2

Answeer: A
User avatar
L
GMATinsight
GMAT Club Legend
GMAT Club Legend
Joined: 08 Jul 2010
Status:GMAT/GRE Tutor l Admission Consultant l On-Demand Course creator
Posts: 5962
Own Kudos [?]: 13391 [1]
Given Kudos: 124
Location: India
GMAT: QUANT+DI EXPERT
Schools: IIM (A) ISB '24
GMAT 1: 750 Q51 V41
WE:Education (Education)
Send PM
Reviews Badge
If a right circular cylinder’s radius is halved and its height doubled [#permalink] New post   20 Sep 2018, 04:09
1
Kudos
Expert Reply
Bunuel wrote:
If a right circular cylinder’s radius is halved and its height doubled, by what percent will the volume increase or decrease?

(A) 50% decrease
(B) 0%
(C) 25% increase
(D) 50% increase
(E) 100% increase


Volume of the Cylinder \(= π*r^2*h\)

New Volume \(= π*(\frac{r}{2})^2*(2h) = \frac{π*r^2*h}{2}\)

i.e. New Volume is half of previous volume i.e. Volume decreased by 50%

Answer: Option A
User avatar
P
LeoN88
BSchool Moderator
Joined: 08 Dec 2013
Posts: 686
Own Kudos [?]: 516 [0]
Given Kudos: 227
Location: India
Concentration: Nonprofit, Sustainability
Schools: ISB '23
GMAT 1: 630 Q47 V30
WE:Operations (Non-Profit and Government)
Send PM
Reviews Badge
Re: If a right circular cylinder’s radius is halved and its height doubled [#permalink] New post   25 May 2019, 19:15
Bunuel wrote:
If a right circular cylinder’s radius is halved and its height doubled, by what percent will the volume increase or decrease?

(A) 50% decrease
(B) 0%
(C) 25% increase
(D) 50% increase
(E) 100% increase


Original volume= PI(r^2)h
New Volume= PI(r^2)(2h)/4 = PI(r^2)(h)/2 which is basically 1/2 of original volume. So, 50% decrease. A
GMAT Club Bot
gmatclubot
Re: If a right circular cylinder’s radius is halved and its height doubled [#permalink]
25 May 2019, 19:15
Moderators:
Bunuel
Math Expert
92931 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