A rectangular box has the dimensions 12 inches x 10 inches x 8 inches. What is the largest possible volume of a right cylinder that is placed inside the box?
OA: 200pie
Source: Manhattan GMAT Geometry 4th edition, pg. 49.
Geometry problem
This topic has expert replies
- LalaB
- Master | Next Rank: 500 Posts
- Posts: 425
- Joined: Wed Dec 08, 2010 9:00 am
- Thanked: 56 times
- Followed by:7 members
- GMAT Score:690
the largest volume is possible, if the height is 8, and the rest (10 and 12) are the legs.
so, the volume =5^2*8=25*8=200
so, the volume =5^2*8=25*8=200
Happy are those who dream dreams and are ready to pay the price to make them come true.(c)
In order to succeed, your desire for success should be greater than your fear of failure.(c)
In order to succeed, your desire for success should be greater than your fear of failure.(c)
-
- Junior | Next Rank: 30 Posts
- Posts: 10
- Joined: Thu May 12, 2011 12:47 pm
- Thanked: 1 times
GMAT/MBA Expert
- Anurag@Gurome
- GMAT Instructor
- Posts: 3835
- Joined: Fri Apr 02, 2010 10:00 pm
- Location: Milpitas, CA
- Thanked: 1854 times
- Followed by:523 members
- GMAT Score:770
Volume of cylinder = pi * r² * h.HG10 wrote:A rectangular box has the dimensions 12 inches x 10 inches x 8 inches. What is the largest possible volume of a right cylinder that is placed inside the box?
OA: 200pie
Source: Manhattan GMAT Geometry 4th edition, pg. 49.
For maximum volume, radius should be maximum because it has a square power.
This is possible if we take the base of cylinder as the base of the box which is 12*10.
Then the diameter is 10 for the cylinder, as it has to be lesser of 10 and 12.
Or radius is 10/2 = 5 and height is 8.
So volume is pi * 5² * 8 = 200pi.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)
Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)
Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
- Troika
- Master | Next Rank: 500 Posts
- Posts: 136
- Joined: Wed Apr 08, 2009 12:09 pm
- Thanked: 4 times
- Followed by:1 members
Guys, thank you for your responses.
I just have one question, i.e. if radius should me maximum for maximum volume, why select r=10/2, why not r=12/2 and h=10 instead of h=8?
I just have one question, i.e. if radius should me maximum for maximum volume, why select r=10/2, why not r=12/2 and h=10 instead of h=8?
The only battle you can loose, is the one you abandon.
- LalaB
- Master | Next Rank: 500 Posts
- Posts: 425
- Joined: Wed Dec 08, 2010 9:00 am
- Thanked: 56 times
- Followed by:7 members
- GMAT Score:690
u better try to draw ur desired figure. if u do so, u will find out that it is impossible to have two sides 10 and 12, and get 12/2,since the max value of ur side is 10.HG10 wrote:Guys, thank you for your responses.
I just have one question, i.e. if radius should me maximum for maximum volume, why select r=10/2, why not r=12/2 and h=10 instead of h=8?
Happy are those who dream dreams and are ready to pay the price to make them come true.(c)
In order to succeed, your desire for success should be greater than your fear of failure.(c)
In order to succeed, your desire for success should be greater than your fear of failure.(c)
- Troika
- Master | Next Rank: 500 Posts
- Posts: 136
- Joined: Wed Apr 08, 2009 12:09 pm
- Thanked: 4 times
- Followed by:1 members
Thank you, LalaB and Anurag@Gurome for your solutions and explanations.
@LalaB, thanks for pointing out the dimensional limitations.
@LalaB, thanks for pointing out the dimensional limitations.
The only battle you can loose, is the one you abandon.