BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

the surface area of the cube?

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

the surface area of the cube?

by sanju09 » Fri Nov 04, 2011 4:55 am
The ratio of the number of cubic units in the volume of a cube to the number of square units in the surface area of the cube is 2:3. What is the surface area of the cube?
(A) 16 square units
(B) 24 square units
(C) 64 square units
(D) 96 square units
(E) 144 square units
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Source: — Problem Solving |
User avatar
Community Manager
Posts: 1060
Joined: Fri May 13, 2011 6:46 am
Location: Utrecht, The Netherlands
Thanked: 318 times
Followed by:52 members

by neelgandham » Fri Nov 04, 2011 5:00 am
Volume of a cube of side a = a*a*a cubic units
Surface area of the same cude = 6*a*a square units

From the question (a*a*a)/(6*a*a) = 2/3 => a/6=2/3 => a = 4
Surface area of the same cude = 6*a*a square units = [spoiler]6*4*4 = 96 square units[/spoiler] IMO Option D
Anil Gandham
Welcome to BEATtheGMAT | Photography | Getting Started | BTG Community rules | MBA Watch
Check out GMAT Prep Now's online course at https://www.gmatprepnow.com/
Top

GMAT/MBA Expert

User avatar
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

by Anurag@Gurome » Fri Nov 04, 2011 5:51 am
sanju09 wrote:The ratio of the number of cubic units in the volume of a cube to the number of square units in the surface area of the cube is 2:3. What is the surface area of the cube?
(A) 16 square units
(B) 24 square units
(C) 64 square units
(D) 96 square units
(E) 144 square units
Let each side of the cube = s units
Then volume of cube = s^3
Surface area of cube = 6s^2
Volume of cube : Surface area of cube = s^3 : 6s^2 = 2 : 3
s : 6 = 2 : 3 implies s = 4
Therefore, Surface area of cube = 6 * (4 ^ 2) = 6 * 16 = 96 sq units

The correct answer is D.
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/
Top
User avatar
Master | Next Rank: 500 Posts
Posts: 416
Joined: Tue Aug 30, 2011 2:18 pm
Location: Delhi, India
Thanked: 13 times
Followed by:9 members

by vaibhavgupta » Sat Nov 05, 2011 8:53 am
sanju09 wrote:The ratio of the number of cubic units in the volume of a cube to the number of square units in the surface area of the cube is 2:3. What is the surface area of the cube?
(A) 16 square units
(B) 24 square units
(C) 64 square units
(D) 96 square units
(E) 144 square units
First looked at ratios. all of them divisible by 3 are to be left.
then chose d cos the other one has to be a cube!

Hence D it is!
If OA is A, IMO B
If OA is B, IMO C
If OA is C, IMO D
If OA is D, IMO E
If OA is E, IMO A

FML!! :/
Top
Post new topic Post Reply
• Page 1 of 1