GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 21 Aug 2018, 03:21

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.

Close

Request Expert Reply

Confirm Cancel

If a cube of side length 24 units is cut into 512 smaller cubes of equ

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Manager
Manager
avatar
S
Joined: 14 Sep 2015
Posts: 65
Location: India
GMAT 1: 700 Q45 V40
GPA: 3.41
GMAT ToolKit User
If a cube of side length 24 units is cut into 512 smaller cubes of equ  [#permalink]

Show Tags

New post 23 May 2017, 13:25
3
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

69% (03:11) correct 31% (02:04) wrong based on 77 sessions

HideShow timer Statistics

If a cube of side length 24 units is cut into 512 smaller cubes of equal dimensions, then what is the ratio of the combined surface area of the smaller cubes and the surface area of the original cube?


A. 1:48
B. 3:32
C. 8:1
D. 32:3
E. 48:1
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 48074
Re: If a cube of side length 24 units is cut into 512 smaller cubes of equ  [#permalink]

Show Tags

New post 23 May 2017, 14:04
niteshwaghray wrote:
If a cube of side length 24 units is cut into 512 smaller cubes of equal dimensions, then what is the ratio of the combined surface area of the smaller cubes and the surface area of the original cube?


A. 1:48
B. 3:32
C. 8:1
D. 32:3
E. 48:1


512 = 8^3, which means that a side of a large cube will be divided into 8 parts giving the side lengths of smaller cubes as 24/8 = 3.

The combined surface area of the smaller cubes = 512*(6*3^2);

The surface area of the original cube = 6*24^2 (number of faces * area of a face).

\(Ratio = \frac{512*6*3^2}{6*24^2}=\frac{8^3*3^2}{6*8^2*3^2}=8\).

Answer: C.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Manager
Manager
User avatar
S
Joined: 24 Dec 2016
Posts: 82
Location: India
Concentration: Finance, General Management
WE: Information Technology (Computer Software)
CAT Tests
Re: If a cube of side length 24 units is cut into 512 smaller cubes of equ  [#permalink]

Show Tags

New post 24 May 2017, 00:00
Bunuel wrote:
niteshwaghray wrote:
If a cube of side length 24 units is cut into 512 smaller cubes of equal dimensions, then what is the ratio of the combined surface area of the smaller cubes and the surface area of the original cube?


A. 1:48
B. 3:32
C. 8:1
D. 32:3
E. 48:1


512 = 8^3, which means that a side of a large cube will be divided into 8 parts giving the side lengths of smaller cubes as 24/8 = 3.

The combined surface area of the smaller cubes = 512*(6*3^2);

The surface area of the original cube = 6*24^2 (number of faces * area of a face).

\(Ratio = \frac{512*6*3^2}{6*24^2}=\frac{8^3*3^2}{6*8^2*3^2}=8\).

Answer: C.



Hi Bunuel,

I'm having a little trouble understanding the highlighted part. could you please explain that a bit ?
Thanks in advance.
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 48074
If a cube of side length 24 units is cut into 512 smaller cubes of equ  [#permalink]

Show Tags

New post 24 May 2017, 00:47
1
Shruti0805 wrote:
Bunuel wrote:
niteshwaghray wrote:
If a cube of side length 24 units is cut into 512 smaller cubes of equal dimensions, then what is the ratio of the combined surface area of the smaller cubes and the surface area of the original cube?


A. 1:48
B. 3:32
C. 8:1
D. 32:3
E. 48:1


512 = 8^3, which means that a side of a large cube will be divided into 8 parts giving the side lengths of smaller cubes as 24/8 = 3.

The combined surface area of the smaller cubes = 512*(6*3^2);

The surface area of the original cube = 6*24^2 (number of faces * area of a face).

\(Ratio = \frac{512*6*3^2}{6*24^2}=\frac{8^3*3^2}{6*8^2*3^2}=8\).

Answer: C.



Hi Bunuel,

I'm having a little trouble understanding the highlighted part. could you please explain that a bit ?
Thanks in advance.


Check the image:

Image

The cube above is made of 8*8*8 = 512 little cubes. Notice that the sides of the cubes are divided by 8 equal parts.

Hope it helps.

Attachment:
cube.png
cube.png [ 280.71 KiB | Viewed 2454 times ]

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Manager
Manager
avatar
B
Joined: 21 Feb 2017
Posts: 79
GMAT ToolKit User
Re: If a cube of side length 24 units is cut into 512 smaller cubes of equ  [#permalink]

Show Tags

New post 27 May 2017, 04:57
Bunuel wrote:
niteshwaghray wrote:
If a cube of side length 24 units is cut into 512 smaller cubes of equal dimensions, then what is the ratio of the combined surface area of the smaller cubes and the surface area of the original cube?


A. 1:48
B. 3:32
C. 8:1
D. 32:3
E. 48:1


512 = 8^3, which means that a side of a large cube will be divided into 8 parts giving the side lengths of smaller cubes as 24/8 = 3.

The combined surface area of the smaller cubes = 512*(6*3^2);

The surface area of the original cube = 6*24^2 (number of faces * area of a face).

\(Ratio = \frac{512*6*3^2}{6*24^2}=\frac{8^3*3^2}{6*8^2*3^2}=8\).

Answer: C.

Hi, can you please provide link for such examples for practice?

Sent from my XT1663 using GMAT Club Forum mobile app
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 48074
Re: If a cube of side length 24 units is cut into 512 smaller cubes of equ  [#permalink]

Show Tags

New post 27 May 2017, 05:27
goalMBA1990 wrote:
Bunuel wrote:
niteshwaghray wrote:
If a cube of side length 24 units is cut into 512 smaller cubes of equal dimensions, then what is the ratio of the combined surface area of the smaller cubes and the surface area of the original cube?


A. 1:48
B. 3:32
C. 8:1
D. 32:3
E. 48:1


512 = 8^3, which means that a side of a large cube will be divided into 8 parts giving the side lengths of smaller cubes as 24/8 = 3.

The combined surface area of the smaller cubes = 512*(6*3^2);

The surface area of the original cube = 6*24^2 (number of faces * area of a face).

\(Ratio = \frac{512*6*3^2}{6*24^2}=\frac{8^3*3^2}{6*8^2*3^2}=8\).

Answer: C.

Hi, can you please provide link for such examples for practice?

Sent from my XT1663 using GMAT Club Forum mobile app


Similar questions to practice:
https://gmatclub.com/forum/m01-183522.html (GMAT Club)
https://gmatclub.com/forum/there-is-a-r ... 96312.html (Veritas Prep)
https://gmatclub.com/forum/cubes-with-e ... 93391.html
http://gmatclub.com/forum/if-a-4-cm-cub ... 07843.html (GMAT Club)
http://gmatclub.com/forum/a-large-cube- ... 10256.html
http://gmatclub.com/forum/64-small-iden ... 51009.html
http://gmatclub.com/forum/the-entire-ex ... 55955.html (Manhattan GMAT)
http://gmatclub.com/forum/a-big-cube-is ... 99424.html
http://gmatclub.com/forum/a-large-solid ... 51096.html
http://gmatclub.com/forum/a-wooden-cube ... 62570.html
https://gmatclub.com/forum/a-cube-of-si ... 48513.html
https://gmatclub.com/forum/a-certain-cl ... 67230.html (GMAT Prep)
https://gmatclub.com/forum/a-cube-has-a ... 09376.html
https://gmatclub.com/forum/a-cube-is-pa ... 80789.html (Data Sufficiency)
https://gmatclub.com/forum/a-certain-cu ... 63928.html

3-D Geometry Questions to practice: http://gmatclub.com/forum/3-d-geometry- ... 71024.html

Hope it helps.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Director
Director
avatar
S
Joined: 21 Mar 2016
Posts: 534
Reviews Badge
Re: If a cube of side length 24 units is cut into 512 smaller cubes of equ  [#permalink]

Show Tags

New post 27 May 2017, 11:25
1
Shruti0805 wrote:
Bunuel wrote:
niteshwaghray wrote:
If a cube of side length 24 units is cut into 512 smaller cubes of equal dimensions, then what is the ratio of the combined surface area of the smaller cubes and the surface area of the original cube?


A. 1:48
B. 3:32
C. 8:1
D. 32:3
E. 48:1


512 = 8^3, which means that a side of a large cube will be divided into 8 parts giving the side lengths of smaller cubes as 24/8 = 3.

The combined surface area of the smaller cubes = 512*(6*3^2);

The surface area of the original cube = 6*24^2 (number of faces * area of a face).

\(Ratio = \frac{512*6*3^2}{6*24^2}=\frac{8^3*3^2}{6*8^2*3^2}=8\).

Answer: C.



Hi Bunuel,

I'm having a little trouble understanding the highlighted part. could you please explain that a bit ?
Thanks in advance.



let me explain..

24 units of each side.. so volume = 24 * 24 * 24...
divide this by 512...
24 * 24 *24/ 512 = 27...
implies volume of each cube is 3..

rest is understandable... thanks,,,
Manager
Manager
User avatar
S
Joined: 24 Dec 2016
Posts: 82
Location: India
Concentration: Finance, General Management
WE: Information Technology (Computer Software)
CAT Tests
Re: If a cube of side length 24 units is cut into 512 smaller cubes of equ  [#permalink]

Show Tags

New post 28 May 2017, 21:00
Awesome, understood. Thank you mohshu !
Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 7776
Premium Member
Re: If a cube of side length 24 units is cut into 512 smaller cubes of equ  [#permalink]

Show Tags

New post 09 Jul 2018, 05:13
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Re: If a cube of side length 24 units is cut into 512 smaller cubes of equ &nbs [#permalink] 09 Jul 2018, 05:13
Display posts from previous: Sort by

If a cube of side length 24 units is cut into 512 smaller cubes of equ

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Events & Promotions

PREV
NEXT


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.