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

 It is currently 21 Aug 2018, 18:58

### 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

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

# Geometry

 new topic post reply Question banks Downloads My Bookmarks Reviews Important topics
Author Message
Intern
Joined: 02 Jan 2015
Posts: 8

### Show Tags

17 Jan 2015, 13:57
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

A cube has length x, a surface area y, and a volume z. Which of the following must be true?

A. xy/z - y/x = 0
B. x^2y/z - y/x = 0
C. xz/x^2y - x^2/xy = 0
D. x(√y)/√z - x^2/y = 0
E. (√z)/xy - (√y)/x^2 = 0

Is there a simpler way to solve this rather than taking individual value combinations and checking each option.

Regards,

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.
Director
Status: Tutor - BrushMyQuant
Joined: 05 Apr 2011
Posts: 612
Location: India
Concentration: Finance, Marketing
Schools: XLRI (A)
GMAT 1: 700 Q51 V31
GPA: 3
WE: Information Technology (Computer Software)

### Show Tags

17 Jan 2015, 21:57
1
We can solve it using units
If x is in m(meters) then y will be m^2 then z will be m^3

A cannot be true as m*m^2/m^3 - m^2/m.. first entity does not have a unit so you cannot subtract it from the second unit which has meter unit
B Can be true as it is meter - meter
C cannot be true : No unit - Meter unit
D cannot be true: √meter unit - no unit
E cannot be true: 1/meter*√meter unit - 1/meter unit

So, answer will be B

Hope it helps!
amidamani13 wrote:
A cube has length x, a surface area y, and a volume z. Which of the following must be true?

A. xy/z - y/x = 0
B. x^2y/z - y/x = 0
C. xz/x^2y - x^2/xy = 0
D. x(√y)/√z - x^2/y = 0
E. (√z)/xy - (√y)/x^2 = 0

Is there a simpler way to solve this rather than taking individual value combinations and checking each option.

Regards,

_________________

Ankit

Check my Tutoring Site -> Brush My Quant

GMAT Quant Tutor
How to start GMAT preparations?
How to Improve Quant Score?
Gmatclub Topic Tags
Check out my GMAT debrief

How to Solve :
Statistics || Reflection of a line || Remainder Problems || Inequalities

Intern
Joined: 02 Jan 2015
Posts: 8

### Show Tags

19 Jan 2015, 01:10
Thanks a ton...really helpful....

Regards,
Manager
Joined: 12 Jun 2016
Posts: 219
Location: India
WE: Sales (Telecommunications)

### Show Tags

06 May 2017, 22:25
Hello BrushMyQuant,

A very innovative way for solving indeed! Thanks for sharing. Hope solutions like this "Come" to me when I sit to solve.

Specially, even if I plugged in numbers (X=1, Y=6 and Z=1) Both B & C very true. Again I had to Pick (X=2, Y=24 and Z=8) to see that B is the only answer. It took me approximate 3 Mins to do this

Thanks again for this approach!

BrushMyQuant wrote:
We can solve it using units
If x is in m(meters) then y will be m^2 then z will be m^3

A cannot be true as m*m^2/m^3 - m^2/m.. first entity does not have a unit so you cannot subtract it from the second unit which has meter unit
B Can be true as it is meter - meter
C cannot be true : No unit - Meter unit
D cannot be true: √meter unit - no unit
E cannot be true: 1/meter*√meter unit - 1/meter unit

So, answer will be B

Hope it helps!
amidamani13 wrote:
A cube has length x, a surface area y, and a volume z. Which of the following must be true?

A. xy/z - y/x = 0
B. x^2y/z - y/x = 0
C. xz/x^2y - x^2/xy = 0
D. x(√y)/√z - x^2/y = 0
E. (√z)/xy - (√y)/x^2 = 0

Is there a simpler way to solve this rather than taking individual value combinations and checking each option.

Regards,

_________________

My Best is yet to come!

Director
Affiliations: GMATQuantum
Joined: 19 Apr 2009
Posts: 605

### Show Tags

07 May 2017, 07:24
1
Top Contributor

Hi amidamani13,

This is a poorly written GMAT question, and I am pretty certain that this is not an official GMAT question. If the GMAT writers created such a question they will make sure that the units are consistent so one could not just look at the dimensions of the answer choices and eliminate answers.

The image I have attached is a one of the official GMAT questions that came to my mind when I saw this question. It is a bit different and not terribly difficult but you will see that it is well written.

Cheers,
Dabral

--== Message from GMAT Club Team ==--

This is not a quality discussion. It has been retired.

If you would like to discuss this question please re-post it in the respective forum. Thank you!

To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative | Verbal Please note - we may remove posts that do not follow our posting guidelines. Thank you.

Attachments

gmat-cubequestion.png [ 66.01 KiB | Viewed 387 times ]

Re: Geometry &nbs [#permalink] 07 May 2017, 07:24
Display posts from previous: Sort by

# Geometry

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

# Events & Promotions

 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®.