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

It is currently 17 Jul 2018, 20:21

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

u=?

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

Hide Tags

Expert Post
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 5839
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
u=? [#permalink]

Show Tags

New post 25 Jul 2016, 19:40
00:00
A
B
C
D
E

Difficulty:

  25% (medium)

Question Stats:

67% (00:29) correct 33% (00:47) wrong based on 149 sessions

HideShow timer Statistics

u=?
1) |u|+|v|=0
2) u^2+v^2=0

*An answer will be posted in 2 days

_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Manager
Manager
avatar
Joined: 07 Jul 2016
Posts: 79
GPA: 4
u=? [#permalink]

Show Tags

New post 26 Jul 2016, 11:12
1
MathRevolution wrote:
u=?


\(\textbf{1) }\vert u \vert +\vert v\vert =0\)

The minimum result of the absolute value operator is 0. There is a single input for this: 0.

\(u = v = 0\)

Sufficient

\(\textbf{2) }u^2+v^2=0\)

The minimum result of squaring a number is 0 (barring complex numbers). There is a single input for this: 0.

\(u = v = 0\)

Sufficient

(D) each statement alone is sufficient


Note that the answer would change if negative values could be obtained from either function.
_________________

Please press +1 Kudos if this post helps.

Senior Manager
Senior Manager
avatar
B
Joined: 20 Feb 2015
Posts: 421
Concentration: Strategy, General Management
Re: u=? [#permalink]

Show Tags

New post 27 Jul 2016, 04:13
MathRevolution wrote:
u=?
1) |u|+|v|=0
2) u^2+v^2=0

*An answer will be posted in 2 days



1) |u|+|v|=0
same as
(+ve value) + ( +ve value) = 0
only possible
when u and v are 0
therefore sufficient.

2) u^2+v^2=0
same as above
+ve + +ve = 0
sufficient.

D
1 KUDOS received
Current Student
User avatar
Joined: 18 Oct 2014
Posts: 880
Location: United States
GMAT 1: 660 Q49 V31
GPA: 3.98
GMAT ToolKit User
Re: u=? [#permalink]

Show Tags

New post 27 Jul 2016, 18:01
1
MathRevolution wrote:
u=?
1) |u|+|v|=0
2) u^2+v^2=0

*An answer will be posted in 2 days


1) |u|+|v|=0
|u|=-|v|

how can a positive value be equal to -ve value. Only when u=v=0
Sufficient.

2) u^2+v^2=0
u^2= -v^2

u^2 will always be +ve and it can not be equal to -ve value. Its possible only when u=v=0
Sufficient

Both statements are sufficient independently.

D is the answer
_________________

I welcome critical analysis of my post!! That will help me reach 700+

Expert Post
Top Contributor
CEO
CEO
User avatar
P
Joined: 12 Sep 2015
Posts: 2633
Location: Canada
Re: u=? [#permalink]

Show Tags

New post 28 Jul 2016, 07:51
Top Contributor
MathRevolution wrote:
u = ?

1) |u| + |v| = 0
2) u² + v² = 0



Target question: What is the value of u?

Statement 1: |u| + |v| = 0
IMPORTANT: |k| is always greater than or equal to 0

So, |u| = some number greater than or equal to 0 AND |v| = some number greater than or equal to 0
So, statement 1 basically says: (some number greater than or equal to 0) + (some number greater than or equal to 0) = 0
This is possible ONLY IF each value is equal to zero.
So, |v| = 0 and |u| = 0, which means u = 0
Since we can answer the target question with certainty, statement 1 is SUFFICIENT

Statement 2: u² + v² = 0
IMPORTANT: k² is always greater than or equal to 0

So, u² = some number greater than or equal to 0 AND v² = some number greater than or equal to 0
So, statement 2 basically says: (some number greater than or equal to 0) + (some number greater than or equal to 0) = 0
This is possible ONLY IF each value is equal to zero.
So, v² = 0 and u² = 0, which means u = 0
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer =

RELATED VIDEOS



_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Expert Post
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 5839
GMAT 1: 760 Q51 V42
GPA: 3.82
Premium Member
Re: u=? [#permalink]

Show Tags

New post 31 Jul 2016, 08:46
There are 2 variables in the original condition and there is a high chance that C is the correct answer. Using con 1) and con 2), we get u=v=0. Hence the correct answer is D.
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Non-Human User
User avatar
Joined: 09 Sep 2013
Posts: 7275
Premium Member
Re: u=? [#permalink]

Show Tags

New post 17 Aug 2017, 08:25
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: u=?   [#permalink] 17 Aug 2017, 08:25
Display posts from previous: Sort by

u=?

  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®.