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

It is currently 26 Apr 2019, 01:09

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

2^(x+y)/2^(x-y)=?

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

Hide Tags

 
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 7252
GMAT 1: 760 Q51 V42
GPA: 3.82
2^(x+y)/2^(x-y)=?  [#permalink]

Show Tags

New post 12 Jul 2016, 19:05
3
2
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

81% (00:47) correct 19% (01:02) wrong based on 275 sessions

HideShow timer Statistics

2^(x+y)/2^(x-y)=?
1) x=1
2) y=2

*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 $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Retired Moderator
avatar
G
Joined: 26 Nov 2012
Posts: 591
Re: 2^(x+y)/2^(x-y)=?  [#permalink]

Show Tags

New post 12 Jul 2016, 22:41
MathRevolution wrote:
2^(x+y)/2^(x-y)=?
1) x=1
2) y=2

*An answer will be posted in 2 days


Given 2^(x+y)/2^(x-y).

We can write it as 2^(x+y)-(x-y)

=> 2^2y

So Stat 2 : clearly this is Sufficient as y = 2.

Option B is correct.
Intern
Intern
avatar
Joined: 21 Dec 2015
Posts: 12
Re: 2^(x+y)/2^(x-y)=?  [#permalink]

Show Tags

New post 13 Jul 2016, 01:29
Lets solve the stem first

2(x+y)-(x-y) = 2^2y

Hence Option B satisfies it
Intern
Intern
avatar
Joined: 15 Apr 2014
Posts: 2
Re: 2^(x+y)/2^(x-y)=?  [#permalink]

Show Tags

New post 13 Jul 2016, 02:24
Solve the stem - you will get 2^2y
Hence B
Intern
Intern
User avatar
Joined: 21 May 2013
Posts: 5
GPA: 3
Re: 2^(x+y)/2^(x-y)=?  [#permalink]

Show Tags

New post 13 Jul 2016, 04:09
if GMAT will ask such questions then I'll score 800.


Sent from my iPhone using GMAT Club Forum mobile app
Current Student
User avatar
Joined: 18 Oct 2014
Posts: 836
Location: United States
GMAT 1: 660 Q49 V31
GPA: 3.98
GMAT ToolKit User
Re: 2^(x+y)/2^(x-y)=?  [#permalink]

Show Tags

New post 13 Jul 2016, 06:53
MathRevolution wrote:
2^(x+y)/2^(x-y)=?
1) x=1
2) y=2

*An answer will be posted in 2 days


2^(x+y)/2^(x-y)= 2^(x+y)- (x-y)= 2^2y

So, it depends on the value of y.

B is the answer
_________________
I welcome critical analysis of my post!! That will help me reach 700+
CEO
CEO
User avatar
V
Joined: 12 Sep 2015
Posts: 3595
Location: Canada
Re: 2^(x+y)/2^(x-y)=?  [#permalink]

Show Tags

New post 13 Jul 2016, 13:45
1
Top Contributor
MathRevolution wrote:
2^(x+y)/2^(x-y)=?

1) x=1
2) y=2


Target question: What is the value of 2^(x+y)/2^(x-y)?
This is a great candidate for rephrasing the target question.

Let's apply the division law, (x^a)/(x^b) = x^(a-b)
So, 2^(x+y)/2^(x-y) = 2^[(x+y) - (x-y)]
= 2^(2y)

We can now REPHRASE the target question...
REPHRASED target question: What is the value of 2^(2y)?

Statement 1: x = 1
This information has no bearing on the REPHRASED target question
So, statement 1 is NOT SUFFICIENT

Statement 2: y = 2
PERFECT.
This means that 2^(2y) = 2^4 = 16
Since we can answer the REPHRASED target question with certainty, statement 2 is SUFFICIENT

Answer =

RELATED VIDEOS



_________________
Test confidently with gmatprepnow.com
Image
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 7252
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: 2^(x+y)/2^(x-y)=?  [#permalink]

Show Tags

New post 14 Jul 2016, 21:23
If we modify the original condition and the question, we get 2^(x+y)/2(x-y)=? --> 2^((x+y)-(x-y))=2^2y. We only have to know y and the correct answer is B.


- Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.
_________________
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 $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 7252
GMAT 1: 760 Q51 V42
GPA: 3.82
2^x+y/2^x-y=?  [#permalink]

Show Tags

New post 31 Jan 2017, 02:57
\(2^x^+^y/2^x^-^y=?\)

1) x=1
2) y=2
_________________
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 $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Math Expert
User avatar
V
Joined: 02 Aug 2009
Posts: 7595
Re: 2^x+y/2^x-y=?  [#permalink]

Show Tags

New post 31 Jan 2017, 04:23
MathRevolution wrote:
\(2^x^+^y/2^x^-^y=?\)

1) x=1
2) y=2




\(2^x^+^y/2^x^-^y=\frac{2^x*2^y}{2^x}*2^y=2^{2y}\)

So we require to know only y..

Statement II gives us value of y..
Sufficient

B
_________________
Director
Director
User avatar
D
Joined: 05 Mar 2015
Posts: 999
2^x+y/2^x-y=?  [#permalink]

Show Tags

New post 01 Feb 2017, 07:36
MathRevolution wrote:
\(2^x^+^y/2^x^-^y=?\)

1) x=1
2) y=2



2^(x+y-(x-y))----{ as x^m/x^n = X^(m-n)}
=2^(x+y-x+y)
=2^2y=??

(1) x=1
no info on Y
insuff

(2) y=2
thus 2^2y = 2^4 =16
suff

Ans B
Director
Director
avatar
P
Joined: 14 Nov 2014
Posts: 624
Location: India
GMAT 1: 700 Q50 V34
GPA: 3.76
Re: 2^x+y/2^x-y=?  [#permalink]

Show Tags

New post 02 Feb 2017, 02:34
MathRevolution wrote:
\(2^x^+^y/2^x^-^y=?\)

1) x=1
2) y=2



2^(x+y-x+y)=2^2y
A-not suff
B-suff , as we know value of Y.

So B.
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 7252
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: 2^x+y/2^x-y=?  [#permalink]

Show Tags

New post 02 Feb 2017, 02:51
1
==> If you modify the original condition and the question, from \(2^x^+^y/2^x^-^y=2^x^+^y^-^(^x^-^y^)=2^x^+^y^-^x^+^y=2^2^y\), you only need to know y. From con 2) y=2, it is sufficient.

Therefore, the answer is B.
Answer: B
_________________
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 $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Moderator
avatar
V
Joined: 22 Jun 2014
Posts: 1112
Location: India
Concentration: General Management, Technology
GMAT 1: 540 Q45 V20
GPA: 2.49
WE: Information Technology (Computer Software)
GMAT ToolKit User
Re: 2^x+y/2^x-y=?  [#permalink]

Show Tags

New post 04 Feb 2017, 07:02
MathRevolution wrote:
\(2^x^+^y/2^x^-^y=?\)

1) x=1
2) y=2


\(2^x^+^y/2^x^-^y=?\) can be re-written as:

\(2^x * 2^y / 2^x * 2^{-y}\) =?

\(2^y / 2^{-y}\) = ?

\(2^{2y}\) =?

We now only need to know the value of one variable i.e. \(y\). Hence statement-2 is sufficient. Answer is B.
_________________
Director
Director
User avatar
V
Joined: 06 Jan 2015
Posts: 628
Location: India
Concentration: Operations, Finance
GPA: 3.35
WE: Information Technology (Computer Software)
Premium Member
Re: 2^x+y/2^x-y=?  [#permalink]

Show Tags

New post 31 Jul 2017, 08:01
1
Bunuel Can you please merge the above topic. :-)

https://gmatclub.com/forum/2-x-y-2-x-y-221942.html
_________________
आत्मनॊ मोक्षार्थम् जगद्धिताय च

Resource: GMATPrep RCs With Solution
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 54544
Re: 2^(x+y)/2^(x-y)=?  [#permalink]

Show Tags

New post 31 Jul 2017, 09:34
GMAT Club Bot
Re: 2^(x+y)/2^(x-y)=?   [#permalink] 31 Jul 2017, 09:34
Display posts from previous: Sort by

2^(x+y)/2^(x-y)=?

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


Copyright

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®.