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

 It is currently 23 Jan 2019, 00:13

### 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

## Events & Promotions

###### Events & Promotions in January
PrevNext
SuMoTuWeThFrSa
303112345
6789101112
13141516171819
20212223242526
272829303112
Open Detailed Calendar
• ### Key Strategies to Master GMAT SC

January 26, 2019

January 26, 2019

07:00 AM PST

09:00 AM PST

Attend this webinar to learn how to leverage Meaning and Logic to solve the most challenging Sentence Correction Questions.
• ### Free GMAT Number Properties Webinar

January 27, 2019

January 27, 2019

07:00 AM PST

09:00 AM PST

Attend this webinar to learn a structured approach to solve 700+ Number Properties question in less than 2 minutes.

# M61-18

Author Message
TAGS:

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6832
GMAT 1: 760 Q51 V42
GPA: 3.82

### Show Tags

18 Jun 2018, 04:04
00:00

Difficulty:

35% (medium)

Question Stats:

82% (01:47) correct 18% (02:37) wrong based on 11 sessions

### HideShow timer Statistics

If $$2^n+2^{n-2}=5120$$, then $$n=?$$

A. 8
B. 9
C. 10
D. 11
E. 12

_________________

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 Joined: 16 Aug 2015 Posts: 6832 GMAT 1: 760 Q51 V42 GPA: 3.82 Re M61-18 [#permalink] ### Show Tags 18 Jun 2018, 04:04 Official Solution: If $$2^n+2^{n-2}=5120$$, then $$n=?$$ A. 8 B. 9 C. 10 D. 11 E. 12 Factoring yields $$2^{n}+2^{n-2}=2^{2}2^{n-2}+2^{n-2}=(2^2+1)2^{n-2}=5*2^{n-2}=5120=5*1024$$. Therefore, $$2^{n-2}=1024=2^{10}$$ and $$n-2 = 10$$. It follows that $$n = 12$$. Answer: E _________________ 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"

Intern
Joined: 14 Jun 2018
Posts: 47
Location: India

### Show Tags

14 Sep 2018, 05:08
MathRevolution wrote:
If $$2^n+2^{n-2}=5120$$, then $$n=?$$

A. 8
B. 9
C. 10
D. 11
E. 12

Hello Can anyone please explain this question in a simpler manner? it would be of great help. Thank you!
Intern
Joined: 08 Aug 2018
Posts: 5

### Show Tags

25 Oct 2018, 03:43
I agree with Shri15kumar. The explanation is not clear. I got the answer correct but only because I guessed and I would really like to learn how to solve a problem like this. Thank you!
Re: M61-18 &nbs [#permalink] 25 Oct 2018, 03:43
Display posts from previous: Sort by

# M61-18

Moderators: chetan2u, Bunuel

 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®.