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

 It is currently 17 Aug 2018, 12:37

### 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

# If 5^(x + 1) − 5^x = 5^5(10^2), then what is the value of x?

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 47977
If 5^(x + 1) − 5^x = 5^5(10^2), then what is the value of x?  [#permalink]

### Show Tags

31 Jul 2018, 21:48
00:00

Difficulty:

15% (low)

Question Stats:

88% (01:02) correct 12% (02:09) wrong based on 26 sessions

### HideShow timer Statistics

If $$5^{(x + 1)} − 5^x = 5^5(10^2)$$, then what is the value of x?

A. 5
B. 6
C. 7
D. 8
E. 9

_________________
Manager
Joined: 17 Jan 2017
Posts: 137
Location: India
GPA: 4
WE: Information Technology (Computer Software)
Re: If 5^(x + 1) − 5^x = 5^5(10^2), then what is the value of x?  [#permalink]

### Show Tags

31 Jul 2018, 21:58
Bunuel wrote:
If $$5^{(x + 1)} − 5^x = 5^5(10^2)$$, then what is the value of x?

A. 5
B. 6
C. 7
D. 8
E. 9

5^{(x + 1)} − 5^x = 5^5(10^2)
5^x.5^1 - 5^x = 5^5(5^2.2^2)
5^x(5^1-1) = 5^7.2^2
5^x.2^2 = 5^7.2^2
By equating, we get
x = 7

Hence, C
_________________

Correct me If I'm wrong !! looking for valuable inputs

KUDOS please, if you like the post or if it helps !!

Director
Joined: 30 Jan 2015
Posts: 525
Location: India
Concentration: Operations, Marketing
GPA: 3.5
Re: If 5^(x + 1) − 5^x = 5^5(10^2), then what is the value of x?  [#permalink]

### Show Tags

31 Jul 2018, 21:59
+1 for C.

5^(x + 1) − 5^x = 5^5(10^2)
(5^x * 5) - 5^x = 5^5 * 5^2 * 2^2
5^x * ( 5 - 1) = 5^7 * 2^2
5^x * 2^2 = 5^7 * 2^2
5^x = 5^7
x = 7

Hence, C.
_________________

The few, the fearless !

Thanks

Senior Manager
Joined: 31 Oct 2013
Posts: 477
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
If 5^(x + 1) − 5^x = 5^5(10^2), then what is the value of x?  [#permalink]

### Show Tags

01 Aug 2018, 00:32
Bunuel wrote:
If $$5^{(x + 1)} − 5^x = 5^5(10^2)$$, then what is the value of x?

A. 5
B. 6
C. 7
D. 8
E. 9

Given

$$5^{(x + 1)} − 5^x = 5^5(10^2)$$

$$5^x 5^1 - 5^x = 5^5 5^2 2^2$$

$$5^x(5 - 1 ) = 5^7 2^2$$

$$5^x *4 = 5^7 *4$$

$$5^x = 5^7$$

x = 7

If 5^(x + 1) − 5^x = 5^5(10^2), then what is the value of x? &nbs [#permalink] 01 Aug 2018, 00:32
Display posts from previous: Sort by

# 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®.