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

 It is currently 16 Jan 2019, 02:11

### 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
• ### The winning strategy for a high GRE score

January 17, 2019

January 17, 2019

08:00 AM PST

09:00 AM PST

Learn the winning strategy for a high GRE score — what do people who reach a high score do differently? We're going to share insights, tips and strategies from data we've collected from over 50,000 students who used examPAL.
• ### Free GMAT Strategy Webinar

January 19, 2019

January 19, 2019

07:00 AM PST

09:00 AM PST

Aiming to score 760+? Attend this FREE session to learn how to Define your GMAT Strategy, Create your Study Plan and Master the Core Skills to excel on the GMAT.

# 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: 52130
If 5^(x + 1) − 5^x = 5^5(10^2), then what is the value of x?  [#permalink]

### Show Tags

31 Jul 2018, 20:48
00:00

Difficulty:

15% (low)

Question Stats:

84% (01:09) correct 16% (02:05) wrong based on 37 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

_________________
Senior Manager
Joined: 17 Jan 2017
Posts: 300
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, 20:58
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
_________________

Only those who risk going too far, can possibly find out how far one can go

SC Moderator
Joined: 30 Jan 2015
Posts: 724
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, 20:59
+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

Director
Joined: 31 Oct 2013
Posts: 951
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

31 Jul 2018, 23:32
1
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] 31 Jul 2018, 23:32
Display posts from previous: Sort by