Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 25 Aug 2016, 01:27

### 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 June
Open Detailed Calendar

# If n is an integer, and 5^n > 4,000,000. What is the least possible

Author Message
TAGS:

### Hide Tags

Manager
Joined: 17 Aug 2009
Posts: 235
Followers: 5

Kudos [?]: 197 [0], given: 25

If n is an integer, and 5^n > 4,000,000. What is the least possible [#permalink]

### Show Tags

11 Jan 2010, 05:24
1
This post was
BOOKMARKED
00:00

Difficulty:

45% (medium)

Question Stats:

54% (02:04) correct 46% (01:07) wrong based on 42 sessions

### HideShow timer Statistics

If n is an integer, and 5^n > 4,000,000. What is the least possible value of n?

A) 7
B) 8
C) 9
D) 10
E) 11
[Reveal] Spoiler: OA
Joined: 20 Aug 2009
Posts: 311
Location: Tbilisi, Georgia
Schools: Stanford (in), Tuck (WL), Wharton (ding), Cornell (in)
Followers: 16

Kudos [?]: 133 [4] , given: 69

Re: If n is an integer, and 5^n > 4,000,000. What is the least possible [#permalink]

### Show Tags

11 Jan 2010, 06:22
4
KUDOS
1
This post was
BOOKMARKED
$$4,000,000 = 2^2*1,000,000 = 2^2*10^6=2^2*2^6*5^6 = 2^8*5^6$$

$$5^n>2^8*5^6$$

$$5^{n-6}>256$$

$$625=5^4>256$$

$$n-6=4$$

$$n=10$$
Manager
Joined: 27 Apr 2008
Posts: 190
Followers: 1

Kudos [?]: 65 [0], given: 1

Re: If n is an integer, and 5^n > 4,000,000. What is the least possible [#permalink]

### Show Tags

11 Jan 2010, 07:28
You can solve it with the same way you find LCM.

5 | 4,000,000
5 | 800,000
5 | 160,000
5 | 32,000
5 | 6,400
5 | 1,280
5| 256
5 | 56
5 | 11
2

We have 9 5's and 1x2. For $$5^n$$ to be bigger than 4,000,000, we therefore need n=10.
Intern
Joined: 17 Nov 2009
Posts: 37
Schools: University of Toronto, Mcgill, Queens
Followers: 0

Kudos [?]: 86 [0], given: 9

Re: If n is an integer, and 5^n > 4,000,000. What is the least possible [#permalink]

### Show Tags

14 Feb 2010, 10:51
shalva wrote:
$$4,000,000 = 2^2*1,000,000 = 2^2*10^6=2^2*2^6*5^6 = 2^8*5^6$$

$$5^n>2^8*5^6$$

$$5^{n-6}>256$$

$$625=5^4>256$$

$$n-6=4$$

$$n=10$$

nice approach. What is OA?
_________________

--Action is the foundational key to all success.

CEO
Status: Nothing comes easy: neither do I want.
Joined: 12 Oct 2009
Posts: 2795
Location: Malaysia
Concentration: Technology, Entrepreneurship
Schools: ISB '15 (M)
GMAT 1: 670 Q49 V31
GMAT 2: 710 Q50 V35
Followers: 220

Kudos [?]: 1509 [0], given: 235

Re: If n is an integer, and 5^n > 4,000,000. What is the least possible [#permalink]

### Show Tags

14 Feb 2010, 12:15
IMO D -10

$$5^n > 5^6 * 4 * 2^6$$
$$5^n > 5^6 * 2^8$$
$$5^n > 5^6 * 256$$
$$5^n > 5^6 * 5^3 * \frac{256}{125}$$
$$5^n > 5^9* \frac{256}{125}$$ since $$\frac{256}{125}< 5$$

n = 10
_________________

Fight for your dreams :For all those who fear from Verbal- lets give it a fight

Money Saved is the Money Earned

Jo Bole So Nihaal , Sat Shri Akaal

GMAT Club Premium Membership - big benefits and savings

Gmat test review :
http://gmatclub.com/forum/670-to-710-a-long-journey-without-destination-still-happy-141642.html

Re: If n is an integer, and 5^n > 4,000,000. What is the least possible   [#permalink] 14 Feb 2010, 12:15
Similar topics Replies Last post
Similar
Topics:
1 If n is an integer, then the least possible value of l31 - 4nl is 2 05 Jul 2016, 11:55
9 If x > 0, what is the least possible value for x + 1/x ? 8 20 Oct 2014, 07:09
5 What is the least possible product of 4 different integers 13 16 Mar 2011, 11:29
18 If n is an integer and 5^n > 4,000,000, what is the least 12 19 Feb 2012, 19:02
16 If n is an integer and 5^n > 4,000,000, what is the least po 5 01 Jul 2010, 13:13
Display posts from previous: Sort by

# If n is an integer, and 5^n > 4,000,000. What is the least possible

 Powered by phpBB © phpBB Group and phpBB SEO 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®.