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

It is currently 18 Apr 2014, 23:01

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Why????? If N is a positive integer, is the units digits of

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
Joined: 02 May 2006
Posts: 25
Followers: 0

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

Why????? If N is a positive integer, is the units digits of [#permalink] New post 27 Jul 2006, 14:55
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
Why?????

If N is a positive integer, is the units digits of N iqual to 0 (zero)


1) 14 and 35 are factors of N
2) N=(2^5)*(3^2)*(5^7)*(7^6)

Answer: D
Senior Manager
Senior Manager
User avatar
Joined: 07 Jul 2005
Posts: 406
Location: Sunnyvale, CA
Followers: 2

Kudos [?]: 2 [0], given: 0

GMAT Tests User
Re: DS - Units Digit [#permalink] New post 27 Jul 2006, 14:59
MANRED wrote:
Why?????

If N is a positive integer, is the units digits of N iqual to 0 (zero)


1) 14 and 35 are factors of N
2) N=(2^5)*(3^2)*(5^7)*(7^6)

Answer: D


Yes, D it is.
I. since 14 and 35 are factors, its LCM is : 2*7*5 = 70 ..Now, the min. value N can be have is 70 or 70*x (x being +ve integer) .. Implies units digit is 0.

II. N's value is given, so we can calculate if units digit is 0 or not.

D.
Manager
Manager
User avatar
Joined: 19 Apr 2006
Posts: 231
Followers: 1

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

GMAT Tests User
Re: DS - Units Digit [#permalink] New post 27 Jul 2006, 16:54
MANRED wrote:
Why?????

If N is a positive integer, is the units digits of N iqual to 0 (zero)


1) 14 and 35 are factors of N
2) N=(2^5)*(3^2)*(5^7)*(7^6)

Answer: D


Yes or No question...

1. If 14 and 35 are factors of N, we know that 14 = 2*7 and 35 = 5*7. If you multiply 2*5*7 = unit digit is equal to 0. Yes...Suff...

2. Since we are only interested in the units digit only,
2^5 = some number with unit digit of 2
3^2= 9
5^7= some number with unit digit of 5
7^6= some number with unit digit of 9
so 2*9*9*5 = leads to unit digit of 0... Yes... Suff..

D
SVP
SVP
Joined: 30 Mar 2006
Posts: 1741
Followers: 1

Kudos [?]: 18 [0], given: 0

GMAT Tests User
 [#permalink] New post 27 Jul 2006, 22:50
D

1) 14 and 35 are factors.

LCM of 14 and 35 = 70
hence the mininum number can be 70 and other number can be 70 * x

2)
Unit digit of 2^5 = 2
Unit digit of 3^2 = 9
Unit digit of 5^x = 5
Unit digit of 7^6 = 3

Unit digit of N = Unit digit of (2*9*5*3) = 0
  [#permalink] 27 Jul 2006, 22:50
    Similar topics Author Replies Last post
Similar
Topics:
New posts If the units digit of the three-digit positive integer k is Antmavel 3 16 Oct 2004, 23:06
New posts If N is a positive integer, is the units digit of N equal to showtime12 1 12 Nov 2007, 19:58
New posts 5 If N is a positive Integer, is the units digit of N equal to meaglesp345 3 20 Mar 2010, 13:57
New posts 2 Experts publish their posts in the topic If n is a positive integer, what is the units digit of n? fozzzy 3 15 Jun 2013, 22:14
New posts 2 Experts publish their posts in the topic If m and n are positive integers. What is the units digit of gepetow 2 23 Jul 2013, 14:05
Display posts from previous: Sort by

Why????? If N is a positive integer, is the units digits of

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

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®.