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

It is currently 19 Oct 2014, 20:43

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

How many zeros does 135^19 x 42^17 end with?

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 28 Jan 2011
Posts: 24
Followers: 1

Kudos [?]: 3 [0], given: 15

How many zeros does 135^19 x 42^17 end with? [#permalink] New post 07 Sep 2013, 02:56
00:00
A
B
C
D
E

Difficulty:

  5% (low)

Question Stats:

75% (01:02) correct 25% (00:31) wrong based on 16 sessions
How many zeros does 135^19 x 42^17 end with?

(a) 0
(b) 2
(c) 5
(d) 13
(e) 17
[Reveal] Spoiler: OA
Manager
Manager
User avatar
Joined: 20 Jul 2012
Posts: 140
Location: India
WE: Information Technology (Computer Software)
Followers: 1

Kudos [?]: 4 [0], given: 316

GMAT ToolKit User CAT Tests
Re: How many zeros does 135^19 x 42^17 end with? [#permalink] New post 07 Sep 2013, 04:45
salsal wrote:
How many zeros does 135^19 x 42^17 end with?

(a) 0
(b) 2
(c) 5
(d) 13
(e) 17

135=5x3^3 this implies
135^19=5^19x(3^3)^19..
similarly 42=2x3x7
42^17=2^17x3^17x7^17

we know to get zero we need 2 and 5... and we have 19 5's and 17 2's ...thus we can get 17 10's
_________________

Preparing for another shot...

Manager
Manager
avatar
Joined: 30 May 2013
Posts: 193
Location: India
Concentration: Entrepreneurship, General Management
GPA: 3.82
Followers: 0

Kudos [?]: 27 [0], given: 72

GMAT ToolKit User
Re: How many zeros does 135^19 x 42^17 end with? [#permalink] New post 07 Sep 2013, 05:18
salsal wrote:
How many zeros does 135^19 x 42^17 end with?

(a) 0
(b) 2
(c) 5
(d) 13
(e) 17



To know the zeros we need to know how many 10's are there for this need to find number of 2s and 5s ( 2 * 5 = 10)

135 = (5 x 3 ^3)^19 So Number of 5s are = 19
42 = (2x7x3)^17 so number of 2s = 17

So tot number of 10s in this number is (17-> 2s x 17-> 5s)

So answer is 17
Re: How many zeros does 135^19 x 42^17 end with?   [#permalink] 07 Sep 2013, 05:18
    Similar topics Author Replies Last post
Similar
Topics:
3 Experts publish their posts in the topic How many zeros are the end of ? vomhorizon 2 15 Nov 2012, 06:23
18 Experts publish their posts in the topic How many zeros does 100! end with? AndreG 14 07 Sep 2010, 12:41
Experts publish their posts in the topic How many zeros does 100! end with? (anybody know a nifty way irishspring 8 25 May 2008, 10:56
How many zeroes does 100! end with? a) 20 b) 24 c) 25 d) 30 shoonya 5 06 Aug 2006, 20:15
How many zeros does 100! end with? 20 24 25 30 32 from the Titleist 4 09 Dec 2004, 20:55
Display posts from previous: Sort by

How many zeros does 135^19 x 42^17 end with?

  Question banks Downloads My Bookmarks Reviews Important topics  


cron

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®.