NEW HERE? LEARN MORE
closeclose
It is currently 11 Dec 2023, 08:42
Register
GMAT Classic Tests
GMAT Focus Tests
Decision Tracker
My Rewards
New posts
New comers' posts

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.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel

Find the number of zeroes in 1142! × 348! × 17!

5 posts Go to First Unread Post
Print view
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
SORT BY:
Date
Kudos
User avatar
L
saswata4s
Current Student
Joined: 27 May 2014
Posts: 427
GMAT 1: 730 Q49 V41
GMAT ToolKit User
Find the number of zeroes in 1142! × 348! × 17! [#permalink] New post  Updated on: 27 Jan 2017, 02:53
1
Kudos
8
Bookmarks
00:00
A
B
C
D
E

Difficulty:

75% (hard)

Question Stats:

53% (02:04) correct 47% (02:59) wrong based on 129 sessions

Hide Show timer Statistics

Find the number of zeroes in 1142! × 348! × 17!.

(A) 369
(B) 370
(C) 371
(D) 375
(E) 385
ShowHide Answer
Official Answer
Official Answer and Stats are available only to registered users. Register/Login.

_________________
440 to 730: If I Can, You Can Too
Signature Read More

Originally posted by saswata4s on 27 Jan 2017, 01:22.
Last edited by saswata4s on 27 Jan 2017, 02:53, edited 3 times in total.
Most Helpful Reply
User avatar
L
CrackverbalGMAT
GMAT Club Legend
GMAT Club Legend
Joined: 03 Oct 2013
Affiliations: CrackVerbal
Posts: 4949
Location: India
Re: Find the number of zeroes in 1142! × 348! × 17! [#permalink] New post  27 Jan 2017, 02:57
3
Kudos
3
Bookmarks
Top Contributor
Hi sawata4s,
To find the number of zero’s in a factorial, we get to understand, “how we get tens (zero’s) in a factorial?”
We get 10 when we have a minimum of one “2” and one “5”,
10 = 2 * 5
2’s and 5’s in a combination will give us the number of 10’s,
For every “2” in a factorial we may not have a “5”, but for every “5” in a factorial we will have “2”,
So we can just find the number of five’s to evaluate the number of zero’s
There are multiple ways to do that,
you can see the below image for solving it,
So the answer is B.
Hope this helps
Attachments

factorial.png
factorial.png [ 10.04 KiB | Viewed 14788 times ]


_________________
Crackverbal Prep Team

www.crackverbal.com
Signature Read More
General Discussion
User avatar
L
chetan2u
Math Expert
Joined: 02 Aug 2009
Posts: 10442
Reviews Badge
Re: Find the number of zeroes in 1142! × 348! × 17! [#permalink] New post  27 Jan 2017, 02:12
3
Kudos
1
Bookmarks
Expert Reply
saswata4s wrote:
Find the number of zeroes in 1142! × 348! × 17!.

(A) 369
(B) 371
(C) 375
(D) 370
(E) 385


Hi,
Number of 0s will depend upon number of 5s..
1) number of 5s= \(\frac{1142}{5}+\frac{348}{5}+\frac{17}{5}\)=228+69+3=300..
2) number of 25s=\(\frac{1142}{25}+\frac{348}{25}+\frac{17}{25}\)=45+13=58..
3) number of 125s=\(\frac{1142}{125}+\frac{348}{125}+\frac{17}{125}\)=9+2=11..
4) number of 625s=\(\frac{1142}{625}+\frac{348}{625}+\frac{17}{625}\)=1..

Total number of 5s= 300+58+11+1=370

Ans 370..

It seems you have not put the choices in order and that is why 370 is in D choice and not B..
_________________
1. Absolute modulus:. 2. Fractions: 3. Percentage increase: 4. Combinations:
Signature Read More
User avatar
L
saswata4s
Current Student
Joined: 27 May 2014
Posts: 427
GMAT 1: 730 Q49 V41
GMAT ToolKit User
Re: Find the number of zeroes in 1142! × 348! × 17! [#permalink] New post  27 Jan 2017, 02:55
chetan2u wrote:
It seems you have not put the choices in order and that is why 370 is in D choice and not B..


I've updated the correct OA. Thanks for pointing out.

Cheers.
_________________
440 to 730: If I Can, You Can Too
Signature Read More
User avatar
L
Abhishek009
Board of Directors
Joined: 11 Jun 2011
Status:QA & VA Forum Moderator
Posts: 5894
Location: India
GPA: 3.5
WE:Business Development (Commercial Banking)
GMAT ToolKit User
Re: Find the number of zeroes in 1142! × 348! × 17! [#permalink] New post  19 Sep 2023, 07:32
saswata4s wrote:
Find the number of zeroes in 1142! × 348! × 17!.

(A) 369
(B) 370
(C) 371
(D) 375
(E) 385

1142 will have 228 + 45 + 9 + 1 = 283 zeo's
348 will have 69 + 13 + 2 = 84 zero's
17 will have 3 zeros

Hence, Total no of zero's will be 283 + 84 + 3 = 370 zero's, Answer must be (B)
_________________
Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )
Signature Read More
GMAT Club Bot
gmatclubot
Re: Find the number of zeroes in 1142! × 348! × 17! [#permalink]
19 Sep 2023, 07:32
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
Moderators:
Bunuel
Math Expert
90249 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3139 posts

cron

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions