It is currently 13 Dec 2017, 11:03

Decision(s) Day!:

CHAT Rooms | Ross R1 | Kellogg R1 | Darden R1 | Tepper R1


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.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

20! + 21 is NOT a multiple of which of the following?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Manager
Manager
User avatar
G
Joined: 07 Jun 2017
Posts: 177

Kudos [?]: 102 [0], given: 59

Location: India
Concentration: Technology, General Management
GMAT 1: 660 Q46 V38
GPA: 3.6
WE: Information Technology (Computer Software)
GMAT ToolKit User
20! + 21 is NOT a multiple of which of the following? [#permalink]

Show Tags

New post 18 Oct 2017, 01:47
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

75% (00:21) correct 25% (00:19) wrong based on 32 sessions

HideShow timer Statistics

\(20! + 21\) is NOT a multiple of which of the following?

I. \(21\)

II. \(7\)

III. \(2\)

A. I only
B. III only
C. I and II
D. I and III
E. I, II, and III
[Reveal] Spoiler: OA

_________________

Regards,
Naveen
email: nkmungila@gmail.com
Please press kudos if you like this post

Kudos [?]: 102 [0], given: 59

Senior Manager
Senior Manager
User avatar
G
Joined: 19 Apr 2016
Posts: 276

Kudos [?]: 197 [0], given: 59

Location: India
GMAT 1: 570 Q48 V22
GMAT 2: 640 Q49 V28
GPA: 3.5
WE: Web Development (Computer Software)
Re: 20! + 21 is NOT a multiple of which of the following? [#permalink]

Show Tags

New post 18 Oct 2017, 02:00
B

Cz in case I 21 can be taken common from 21 and 20! And in case of II 7 can be taken common from 21 and 20!

Sent from my Redmi Note 4 using GMAT Club Forum mobile app

Last edited by 0akshay0 on 18 Oct 2017, 02:25, edited 1 time in total.

Kudos [?]: 197 [0], given: 59

BSchool Thread Master
User avatar
G
Joined: 15 May 2017
Posts: 167

Kudos [?]: 52 [0], given: 7

Concentration: Operations
Schools: Broad '20 (M)
GMAT 1: 760 Q49 V44
GPA: 3
WE: Supply Chain Management (Energy and Utilities)
Reviews Badge
Re: 20! + 21 is NOT a multiple of which of the following? [#permalink]

Show Tags

New post 18 Oct 2017, 02:21
B, III only.

III is pretty easy.
The product of 20! will be even, so adding 21 to it makes it odd. Hence, not a product of 2.

I and II are a little trickier
The product of 20! will be divisible by 7 and 21, as both of those quantities can be pulled out of the factors of 20!. (i.e. 7 and 14*3 give us what we need) Adding 21 to 20! keeps those same factors, since 21 is divisible by both 7 and 21.

This means 7 and 21 are both factors of "20!+21" leaving only 2 as a non factor

Kudos [?]: 52 [0], given: 7

Re: 20! + 21 is NOT a multiple of which of the following?   [#permalink] 18 Oct 2017, 02:21
Display posts from previous: Sort by

20! + 21 is NOT a multiple of which of the following?

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


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

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.