GMAT Question of the Day - Daily to your Mailbox; hard ones only

It is currently 17 Dec 2018, 01:59

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 in December
PrevNext
SuMoTuWeThFrSa
2526272829301
2345678
9101112131415
16171819202122
23242526272829
303112345
Open Detailed Calendar
  • 10 Keys to nail DS and CR questions

     December 17, 2018

     December 17, 2018

     06:00 PM PST

     07:00 PM PST

    Join our live webinar and learn how to approach Data Sufficiency and Critical Reasoning problems, how to identify the best way to solve each question and what most people do wrong.
  • R1 Admission Decisions: Estimated Decision Timelines and Chat Links for Major BSchools

     December 17, 2018

     December 17, 2018

     10:00 PM PST

     11:00 PM PST

    From Dec 5th onward, American programs will start releasing R1 decisions. Chat Rooms: We have also assigned chat rooms for every school so that applicants can stay in touch and exchange information/update during decision period.

How many of the factors of 42 are divisible by 3 ?

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 51258
How many of the factors of 42 are divisible by 3 ?  [#permalink]

Show Tags

New post 05 Nov 2018, 23:14
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

55% (00:53) correct 45% (00:43) wrong based on 64 sessions

HideShow timer Statistics

Director
Director
User avatar
P
Joined: 31 Oct 2013
Posts: 883
Concentration: Accounting, Finance
GPA: 3.68
WE: Analyst (Accounting)
Re: How many of the factors of 42 are divisible by 3 ?  [#permalink]

Show Tags

New post 05 Nov 2018, 23:56
Bunuel wrote:
How many of the factors of 42 are divisible by 3 ?

A. 2
B. 3
C. 4
D. 6
E. 8



Factors of 42 :

1 * 42
2 * 21
3*14
6*7


Among them only 42 , 21 , 6 , 3 are divisible by 3.

The best answer is C.
Manager
Manager
User avatar
S
Joined: 08 Sep 2008
Posts: 115
Location: India
Concentration: Operations, General Management
Schools: ISB '20
GPA: 3.8
WE: Operations (Transportation)
CAT Tests
Re: How many of the factors of 42 are divisible by 3 ?  [#permalink]

Show Tags

New post 06 Nov 2018, 00:01
1
Factor of 42: 2^1 *3^1 * 7^1 (total 8 factor)
1,2,3,6,7,14,21, and 42

Divisible by 3:
3,6,21,and 42
total:-4

Answer: C
_________________

Regards;
Vishal

+==========+
Kudos if it deserve....one...

Intern
Intern
avatar
B
Joined: 09 Oct 2018
Posts: 8
Re: How many of the factors of 42 are divisible by 3 ?  [#permalink]

Show Tags

New post 23 Nov 2018, 03:00
Does anyone know a shortcut to derive at "4" using the prime factorization? Or do we actually have to write down all the factors and just do the prime factorization to double-check that we have found all possible factors?
Manager
Manager
User avatar
B
Joined: 05 Oct 2017
Posts: 63
Location: India
Schools: GWU '21, Isenberg'21
CAT Tests
Re: How many of the factors of 42 are divisible by 3 ?  [#permalink]

Show Tags

New post 23 Nov 2018, 03:24
Method i used to drive at the correct answer is following

prime Factorization of 42 = 2^1 * 3^1 * 7^1

Now any factor of 42 will be divisible by 3 when it has 3 as its prime factor , means any factor of 42, should have power of 3 as 1 and 2 and 7 can have power as 0,1

3^1 * 2^0 * 7^0 (only 1 power of 3 and 0 zero power of 2 and 7 )= 3
3^1 * 2^1 * 7^0 (only 1 power of 3 and 2 zero power of 7 ) = 6
3^1 * 2^0 * 7^1 (only 1 power of 3 and 7 zero power of 2 ) =21
3^1 * 2^1 * 7^1 (all have 1 power each ) = 42
Correct Choice option is C
_________________

The Path is the Goal

Quant Mega Thread by Bunnel
WTF is “that” doing in my sentence? By VerbalNinja

GMAT Club Bot
Re: How many of the factors of 42 are divisible by 3 ? &nbs [#permalink] 23 Nov 2018, 03:24
Display posts from previous: Sort by

How many of the factors of 42 are divisible by 3 ?

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.