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

It is currently 24 Sep 2018, 22:23

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

Is x divisible by 39?

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

Hide Tags

Senior Manager
Senior Manager
User avatar
P
Joined: 12 Feb 2015
Posts: 436
Premium Member CAT Tests
Is x divisible by 39?  [#permalink]

Show Tags

New post 16 Jun 2018, 01:34
9
00:00
A
B
C
D
E

Difficulty:

  95% (hard)

Question Stats:

25% (02:26) correct 75% (02:32) wrong based on 99 sessions

HideShow timer Statistics

Is x divisible by 39?
1. x divided by 65 results in a remainder of 7.
2. x divided by 36 results in a remainder of 15.

_________________

"Please hit :thumbup: +1 Kudos if you like this post" :student_man:

_________________
Manish :geek:

"Only I can change my life. No one can do it for me"

SVP
SVP
User avatar
P
Joined: 08 Jul 2010
Posts: 2363
Location: India
GMAT: INSIGHT
WE: Education (Education)
Reviews Badge
Re: Is x divisible by 39?  [#permalink]

Show Tags

New post 16 Jun 2018, 01:41
CAMANISHPARMAR wrote:
Is x divisible by 39?
1. x divided by 65 results in a remainder of 7.
2. x divided by 36 results in a remainder of 15.



Question: Is x divisible by 39?

A number is divisible by 39 when the number is divisible by 3 and 13 both because 39=3*13

Statement 1: x divided by 65 results in a remainder of 7.

i.e. x = 65a + 7

i.e. when x is divided by 13 then remainder is 7 again (because 65 is also divisible by 13)

hence, x is NOT divisible by 39

SUFFICIENT

Statement 2: x divided by 36 results in a remainder of 15

x = 36b + 15 = 3(12b + 5)

i.e. x = 15 or 51 or 87 (Not divisible by 39 or 195 (Divisible by 39)

NOT SUFFICIENT

Answer: Option A
_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Senior Manager
Senior Manager
User avatar
P
Joined: 12 Feb 2015
Posts: 436
Premium Member CAT Tests
Is x divisible by 39?  [#permalink]

Show Tags

New post Updated on: 01 Jul 2018, 00:32
4
Official Answer:- A

Is x divisible by 39?

Step 1: Analyze the Question
This is a Yes/No question. Unlike other remainder questions in which you can pick numbers, the remainders in the
statements would be very tedious and time-consuming to test multiple times individually, let alone to combine. Thus, there
must be a simpler way to determine divisibility. Whenever the numbers given are unwieldy, the easiest and most efficient
way to establish divisibility is to find the prime factors. In this case, 39 breaks down to 3 × 13, so for x to be divisible by
39, it must be divisible by both 3 and 13.

Step 2: Evaluate the Statements

Statement (1) gives the number 65. Consider that 65 is 5 × 13; one of the prime factors of 39 is present. For x to be divisible
by 13, the remainder itself must be a multiple of 13. The remainder 7 is not a multiple of 13, so it is impossible for x to be
divisible by 13 or 39. This makes the answer to the question always no, and Statement (1) is sufficient. Eliminate choices
(B), (C), and (E).

In evaluating Statement (2), you can use the same principle. The number 36 is divisible by 3, one of the necessary primes, so
the remainder must also be divisible by 3. The remainder 15 is divisible by 3, meaning that x is a multiple of 3. Since you
don’t know anything else about x, it’s entirely possible that x is also divisible by 13, while there are certainly values that
would make x not divisible by 13. Statement (2) is insufficient.

The correct answer is (A).
_________________

"Please hit :thumbup: +1 Kudos if you like this post" :student_man:

_________________
Manish :geek:

"Only I can change my life. No one can do it for me"


Originally posted by CAMANISHPARMAR on 16 Jun 2018, 02:10.
Last edited by CAMANISHPARMAR on 01 Jul 2018, 00:32, edited 1 time in total.
Manager
Manager
avatar
B
Joined: 22 Sep 2017
Posts: 174
CAT Tests
Re: Is x divisible by 39?  [#permalink]

Show Tags

New post 22 Jun 2018, 18:54
Hello CAMANISHPARMAR,

Thank you so much for a beautiful explanation.
Senior Manager
Senior Manager
User avatar
P
Joined: 12 Feb 2015
Posts: 436
Premium Member CAT Tests
Re: Is x divisible by 39?  [#permalink]

Show Tags

New post 24 Jun 2018, 22:20
jackspire wrote:
Hello CAMANISHPARMAR,

Thank you so much for a beautiful explanation.


You are most welcome! Please feel free to get in touch in case if you need any help.

All the very best for your GMAT.
_________________

"Please hit :thumbup: +1 Kudos if you like this post" :student_man:

_________________
Manish :geek:

"Only I can change my life. No one can do it for me"

GMAT Club Bot
Re: Is x divisible by 39? &nbs [#permalink] 24 Jun 2018, 22:20
Display posts from previous: Sort by

Is x divisible by 39?

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

Events & Promotions

PREV
NEXT


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®.