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

It is currently 19 Jun 2019, 00:23

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

For a positive integer n, when 12n is divided by 15, which of the foll

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

Hide Tags

 
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 7468
GMAT 1: 760 Q51 V42
GPA: 3.82
For a positive integer n, when 12n is divided by 15, which of the foll  [#permalink]

Show Tags

New post 11 May 2017, 01:27
1
9
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

81% (01:21) correct 19% (01:20) wrong based on 98 sessions

HideShow timer Statistics

For a positive integer n, when 12n is divided by 15, which of the following cannot be the remainder?

A. 0
B. 3
C. 5
D. 6
E. 9

_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Retired Moderator
User avatar
V
Status: Long way to go!
Joined: 10 Oct 2016
Posts: 1346
Location: Viet Nam
GMAT ToolKit User
Re: For a positive integer n, when 12n is divided by 15, which of the foll  [#permalink]

Show Tags

New post 11 May 2017, 01:35
1
MathRevolution wrote:
For a positive integer n, when 12n is divided by 15, which of the following cannot be the remainder?

A. 0
B. 3
C. 5
D. 6
E. 9


\(\frac{12n}{15}=\frac{15n-3n}{15}=\frac{-3n}{15}\)

Hence, the remainder must be divisible by 3. Hence, 5 cannot be the remainder. The answer is C
_________________
Math Revolution GMAT Instructor
User avatar
V
Joined: 16 Aug 2015
Posts: 7468
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: For a positive integer n, when 12n is divided by 15, which of the foll  [#permalink]

Show Tags

New post 14 May 2017, 18:33
==>From 12n=15Q+r, 12 and 15 are the multiples of 3, so remainder=r must also be the multiple of 3. Therefore, 5 cannot be the remainder.

The answer is C.
Answer: C
_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only $149 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Target Test Prep Representative
User avatar
D
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 6567
Location: United States (CA)
Re: For a positive integer n, when 12n is divided by 15, which of the foll  [#permalink]

Show Tags

New post 20 Dec 2017, 12:30
1
MathRevolution wrote:
For a positive integer n, when 12n is divided by 15, which of the following cannot be the remainder?

A. 0
B. 3
C. 5
D. 6
E. 9


When n = 1, 12(1) = 12 and 12/15 has a remainder of 12.

When n = 2, 12(2) = 24 and 24/15 has a remainder of 9.

When n = 3, 12(3) = 36 and 36/15 has a remainder of 6.

When n = 4, 12(4) = 48 and 48/15 has a remainder of 3.

When n = 5, 12(5) = 60 and 60/15 has a remainder of 0.

If we look at the given answer choices, we see that possible remainders of 12n/15 include 0, 3, 6, and 9, but don’t include 5, so 5 cannot be the remainder when 12n is divided by 15.

Answer: C
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

VP
VP
avatar
P
Joined: 07 Dec 2014
Posts: 1196
Re: For a positive integer n, when 12n is divided by 15, which of the foll  [#permalink]

Show Tags

New post 05 Feb 2019, 21:23
MathRevolution wrote:
For a positive integer n, when 12n is divided by 15, which of the following cannot be the remainder?

A. 0
B. 3
C. 5
D. 6
E. 9


for a divisor 15 to leave a remainder of 5,
the dividend must have a units digit of 5 or 0
multiples of 12 do not have units digits of 5,
and any multiple of 12 ending in 0 is also
a multiple of 15, leaving a remainder of 0
C
GMAT Club Bot
Re: For a positive integer n, when 12n is divided by 15, which of the foll   [#permalink] 05 Feb 2019, 21:23
Display posts from previous: Sort by

For a positive integer n, when 12n is divided by 15, which of the foll

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


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