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

 It is currently 24 Sep 2018, 08:50

### 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

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

# If x and y are positive integers, is x^m+y a multiple of 9?

Author Message
TAGS:

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 6239
GMAT 1: 760 Q51 V42
GPA: 3.82
If x and y are positive integers, is x^m+y a multiple of 9?  [#permalink]

### Show Tags

Updated on: 13 Feb 2017, 02:26
00:00

Difficulty:

55% (hard)

Question Stats:

50% (01:38) correct 50% (01:00) wrong based on 42 sessions

### HideShow timer Statistics

If x and y are positive integers, is$$x^m+y$$ a multiple of 9?

1) m is a multiple of 3
2) x+y is a multiple of 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 $99 for 3 month Online Course" "Free Resources-30 day online access & Diagnostic Test" "Unlimited Access to over 120 free video lessons - try it yourself" Originally posted by MathRevolution on 10 Feb 2017, 03:04. Last edited by Bunuel on 13 Feb 2017, 02:26, edited 1 time in total. Edited the OA. CEO Joined: 12 Sep 2015 Posts: 2892 Location: Canada Re: If x and y are positive integers, is x^m+y a multiple of 9? [#permalink] ### Show Tags 10 Feb 2017, 09:29 Top Contributor MathRevolution wrote: If x and y are positive integers, is $$x^m + y$$ a multiple of 9? 1) m is a multiple of 3 2) x+y is a multiple of 9 Are you sure the correct answer is B? Or perhaps you transcribed the question incorrectly? I ask because.... Target question: Is x^m + y a multiple of 9? Statement 2: x+y is a multiple of 9 There are several values of x and y that satisfy statement 1, YET yield conflicting answers to the target question: Case a: x = 2, y = 7 and m = 1. Here, x+y = 2+7 = 9, and 9 is a multiple of 9. In this case x^m + y = 2^1 + 7 = 9, and 9 IS a multiple of 9 Case b: x = 2, y = 7 and m = 2. Here, x+y = 2+7 = 9, and 9 is a multiple of 9. In this case x^m + y = 2^2 + 7 = 11, and 119 is NOT a multiple of 9 Since we cannot answer the target question with certainty, statement 2 is NOT SUFFICIENT Or perhaps I'm missing something. Cheers, Brent _________________ Brent Hanneson – GMATPrepNow.com Sign up for our free Question of the Day emails Math Revolution GMAT Instructor Joined: 16 Aug 2015 Posts: 6239 GMAT 1: 760 Q51 V42 GPA: 3.82 Re: If x and y are positive integers, is x^m+y a multiple of 9? [#permalink] ### Show Tags 12 Feb 2017, 18:23 ==> In the original condition, there are 3 variables (x, y, m) and in order to match the number of variables to the number of equations, there must be 3 equations. Since there is 1 for con 1) and 1 for con 2), E is most likely to be the answer. By solving con 1) and con 2), (x,y,m)=(1,8,3) yes, but (x,y,m)=(2,7,3) no, hence it is not sufficient. Therefore, the answer is E. Answer: E _________________ 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$99 for 3 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"

Manager
Joined: 29 Oct 2016
Posts: 242
Concentration: Finance, Economics
GMAT 1: 620 Q50 V24
GRE 1: Q167 V147
Re: If x and y are positive integers, is x^m+y a multiple of 9?  [#permalink]

### Show Tags

12 Feb 2017, 19:58
MathRevolution wrote:
==> In the original condition, there are 3 variables (x, y, m) and in order to match the number of variables to the number of equations, there must be 3 equations. Since there is 1 for con 1) and 1 for con 2), E is most likely to be the answer. By solving con 1) and con 2), (x,y,m)=(1,8,3) yes, but (x,y,m)=(2,7,3) no, hence it is not sufficient.

Thanks
Re: If x and y are positive integers, is x^m+y a multiple of 9? &nbs [#permalink] 12 Feb 2017, 19:58
Display posts from previous: Sort by

# If x and y are positive integers, is x^m+y a multiple of 9?

## Events & Promotions

 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®.