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

It is currently 18 Aug 2018, 21:14

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

If x is a positive integer, is (x+y) even?

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

Hide Tags

Intern
Intern
User avatar
Joined: 18 Jun 2012
Posts: 37
GMAT Date: 09-17-2012
If x is a positive integer, is (x+y) even?  [#permalink]

Show Tags

New post Updated on: 20 Nov 2016, 08:07
6
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

66% (00:58) correct 34% (01:16) wrong based on 191 sessions

HideShow timer Statistics

If x is a positive integer, is (x+y) even?

(1) K^x*K^y =1
(2) K is not equal to 1

Originally posted by ananthpatri on 05 Aug 2012, 23:02.
Last edited by stonecold on 20 Nov 2016, 08:07, edited 2 times in total.
Edited the question.
Director
Director
User avatar
Joined: 22 Mar 2011
Posts: 604
WE: Science (Education)
Re: If x is a positive integer, is (x+y) even?  [#permalink]

Show Tags

New post 06 Aug 2012, 00:54
ananthpatri wrote:
If x is a positive integer, is (x+y) even?

(1) K^x*K^y =1
(2) K is not equal to 1


(1) States \(K^{x+y}=1\). If \(K = 1, x + y\) can be odd or even. Not sufficient.

(2) Nothing about \(x + y\). Not sufficient.

(1) and (2) together: Sufficient, because necessarily \(x + y = 0\).

Answer C.
_________________

PhD in Applied Mathematics
Love GMAT Quant questions and running.

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 47983
Re: If x is a positive integer, is (x+y) even?  [#permalink]

Show Tags

New post 06 Aug 2012, 01:03
2
EvaJager wrote:
ananthpatri wrote:
If x is a positive integer, is (x+y) even?

(1) K^x*K^y =1
(2) K is not equal to 1


(1) States \(K^{x+y}=1\). If \(K = 1, x + y\) can be odd or even. Not sufficient.

(2) Nothing about \(x + y\). Not sufficient.

(1) and (2) together: Sufficient, because necessarily \(x + y = 0\).

Answer C.


x+y is not necessarily zero. If k=-1, then x+y can be ANY even number.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Director
Director
User avatar
Joined: 22 Mar 2011
Posts: 604
WE: Science (Education)
Re: If x is a positive integer, is (x+y) even?  [#permalink]

Show Tags

New post 06 Aug 2012, 01:08
1
Bunuel wrote:
EvaJager wrote:
ananthpatri wrote:
If x is a positive integer, is (x+y) even?

(1) K^x*K^y =1
(2) K is not equal to 1


(1) States \(K^{x+y}=1\). If \(K = 1, x + y\) can be odd or even. Not sufficient.

(2) Nothing about \(x + y\). Not sufficient.

(1) and (2) together: Sufficient, because necessarily \(x + y = 0\).

Answer C.


x+y is not necessarily zero. If k=-1, then x+y can be ANY even number.


You are absolutely right. Nothing stated about K! At least the answer is still C.
_________________

PhD in Applied Mathematics
Love GMAT Quant questions and running.

Intern
Intern
User avatar
Joined: 18 Jun 2012
Posts: 37
GMAT Date: 09-17-2012
Re: If x is a positive integer, is (x+y) even?  [#permalink]

Show Tags

New post 06 Aug 2012, 01:09
Thanks for the answer.
Retired Moderator
User avatar
B
Joined: 05 Jul 2006
Posts: 1731
GMAT ToolKit User Premium Member
Re: If x is a positive integer, is (x+y) even?  [#permalink]

Show Tags

New post 29 Oct 2016, 11:00
ananthpatri wrote:
If x is a positive integer, is (x+y) even?

(1) K^x*K^y =1
(2) K is not equal to 1



FROM STEM , X IS +VE but x+y doesnt have to be +ve , is x+y even??

from 1

k = 1 and x+y = anything or k= -1 , x+y = even or k is anything and x+y = 0 ... insuff

from 2

k is not 1 ... insuff

both together

k can = 1 and (x+y = even ) or k = anything and (x+y = 0) .... in either case x+y is even ... suff

C
BSchool Forum Moderator
User avatar
D
Joined: 12 Aug 2015
Posts: 2649
GRE 1: Q169 V154
GMAT ToolKit User Premium Member
Re: If x is a positive integer, is (x+y) even?  [#permalink]

Show Tags

New post 20 Nov 2016, 08:12
Okay
so we need to get if x+y is even or not
x=> integer
remember => y is not specified as to being an integer.
Lets ook at statements

Statement 1
k^x*k^y=> k^(x+y)=> 1
okay if k is one then x+y can be anything => even/odd/fraction etc
hence not sufficient.
Statement 2
k≠1
no clue of x and y hence not sufficient
Lets Combine the statements
Hmm
K≠1
if k=-1 => x+y must be even as (-1)^even =1 and (-1)odd = -1
if k is any other integer except 1 and -1 then x+y must be zero.
But hey, zero is an even too.
BINGO
x+y must be always either 0 or even
Hence C
_________________


MBA Financing:- INDIAN PUBLIC BANKS vs PRODIGY FINANCE!

Getting into HOLLYWOOD with an MBA!

The MOST AFFORDABLE MBA programs!

STONECOLD's BRUTAL Mock Tests for GMAT-Quant(700+)

AVERAGE GRE Scores At The Top Business Schools!

Senior Manager
Senior Manager
User avatar
G
Joined: 14 Dec 2017
Posts: 453
Re: If x is a positive integer, is (x+y) even?  [#permalink]

Show Tags

New post 12 Jul 2018, 04:41
ananthpatri wrote:
If x is a positive integer, is (x+y) even?

(1) K^x*K^y =1
(2) K is not equal to 1



Statement 1: K^x*K^y =1

K^(x+y) = 1, therefore

K = 1, then x+y can odd/even
K > 1, then x+y = 0, hence even
K = -1, then x+y is even
K < -1, then x+y = 0 hence even

Statement 1 is not sufficient.



Statement 2: K is not equal to 1.

No information about x or y. Statement 2 is not sufficient.


Combining, we get K = -1, > 1 or < -1, hence x+y is even

Combining is sufficient.


Answer C.


Thanks,
GyM
Re: If x is a positive integer, is (x+y) even? &nbs [#permalink] 12 Jul 2018, 04:41
Display posts from previous: Sort by

If x is a positive integer, is (x+y) even?

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

Events & Promotions

PREV
NEXT


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®.