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

 It is currently 18 Apr 2019, 16:01

### 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

# When x+y is integer, is y an integer?

Author Message
TAGS:

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 7224
GMAT 1: 760 Q51 V42
GPA: 3.82
When x+y is integer, is y an integer?  [#permalink]

### Show Tags

04 Jul 2017, 18:15
00:00

Difficulty:

45% (medium)

Question Stats:

52% (00:46) correct 48% (01:02) wrong based on 56 sessions

### HideShow timer Statistics

When x+y is integer, is y an integer?

1) x is an integer.
2) x+2y is an integer.

_________________
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"
Math Expert
Joined: 02 Aug 2009
Posts: 7556
Re: When x+y is integer, is y an integer?  [#permalink]

### Show Tags

04 Jul 2017, 18:36
MathRevolution wrote:
When x+y is integer, is y an integer?

1) x is an integer.
2) x+2y is an integer.

Hi,

SUM or DIFFERENCE of 2 integers will be integer..

x+y is INTEGER.
Let's see the statements..
1) x is an integer.
Difference (x+y)-(x) = y should be INTEGER..
Sufficient
2) x+2y is integer..
Difference (x+2y)-(x+y)=y should be INTEGER
Sufficient

D
_________________
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 7224
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: When x+y is integer, is y an integer?  [#permalink]

### Show Tags

06 Jul 2017, 01:17
==> In the original condition, there are 2 variables (x,y) and 1 equation (x+y=integer). In order to match the number of variables to the number of equations, there must be 1 more equation. Since there is 1 for con 1) and 1 for con 2), D is most likely to be the answer. For con 1), from x=integer and x+y=integer, integer+y=integer, you get y=integer, which is yes and sufficient. For con 2), from x+2y=x+y+y=integer, integer+y=integer, you get y=integer, which is also yes and sufficient.

_________________
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"
Re: When x+y is integer, is y an integer?   [#permalink] 06 Jul 2017, 01:17
Display posts from previous: Sort by