If x and y are integers, is x + y even?
(1) x + 2y is odd.
(2) xy is odd.
OA B
Source: GMAT Prep
If x and y are integers, is x + y even? (1) x + 2y is odd.
This topic has expert replies
-
- Moderator
- Posts: 7187
- Joined: Thu Sep 07, 2017 4:43 pm
- Followed by:23 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
GMAT/MBA Expert
- Jay@ManhattanReview
- GMAT Instructor
- Posts: 3008
- Joined: Mon Aug 22, 2016 6:19 am
- Location: Grand Central / New York
- Thanked: 470 times
- Followed by:34 members
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
(x + y) even is even if any one of the two conditions are met: 1. Both x and y are odd, or 2. Both x and y are even.BTGmoderatorDC wrote:If x and y are integers, is x + y even?
(1) x + 2y is odd.
(2) xy is odd.
OA B
Source: GMAT Prep
Let's take each statement one by one.
(1) x + 2y is odd.
1. Since 2y is odd irrespective of whether y is even and odd, we can't get wether y is even or odd. (x + 2y) is odd shows that x is odd. Since we do not know whether y is even or odd, we can't get the answer. Insufficient.
(2) xy is odd.
=> x as well as y is odd. Thus, (x + y) = even. Sufficient.
The correct answer: B
Hope this helps!
-Jay
_________________
Manhattan Review GMAT Prep
Locations: GMAT Classes Manchester | GMAT Prep Courses Beijing | LSAT Prep Courses Los Angeles | SAT Prep Classes Manhattan | and many more...
Schedule your free consultation with an experienced GMAT Prep Advisor! Click here.
GMAT/MBA Expert
- Ian Stewart
- GMAT Instructor
- Posts: 2621
- Joined: Mon Jun 02, 2008 3:17 am
- Location: Montreal
- Thanked: 1090 times
- Followed by:355 members
- GMAT Score:780
Timer
00:00
Your Answer
A
B
C
D
E
Global Stats
In case this is confusing for anyone reading, I'm sure this is meant to say "Since 2y is even irrespective of whether y is even or odd".Jay@ManhattanReview wrote: (1) x + 2y is odd.
1. Since 2y is odd irrespective of whether y is even and odd
For online GMAT math tutoring, or to buy my higher-level Quant books and problem sets, contact me at ianstewartgmat at gmail.com
ianstewartgmat.com
ianstewartgmat.com