If x and y are positive integers and y = 9 - x, what is the : GMAT Data Sufficiency (DS)
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 04 Dec 2016, 17:29

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If x and y are positive integers and y = 9 - x, what is the

Author Message
TAGS:

### Hide Tags

Senior Manager
Joined: 28 Aug 2010
Posts: 259
Followers: 6

Kudos [?]: 524 [1] , given: 11

If x and y are positive integers and y = 9 - x, what is the [#permalink]

### Show Tags

27 Dec 2010, 12:49
1
KUDOS
4
This post was
BOOKMARKED
00:00

Difficulty:

75% (hard)

Question Stats:

47% (02:04) correct 53% (00:58) wrong based on 259 sessions

### HideShow timer Statistics

If x and y are positive integers and $$y=\sqrt{9 - x}$$, what is the value of y?

(1) x < 8
(2) y > 1
[Reveal] Spoiler: OA

_________________

Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html
-------------------------------------------------------------------------------------------------
Ajit

Math Expert
Joined: 02 Sep 2009
Posts: 35843
Followers: 6837

Kudos [?]: 89859 [1] , given: 10381

Re: If x and y are positive integers [#permalink]

### Show Tags

27 Dec 2010, 13:08
1
KUDOS
Expert's post
2
This post was
BOOKMARKED
ajit257 wrote:
If x and y are positive integers and y = \sqrt{9 - x} , what is the value of y?
(1) x < 8
(2) y > 1

Given: $$x$$ and $$y$$ are positive integers and $$y=\sqrt{9-x}$$ --> $$y^2=9-x$$ --> $$y^2$$ is a positive perfect square less than 9: so $$y^2=4=2^2$$ if $$x=5$$ or $$y^2=1=1^2$$ if $$x=8$$.

(1) x < 8 --> $$x=5$$ and $$y=2$$. Sufficient.
(2) y > 1 --> $$y=2$$. Sufficient.

_________________
Senior Manager
Joined: 28 Aug 2010
Posts: 259
Followers: 6

Kudos [?]: 524 [0], given: 11

Re: If x and y are positive integers [#permalink]

### Show Tags

27 Dec 2010, 13:15
Hi Bunuel,
why is 2nd statement sufficient. why cant y be root 3 ..it is also greater than 1 or for that matter any integer greater than 1
_________________

Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html
-------------------------------------------------------------------------------------------------
Ajit

Math Expert
Joined: 02 Sep 2009
Posts: 35843
Followers: 6837

Kudos [?]: 89859 [0], given: 10381

Re: If x and y are positive integers [#permalink]

### Show Tags

27 Dec 2010, 13:31
ajit257 wrote:
Hi Bunuel,
why is 2nd statement sufficient. why cant y be root 3 ..it is also greater than 1 or for that matter any integer greater than 1

You should read the stem carefully: "If x and y are positive integers..."

Also $$y^2=9-x$$ --> as given that $$y$$ is a positive integer then $$y^2$$ is a positive perfect square less than 9 (perfect square is a square of an integer): so $$y^2=4=2^2$$ if $$x=5$$ or $$y^2=1=1^2$$ if $$x=8$$.
_________________
Senior Manager
Joined: 08 Nov 2010
Posts: 417
Followers: 7

Kudos [?]: 100 [0], given: 161

Re: If x and y are positive integers [#permalink]

### Show Tags

16 Feb 2011, 12:24
good question. thanks.
_________________
Current Student
Status: Up again.
Joined: 31 Oct 2010
Posts: 541
Concentration: Strategy, Operations
GMAT 1: 710 Q48 V40
GMAT 2: 740 Q49 V42
Followers: 21

Kudos [?]: 397 [0], given: 75

Re: If x and y are positive integers [#permalink]

### Show Tags

16 Feb 2011, 23:57
Testing numbers can be an easy approach here. I solved it in less than 1 min. Answer is D.
_________________

My GMAT debrief: http://gmatclub.com/forum/from-620-to-710-my-gmat-journey-114437.html

Math Expert
Joined: 02 Sep 2009
Posts: 35843
Followers: 6837

Kudos [?]: 89859 [0], given: 10381

Re: If x and y are positive integers and y = 9 - x, what is the [#permalink]

### Show Tags

03 Jul 2013, 00:18
Bumping for review and further discussion*. Get a kudos point for an alternative solution!

*New project from GMAT Club!!! Check HERE

Theory on Algebra: algebra-101576.html

DS Algebra Questions to practice: search.php?search_id=tag&tag_id=29
PS Algebra Questions to practice: search.php?search_id=tag&tag_id=50

Special algebra set: new-algebra-set-149349.html

_________________
Director
Joined: 25 Apr 2012
Posts: 728
Location: India
GPA: 3.21
Followers: 43

Kudos [?]: 666 [1] , given: 723

Re: If x and y are positive integers and y = 9 - x, what is the [#permalink]

### Show Tags

03 Jul 2013, 09:05
1
KUDOS
ajit257 wrote:
If x and y are positive integers and $$y=\sqrt{9 - x}$$, what is the value of y?

(1) x < 8
(2) y > 1

For the given expression we have x,y are positive integers and therefore squaring both sides

y^2= 9-x
From St 1 we have x< 8 -----> so we have possible value of in the range 0<x<8
Only for x=5, we have y=2

So options B,C and E ruled out

St 2 says y>1 so we have y^2=9-x
Now let us say y=2 so x=5
y=3, we get 9=9-x ----> x=0 which is not possible as "x" is a positive integer
hence y=2

Ans should be D

I messed it with choosing A as ans trying to beat the average time and not carefully solving the st2
_________________

“If you can't fly then run, if you can't run then walk, if you can't walk then crawl, but whatever you do you have to keep moving forward.”

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 12867
Followers: 559

Kudos [?]: 157 [0], given: 0

Re: If x and y are positive integers and y = 9 - x, what is the [#permalink]

### Show Tags

21 Apr 2015, 02:30
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: If x and y are positive integers and y = 9 - x, what is the   [#permalink] 21 Apr 2015, 02:30
Similar topics Replies Last post
Similar
Topics:
29 x/y=5.35 If x and y are positive integers, then what is the 14 05 Oct 2010, 18:39
35 If x and y are positive integers such that x = 8y + 12, what 14 17 Sep 2010, 03:23
15 If x and y are positive integers such that x = 8y + 12, what 12 31 Aug 2010, 00:22
10 If x and y are positive integers such that x = 8y +12 . What 9 25 Apr 2010, 06:51
3 If x and y are positive integers and x> y, then what is the value of x 9 11 Jan 2010, 23:10
Display posts from previous: Sort by

# If x and y are positive integers and y = 9 - x, what is the

 Powered by phpBB © phpBB Group and phpBB SEO 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®.