If x + 2y = z, what is the value of x? : GMAT Data Sufficiency (DS)
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 23 Jan 2017, 15:26

### 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

# Events & Promotions

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

# If x + 2y = z, what is the value of x?

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

### Hide Tags

Manager
Joined: 11 Aug 2009
Posts: 126
Followers: 1

Kudos [?]: 125 [0], given: 3

If x + 2y = z, what is the value of x? [#permalink]

### Show Tags

19 Nov 2009, 06:10
00:00

Difficulty:

25% (medium)

Question Stats:

69% (01:51) correct 31% (00:50) wrong based on 284 sessions

### HideShow timer Statistics

If x + 2y = z, what is the value of x?

(1) 3y = 4.5 + 1.5z

(2) y = 2
[Reveal] Spoiler: OA

Last edited by Bunuel on 17 Mar 2015, 06:28, edited 1 time in total.
Renamed the topic, edited the question and added the OA.
Senior Manager
Joined: 30 Aug 2009
Posts: 286
Location: India
Concentration: General Management
Followers: 3

Kudos [?]: 163 [0], given: 5

Re: If x + 2y = z, what is the value of x? [#permalink]

### Show Tags

19 Nov 2009, 07:24
kairoshan wrote:
If x + 2y = z, what is the value of x?

(1) 3y = 4.5 + 1.5z

(2) y = 2

A

1.equating this in x+2y =z we can find the value of x.suff
2. we do not know value of z hence insuff
SVP
Joined: 17 Jul 2014
Posts: 2216
Location: United States (IL)
Concentration: Finance, Economics
Schools: Stanford '19 (S)
GMAT 1: 560 Q42 V26
GMAT 2: 550 Q39 V27
GMAT 3: 560 Q43 V24
GMAT 4: 650 Q49 V30
GPA: 3.92
WE: General Management (Transportation)
Followers: 20

Kudos [?]: 272 [0], given: 140

Re: If x + 2y = z, what is the value of x? [#permalink]

### Show Tags

17 Mar 2015, 05:16
with 1, we get this equation:
y=1.5+0.5z
rearranging the first equation, we get: x+3+z=z
cancel Z's: z+3 = 0 -> x=-3
2. we still have Z for which we have no information.

answ. A
Math Expert
Joined: 02 Sep 2009
Posts: 36618
Followers: 7101

Kudos [?]: 93565 [0], given: 10578

Re: If x + 2y = z, what is the value of x? [#permalink]

### Show Tags

17 Mar 2015, 06:46
Expert's post
1
This post was
BOOKMARKED
kairoshan wrote:
If x + 2y = z, what is the value of x?

(1) 3y = 4.5 + 1.5z

(2) y = 2

This is an example of a C-Trap question. For more check HERE.
_________________
Manager
Joined: 17 Mar 2014
Posts: 238
Location: India
Concentration: Operations, Strategy
GMAT 1: 670 Q48 V35
GPA: 3.19
WE: Information Technology (Computer Software)
Followers: 4

Kudos [?]: 68 [0], given: 175

Re: If x + 2y = z, what is the value of x? [#permalink]

### Show Tags

17 Mar 2015, 08:34
If you try to solve this question without using pen then mostly you will get wrong answer as the equations are written to manipulate.
Simplify equations , using only statement 1 , you will get answer as x=-3.
Hence , statement 1 is enough.
_________________

Press +1 Kudos if you find this Post helpful

EMPOWERgmat Instructor
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 8336
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Followers: 382

Kudos [?]: 2472 [0], given: 163

Re: If x + 2y = z, what is the value of x? [#permalink]

### Show Tags

18 Mar 2015, 18:54
HI All,

This DS question is based on the idea of spotting a common 'multiple' among variables (and it's a concept that you'll likely see at least once on Test Day).

If you don't spot the multiple though, you can still get to the correct answer. While the work will take a little more effort, you can TEST VALUES and prove that a pattern exists.

We're told that X + 2Y = Z. We're asked for the value of X.

Fact 1: 3Y = 4.5 + 1.5Z

IF.....
Z = 0
3Y = 4.5
Y = 1.5

X + 2(1.5) = 0
X + 3 = 0
X = -3
The answer to the question is -3

IF...
Z = 2
3Y = 7.5
Y = 2.5

X + 2(2.5) = 2
X + 5 = 2
X = -3
The answer to the question is -3

IF....
Z = -3
3Y = 0
Y = 0

X + 2(0) = -3
X = -3
The answer to the question is -3

This is clearly a pattern. X is ALWAYS equal to -3
Fact 1 is SUFFICIENT

Fact 2: Y = 2

With this information, the original equation becomes....
X + 2(3) = Z
X + 6 = Z

Without the value of Z, we cannot figure out the value of X.
Fact 2 is INSUFFICIENT

Final Answer:
[Reveal] Spoiler:
B

GMAT assassins aren't born, they're made,
Rich
_________________

# Rich Cohen

Co-Founder & GMAT Assassin

# Special Offer: Save \$75 + GMAT Club Tests

60-point improvement guarantee
www.empowergmat.com/

***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************

Senior Manager
Status: Exam scheduled!!
Joined: 05 Sep 2016
Posts: 411
Location: United States (WI)
Concentration: Marketing, Technology
WE: Other (Law)
Followers: 3

Kudos [?]: 13 [0], given: 246

If x + 2y = z, what is the value of x? [#permalink]

### Show Tags

18 Sep 2016, 17:06
Correct answer is A. Here's why:

(1) 3y = 9/2 + (3/2)z --> Multiply by 2

6y = 9 + 3z

Plug in main equation & you get...6y = 9 + 3(x+2y)

This simplifies down to 3x = -9 --> x = -3

SUFFICIENT

(2) y = 2

INSUFFICIENT - we cannot get the value of x with just the value of y alone; we need z as well (or some relationship between y and z)
If x + 2y = z, what is the value of x?   [#permalink] 18 Sep 2016, 17:06
Similar topics Replies Last post
Similar
Topics:
If x^(1/2) = y, what is the value of x? 3 25 Mar 2016, 02:42
What is the value of y? (1) 2 x + 2 y = 14 (2) 2 y + 2 z = 14 3 21 Mar 2016, 06:17
1 If 2x = 2y – 3z, what is the value of z? 6 14 Apr 2015, 03:52
44 |x|=|2y|, what is the value of x-2y? 20 27 May 2012, 07:18
2 If x^2 y = w, what is the value of x? 6 05 Jan 2010, 11:33
Display posts from previous: Sort by

# If x + 2y = z, what is the value of x?

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

 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®.