It is currently 22 Oct 2017, 19:58

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

The number X is 200% of Y. The number Z increased by 200% is

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

Hide Tags

Intern
Intern
avatar
Joined: 06 Sep 2012
Posts: 42

Kudos [?]: 49 [0], given: 42

Concentration: Social Entrepreneurship
The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 30 Oct 2012, 15:10
5
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  65% (hard)

Question Stats:

53% (01:11) correct 47% (01:11) wrong based on 216 sessions

HideShow timer Statistics

The number X is 200% of Y. The number Z increased by 200% is 50% of X. What percentage of Z is Y?

A. 33.3%
B. 100%
C. 200%
D. 300%
E. 333%

I'm confused on when to use algebra to solve this and when to substitute..
[Reveal] Spoiler: OA

Last edited by Bunuel on 30 Oct 2012, 21:24, edited 1 time in total.
Renamed the topic, edited the question and moved to PS forum.

Kudos [?]: 49 [0], given: 42

2 KUDOS received
Director
Director
User avatar
Status: Done with formalities.. and back..
Joined: 15 Sep 2012
Posts: 636

Kudos [?]: 653 [2], given: 23

Location: India
Concentration: Strategy, General Management
Schools: Olin - Wash U - Class of 2015
WE: Information Technology (Computer Software)
GMAT ToolKit User Premium Member Reviews Badge
Re: GMAT Question- Arithmetic [#permalink]

Show Tags

New post 30 Oct 2012, 20:16
2
This post received
KUDOS
2
This post was
BOOKMARKED
JJ2014 wrote:
The number X is 200% of Y. The number Z increased by 200% is 50% of X. What percentage of Z is Y?
a) 33.3%
b) 100%
c) 200%
d) 300%
e) 333%

I'm confused on when to use algebra to solve this and when to substitute..

Both approaches are fine. Just use whichever u r comfortable with.

Alegbra:

from question:
X =2Y and
3Z = 0.5X
Therefore, 3Z = Y
=> Y is 300% of Z

Ans D.

Picking Numbers:
Start with Z as question asks in terms of Z.
Let Z =100, thus, X=600 and Y=300 from question stems.
Hence Y is 300% of Z.

Ans D.

Hope it helps.
_________________

Lets Kudos!!! ;-)
Black Friday Debrief

Kudos [?]: 653 [2], given: 23

Intern
Intern
User avatar
Joined: 02 Sep 2011
Posts: 17

Kudos [?]: [0], given: 42

Schools: Goizueta '16
GPA: 3.94
Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 08 Dec 2013, 04:30
Dear Vips0000,

The problem states that "The number Z increased by 200% is 50% of X", doesn't this mean that 2Z=0.5X ?

Thanks in Advance.

Papua

Kudos [?]: [0], given: 42

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 41912

Kudos [?]: 129370 [1], given: 12197

Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 08 Dec 2013, 07:15
1
This post received
KUDOS
Expert's post

Kudos [?]: 129370 [1], given: 12197

Intern
Intern
User avatar
Joined: 02 Sep 2011
Posts: 17

Kudos [?]: [0], given: 42

Schools: Goizueta '16
GPA: 3.94
Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 09 Dec 2013, 12:14
Thank you Bunuel for explanation :)

Kudos [?]: [0], given: 42

Manager
Manager
avatar
Joined: 01 Feb 2012
Posts: 86

Kudos [?]: 41 [0], given: 151

Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 01 Feb 2015, 13:46
Vips0000 wrote:
JJ2014 wrote:
The number X is 200% of Y. The number Z increased by 200% is 50% of X. What percentage of Z is Y?
a) 33.3%
b) 100%
c) 200%
d) 300%
e) 333%

I'm confused on when to use algebra to solve this and when to substitute..

Both approaches are fine. Just use whichever u r comfortable with.

Alegbra:

from question:
X =2Y and
3Z = 0.5X
Therefore, 3Z = Y
=> Y is 300% of Z

Ans D.

Hope it helps.


Hi Bunuel,

As you mentioned in an above post that Z increased by 200% is Z + 200/100*Z = 3Z.
So by the same logic in this question -

if 3Z = Y then does it not mean that Y is 200% of Z? so the answer would be C in that case?

can you please help! Thanks.

Kudos [?]: 41 [0], given: 151

Expert Post
1 KUDOS received
EMPOWERgmat Instructor
User avatar
P
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 9990

Kudos [?]: 3416 [1], given: 172

Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 01 Feb 2015, 15:38
1
This post received
KUDOS
Expert's post
Hi All,

This question can be solved by TESTing VALUES. We have to pay very careful attention to the exact wording used (there's a difference between "200% of....." and "increased by 200%...").

First, we're told that X is 200% of Y.

IF....
Y = 100
X = 200

Next, we're told that if Z is INCREASED BY 200%, then Z is 50% of X.

Z + 2Z = (1/2)(X)
3Z = (1/2)(200)
3Z = 100
Z = 100/3

We're asked what percent of Z is Y.....

Y/Z = 100 / (100/3) = 3.0 = 300%

Final Answer:
[Reveal] Spoiler:
D


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

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

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

Kudos [?]: 3416 [1], given: 172

Manager
Manager
avatar
Joined: 01 Feb 2012
Posts: 86

Kudos [?]: 41 [0], given: 151

Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 02 Feb 2015, 12:36
Thanks a ton Rich, that was really helpful...difference between 200% of...and increased by 200% was crucial here...

EMPOWERgmatRichC wrote:
Hi All,

This question can be solved by TESTing VALUES. We have to pay very careful attention to the exact wording used (there's a difference between "200% of....." and "increased by 200%...").

First, we're told that X is 200% of Y.

IF....
Y = 100
X = 200

Next, we're told that if Z is INCREASED BY 200%, then Z is 50% of X.

Z + 2Z = (1/2)(X)
3Z = (1/2)(200)
3Z = 100
Z = 100/3

We're asked what percent of Z is Y.....

Y/Z = 100 / (100/3) = 3.0 = 300%

Final Answer:
[Reveal] Spoiler:
D


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

Kudos [?]: 41 [0], given: 151

Expert Post
1 KUDOS received
EMPOWERgmat Instructor
User avatar
P
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 9990

Kudos [?]: 3416 [1], given: 172

Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 02 Feb 2015, 12:57
1
This post received
KUDOS
Expert's post
Hi fireinbelly,

The GMAT will test you on these differences at least once, so they're important to note.

Here's a pattern that might help you in future questions:

Raising a value by 100% means that you DOUBLE the value

eg
X = 15
raising 15 by 100% of 15 = 15 + 15 = 30
So a 100% increase is the same a multiplying that value by 2

Raising a value by 200% means that you TRIPLE the value

Raising a value by 300% means that you QUADRUPLE the value

Etc.

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

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

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

Kudos [?]: 3416 [1], given: 172

Intern
Intern
avatar
Joined: 14 Aug 2013
Posts: 24

Kudos [?]: 6 [0], given: 11

Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 06 Feb 2015, 03:36
Let Y = 100 . X is 200% Y . This means X = 200.

If Z is increased by 200 % then this will be 50% X

50% X = 100 .

If the value of Z is increased by 3 times then resulting number = 100

Therefore Z = 33.33

Now we have to identify 100 is what % of 33.33 .

Answer : 300%

Kudos [?]: 6 [0], given: 11

Expert Post
EMPOWERgmat Instructor
User avatar
P
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 9990

Kudos [?]: 3416 [0], given: 172

Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: 340 Q170 V170
Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 23 Mar 2016, 11:18
Hi briangeorgewebb,

Did you have a question about this prompt (or the approach that I took to solve it?)?

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

760+: Learn What GMAT Assassins Do to Score at the Highest Levels
Contact Rich at: Rich.C@empowergmat.com

Rich Cohen

Co-Founder & GMAT Assassin

Special Offer: Save $75 + GMAT Club Tests Free
  Official GMAT Exam Packs + 70 Pt. Improvement Guarantee
www.empowergmat.com/

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

Kudos [?]: 3416 [0], given: 172

CEO
CEO
User avatar
G
Joined: 17 Jul 2014
Posts: 2605

Kudos [?]: 398 [0], given: 184

Location: United States (IL)
Concentration: Finance, Economics
GMAT 1: 650 Q49 V30
GPA: 3.92
WE: General Management (Transportation)
GMAT ToolKit User Premium Member Reviews Badge CAT Tests
Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 09 May 2016, 19:10
JJ2014 wrote:
The number X is 200% of Y. The number Z increased by 200% is 50% of X. What percentage of Z is Y?

A. 33.3%
B. 100%
C. 200%
D. 300%
E. 333%

I'm confused on when to use algebra to solve this and when to substitute..


x=2y
the confusion is when we have Z increased by 200%
that means Z + 200% of z, which is 2z
so we have 3z=0.5x
multiply by 2
6z=x
6z=2y
3z=y
y is 300% of z.

Kudos [?]: 398 [0], given: 184

GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 09 Sep 2013
Posts: 16552

Kudos [?]: 274 [0], given: 0

Premium Member
Re: The number X is 200% of Y. The number Z increased by 200% is [#permalink]

Show Tags

New post 20 Aug 2017, 13:20
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.
_________________

GMAT Books | GMAT Club Tests | Best Prices on GMAT Courses | GMAT Mobile App | Math Resources | Verbal Resources

Kudos [?]: 274 [0], given: 0

Re: The number X is 200% of Y. The number Z increased by 200% is   [#permalink] 20 Aug 2017, 13:20
Display posts from previous: Sort by

The number X is 200% of Y. The number Z increased by 200% is

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


GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.