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

It is currently 15 Oct 2019, 03:03

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

A positive number x has the property that x% of x is 4. What is x?

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

Hide Tags

Find Similar Topics 
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 58312
A positive number x has the property that x% of x is 4. What is x?  [#permalink]

Show Tags

New post 24 Mar 2019, 21:56
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

96% (00:38) correct 4% (00:43) wrong based on 25 sessions

HideShow timer Statistics

GMAT Club Legend
GMAT Club Legend
User avatar
D
Joined: 18 Aug 2017
Posts: 4996
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
GMAT ToolKit User Premium Member
Re: A positive number x has the property that x% of x is 4. What is x?  [#permalink]

Show Tags

New post 24 Mar 2019, 22:56
Bunuel wrote:
A positive number x has the property that x% of x is 4. What is x?

(A) 2
(B) 4
(C) 10
(D) 20
(E) 40


given
x/100 * x =4
or say
x^2 = 4*100
x = 2* 10
x= 20
IMO D
GMAT Club Legend
GMAT Club Legend
User avatar
V
Joined: 12 Sep 2015
Posts: 4000
Location: Canada
Re: A positive number x has the property that x% of x is 4. What is x?  [#permalink]

Show Tags

New post 25 Mar 2019, 07:29
Top Contributor
Bunuel wrote:
A positive number x has the property that x% of x is 4. What is x?

(A) 2
(B) 4
(C) 10
(D) 20
(E) 40


APPROACH #1: Algebra
Given: x% of x is 4
Rewrite as: x/100 of x = 4
Rewrite as: (x/100)(x) = 4
Simplify: x²/100 = 4
Multiply both sides by 100 to get: x² = 400
So, EITHER x = 20 OR x = -20

We're told that x is POSITIVE, so x must be 20
Answer: D


APPROACH #2: Test answer choices
A) Does 2% of 2 = 4? No, 2% of 2 will be less than 2
B) Does 4% of 4 = 4? No, 4% of 4 will be less than 4
C) Does 10% of 10 = 4? No, 10% of 10 = 1
D) Does 20% of 20 = 4? YES!

Answer: D

Cheers,
Brent
_________________
Test confidently with gmatprepnow.com
Image
Target Test Prep Representative
User avatar
D
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8043
Location: United States (CA)
Re: A positive number x has the property that x% of x is 4. What is x?  [#permalink]

Show Tags

New post 27 Mar 2019, 19:01
Bunuel wrote:
A positive number x has the property that x% of x is 4. What is x?

(A) 2
(B) 4
(C) 10
(D) 20
(E) 40


Just as we can express 25% as 25/100, we can express x% as x/100. In the phrase “x% of x is 4,” we recall that the word “of” means multiply and “is” means equals. Thus, we can create the equation:

(x/100)(x) = 4

x^2 = 400

x = 20

Answer: D
_________________

Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
TTP - Target Test Prep Logo
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

GMAT Club Bot
Re: A positive number x has the property that x% of x is 4. What is x?   [#permalink] 27 Mar 2019, 19:01
Display posts from previous: Sort by

A positive number x has the property that x% of x is 4. What is x?

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





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne