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

 It is currently 15 Oct 2019, 03:03

### 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

# 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

Math Expert
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

24 Mar 2019, 21:56
00:00

Difficulty:

(N/A)

Question Stats:

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

### HideShow timer Statistics

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

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

### Show Tags

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
Joined: 12 Sep 2015
Posts: 4000
Re: A positive number x has the property that x% of x is 4. What is x?  [#permalink]

### Show Tags

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

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!

Cheers,
Brent
_________________
Test confidently with gmatprepnow.com
Target Test Prep Representative
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

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

_________________

# Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
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.

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