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

It is currently 21 Sep 2018, 03:18

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

If the radius of a circle is increased by 6%, then the area of the cir

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

Hide Tags

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49298
If the radius of a circle is increased by 6%, then the area of the cir  [#permalink]

Show Tags

New post 29 Oct 2017, 01:17
00:00
A
B
C
D
E

Difficulty:

  15% (low)

Question Stats:

83% (00:57) correct 17% (00:52) wrong based on 63 sessions

HideShow timer Statistics

Board of Directors
User avatar
P
Status: QA & VA Forum Moderator
Joined: 11 Jun 2011
Posts: 4032
Location: India
GPA: 3.5
WE: Business Development (Commercial Banking)
GMAT ToolKit User Premium Member
Re: If the radius of a circle is increased by 6%, then the area of the cir  [#permalink]

Show Tags

New post 29 Oct 2017, 08:44
Bunuel wrote:
If the radius of a circle is increased by 6%, then the area of the circle is increased by

(A) .36%
(B) 3.6%
(C) 6%
(D) 12.36%
(E) 36%

Area of the Circle = \(πr^2\)

So, Percentage change in area of the Circle is 6 + 6 +6*6/100 = 12.36%

Thus, correct answer will be (D) 12.36%
_________________

Thanks and Regards

Abhishek....

PLEASE FOLLOW THE RULES FOR POSTING IN QA AND VA FORUM AND USE SEARCH FUNCTION BEFORE POSTING NEW QUESTIONS

How to use Search Function in GMAT Club | Rules for Posting in QA forum | Writing Mathematical Formulas |Rules for Posting in VA forum | Request Expert's Reply ( VA Forum Only )

Senior SC Moderator
avatar
V
Joined: 22 May 2016
Posts: 1978
Premium Member CAT Tests
If the radius of a circle is increased by 6%, then the area of the cir  [#permalink]

Show Tags

New post 29 Oct 2017, 21:11
Bunuel wrote:
If the radius of a circle is increased by 6%, then the area of the circle is increased by

(A) .36%
(B) 3.6%
(C) 6%
(D) 12.36%
(E) 36%

Increase in area =
((scale factor)\(^2\) - 1) * 100

6 percent increase = 1.06 scale factor

(1.06)\(^2\) = 1.1236
(1.1236 - 1) * 100 =
(.1236 * 100) = 12.36 percent

Answer D
_________________

In the depths of winter, I finally learned
that within me there lay an invincible summer.

-- Albert Camus, "Return to Tipasa"

Manager
Manager
User avatar
G
Joined: 07 Jun 2017
Posts: 175
Location: India
Concentration: Technology, General Management
GMAT 1: 660 Q46 V38
GPA: 3.6
WE: Information Technology (Computer Software)
GMAT ToolKit User Reviews Badge
Re: If the radius of a circle is increased by 6%, then the area of the cir  [#permalink]

Show Tags

New post 29 Oct 2017, 22:24
area of the circle is pi*r^2
so percentage increase equal to (1.06)^2 = 12.36 %
_________________

Regards,
Naveen
email: nkmungila@gmail.com
Please press kudos if you like this post

Target Test Prep Representative
User avatar
G
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 3516
Location: United States (CA)
Re: If the radius of a circle is increased by 6%, then the area of the cir  [#permalink]

Show Tags

New post 31 Oct 2017, 16:15
Bunuel wrote:
If the radius of a circle is increased by 6%, then the area of the circle is increased by

(A) .36%
(B) 3.6%
(C) 6%
(D) 12.36%
(E) 36%


We can let the original area = πr^2; thus, the new area is π(1.06r)^2 = π(1.1236)r^2.

We use the percent increase formula: (New - Old)/Old x 100. Thus, the area is increased by:

[π(1.1236)r^2 - πr^2]/πr^2 x 100

[0.01236πr^2/]/πr^2 x 100 = 12.36%

Answer: D
_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Re: If the radius of a circle is increased by 6%, then the area of the cir &nbs [#permalink] 31 Oct 2017, 16:15
Display posts from previous: Sort by

If the radius of a circle is increased by 6%, then the area of the cir

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

Events & Promotions

PREV
NEXT


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