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

 It is currently 12 Dec 2019, 09:46

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

The figure above represents a circular garden, with center O, surround

Author Message
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 59712
The figure above represents a circular garden, with center O, surround  [#permalink]

Show Tags

27 Dec 2015, 10:53
00:00

Difficulty:

5% (low)

Question Stats:

86% (01:08) correct 14% (01:19) wrong based on 43 sessions

HideShow timer Statistics

The figure above represents a circular garden, with center O, surrounded by a circular walkway that is 4 feet wide. What is the area of the walkway, in square feet?

A. 16π
B. 25π
C. 81π
D. 88π
E. 169π

Attachment:

2015-12-27_2152.png [ 37.85 KiB | Viewed 1347 times ]

_________________
Senior Manager
Joined: 28 Feb 2014
Posts: 289
Location: United States
Concentration: Strategy, General Management
Re: The figure above represents a circular garden, with center O, surround  [#permalink]

Show Tags

27 Dec 2015, 22:14
1
Bunuel wrote:

The figure above represents a circular garden, with center O, surrounded by a circular walkway that is 4 feet wide. What is the area of the walkway, in square feet?

A. 16π
B. 25π
C. 81π
D. 88π
E. 169π

Attachment:
2015-12-27_2152.png

13^2 * π =169π

9^2 * π = 81π

169π -81π =88π

D. 88π
EMPOWERgmat Instructor
Status: GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 15704
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Re: The figure above represents a circular garden, with center O, surround  [#permalink]

Show Tags

30 Dec 2015, 11:39
1
Hi All,

This prompt is an example of a 'punch out' question. We'll need to find the total area (of everything), then 'punch out' the area of the part that we DON'T WANT - what's left will be the area of what we DO want.

The big circle has a radius of 13 (the 'inner' radius of 9 + the 4 that represents the width of the walkway). It's area is...

Area = pi(R^2) = pi(13^2) = 169pi

Since we want the area of the walkway, we have to 'punch out' the area of the inner circle. That circle's area is...

Area = pi(R^2) = pi(9^2) = 81pi

Thus, the area of the walkway is.... 169pi - 81pi = 88pi

GMAT assassins aren't born, they're made,
Rich
_________________
Contact Rich at: Rich.C@empowergmat.com

The Course Used By GMAT Club Moderators To Earn 750+

souvik101990 Score: 760 Q50 V42 ★★★★★
ENGRTOMBA2018 Score: 750 Q49 V44 ★★★★★
Non-Human User
Joined: 09 Sep 2013
Posts: 13744
Re: The figure above represents a circular garden, with center O, surround  [#permalink]

Show Tags

13 Nov 2019, 20:28
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.
_________________
Re: The figure above represents a circular garden, with center O, surround   [#permalink] 13 Nov 2019, 20:28
Display posts from previous: Sort by