NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 18:42 It is currently 25 Apr 2024, 18:42
Decision Tracker
My Rewards
New posts
New comers' posts

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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

A pilot surveys a flat circular area represented by 4π square inches

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92915
Own Kudos [?]: 619034 [1]
Given Kudos: 81595
Send PM
CAT Tests Forum Quiz Mode
A pilot surveys a flat circular area represented by 4π square inches [#permalink] New post   16 Nov 2017, 08:27
1
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

25% (medium)

Question Stats:

73% (01:11) correct 28% (01:02) wrong based on 52 sessions
Hide Show timer Statistics
A pilot surveys a flat circular area represented by 4π square inches on a map. If 1 inch on the map represents 60 miles, how many square miles does the pilot survey?

(A) 15π
(B) 240π
(C) 900π
(D) 7,200π
(E) 14,400π
ShowHide Answer
Official Answer
E
User avatar
B
Navski
Intern
Intern
Joined: 27 Jan 2017
Posts: 42
Own Kudos [?]: 15 [0]
Given Kudos: 31
GMAT 1: 570 Q44 V24
GMAT 2: 550 Q36 V29
GMAT 3: 560 Q36 V31
GMAT 4: 640 Q41 V37
GMAT 5: 690 Q48 V36
Send PM
Reviews Badge
Re: A pilot surveys a flat circular area represented by 4π square inches [#permalink] New post   16 Nov 2017, 09:06
Answer is E here.

We know its a circular area represented by 4pi square inches. Area of a circle is Pi*r^2. So R is = 2 inches.

Given the information we know that 1inch = 60 miles so the area of the circle in terms of miles is ((2*60)^2) * pi.

From there it's just some quick math to get to 14,400 pi.
User avatar
L
Abhishek009
Board of Directors
Joined: 11 Jun 2011
Status:QA & VA Forum Moderator
Posts: 6072
Own Kudos [?]: 4689 [0]
Given Kudos: 463
Location: India
GPA: 3.5
WE:Business Development (Commercial Banking)
Send PM
GMAT ToolKit User
Re: A pilot surveys a flat circular area represented by 4π square inches [#permalink] New post   16 Nov 2017, 09:29
Bunuel wrote:
A pilot surveys a flat circular area represented by 4π square inches on a map. If 1 inch on the map represents 60 miles, how many square miles does the pilot survey?

(A) 15π
(B) 240π
(C) 900π
(D) 7,200π
(E) 14,400π

\(πr^2 = 4π\)

So, \(r = 2 inch\)

Actual radius on map = 120 miles, so actual area on land is \(120^2π\) = \(14,400π\) , Answer will be (E)
avatar
S
akshata19
Manager
Manager
Joined: 22 May 2017
Posts: 86
Own Kudos [?]: 104 [0]
Given Kudos: 105
Send PM
Re: A pilot surveys a flat circular area represented by 4π square inches [#permalink] New post   16 Nov 2017, 10:07
Direct calculation
A = 4π sq inch
= 4π * 60 * 60 (since square multiply twice the conversion )
= 14400π

Posted from my mobile device
User avatar
L
generis
Senior SC Moderator
Joined: 22 May 2016
Posts: 5330
Own Kudos [?]: 35490 [0]
Given Kudos: 9464
Send PM
CAT Tests
A pilot surveys a flat circular area represented by 4π square inches [#permalink] New post   16 Nov 2017, 11:54
Expert Reply
Bunuel wrote:
A pilot surveys a flat circular area represented by 4π square inches on a map. If 1 inch on the map represents 60 miles, how many square miles does the pilot survey?

(A) 15π
(B) 240π
(C) 900π
(D) 7,200π
(E) 14,400π

Map area of circular region in square inches =
\(πr^2=4π\), \(r^2=4\), so map \(r=2\) inches

\(\frac{Map}{Actual}=\frac{1inch}{60mi}=\frac{2in}{120mi}\)
Actual radius of the circular area is 120 miles.

Actual area in square miles =
\(πr^2=(120)^2π=14,400π\)

Answer E
User avatar
L
ScottTargetTestPrep
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18761
Own Kudos [?]: 22054 [0]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: A pilot surveys a flat circular area represented by 4π square inches [#permalink] New post   17 Nov 2017, 14:27
Expert Reply
Bunuel wrote:
A pilot surveys a flat circular area represented by 4π square inches on a map. If 1 inch on the map represents 60 miles, how many square miles does the pilot survey?

(A) 15π
(B) 240π
(C) 900π
(D) 7,200π
(E) 14,400π


Since 1 inch = 60 miles, 1 square inch = 60 x 60 = 3,600 square miles.

Thus, 4π square inches = 4π x 3,600 = 14,400π square miles.

Alternate Solution:

We can create a proportion to solve this question. First, the scale given for the map must be converted to square miles: since 1 inch is 60 miles, 1 square inch = 60 x 60 = 3600 square miles.

The proportion for the number of square miles the pilot surveys is:

1 square inch/3600 square miles = 4π square inches/x

Cross multiplying, we have:

x = 4π x 3600

x = 14,400 π square miles


Answer: E
GMAT Club Bot
gmatclubot
Re: A pilot surveys a flat circular area represented by 4π square inches [#permalink]
17 Nov 2017, 14:27
Moderators:
Bunuel
Math Expert
92915 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions