Last visit was: 16 Nov 2024, 10:12 It is currently 16 Nov 2024, 10:12
Decision Tracker
My Rewards
New comers' posts
New posts
Unanswered

Close

GRE Prep 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 GRE 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
PREVIOUS TOPIC
NEXT TOPIC

If the circumference of circle O is 5 times the circum

Tags :
Find Similar Topics  About  Add a Tag

Show Tags
Hide Tags

User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 29962
Own Kudos [?]: 36246 [0]
Given Kudos: 25911
Send PM
If the circumference of circle O is 5 times the circum [#permalink] New post   07 Sep 2020, 04:55
Expert Reply
00:00

Question Stats:

95% (00:51) correct 4% (01:40) wrong based on 23 sessions

Hide Show timer Statistics

If the circumference of circle O is 5 times the circumference of circle O′, then the area of circle O is how many times the area of circle O′?


Show: :: OA
25 times
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 29962
Own Kudos [?]: 36246 [0]
Given Kudos: 25911
Send PM
Re: If the circumference of circle O is 5 times the circum [#permalink] New post   07 Sep 2020, 04:55
Expert Reply
Post A Detailed Correct Solution For The Above Questions And Get A Kudos.
Question From Our New Project: GRE Quant Challenge Questions Daily - NEW EDITION!

For more theory and practice see our GRE - Math Book
avatar
fraise
Intern
Intern
Joined: 17 Aug 2020
Posts: 40
Own Kudos [?]: 31 [0]
Given Kudos: 0
Send PM
Re: If the circumference of circle O is 5 times the circum [#permalink] New post   08 Sep 2020, 05:29
1
Is this the correct picture? Because I can't see O and O' in it... Thanks!
User avatar
D
Carcass
Verbal Expert
Joined: 18 Apr 2015
Posts: 29962
Own Kudos [?]: 36246 [0]
Given Kudos: 25911
Send PM
Re: If the circumference of circle O is 5 times the circum [#permalink] New post   08 Sep 2020, 05:37
Expert Reply
Sorry I have uploaded the wrong figure related to another question.

Thank you. Fixed
avatar
viju8307
Intern
Intern
Joined: 10 Sep 2020
Posts: 1
Own Kudos [?]: 1 [0]
Given Kudos: 0
Send PM
Re: If the circumference of circle O is 5 times the circum [#permalink] New post   11 Sep 2020, 01:52
1
Carcass wrote:
If the circumference of circle O is 5 times the circumference of circle O′, then the area of circle O is how many times the area of circle O′?


Show: :: OA
25 times



Circumference= 2*pi*r

let the radius of o' be 1, so circumference is 2*pi*1=2Pi
so the circumference of circle O is 5 times 2pi=10*pi

radius of circle O= sq rt (5)

(Area of O)/(area of O')= ((sq rt (5))^2)/1 = 25
User avatar
B
Pranaygre
Retired Moderator
Joined: 09 Jun 2020
Posts: 205
Own Kudos [?]: 235 [0]
Given Kudos: 34
GPA: 3.21
Send PM
Re: If the circumference of circle O is 5 times the circum [#permalink] New post   13 Sep 2020, 00:48
C1:C2 =5:1
this means
r1:r2 =5:1 (C=2π*r)
as A = πr²
A1:A2 = (5*5)/(1*1) = 25
so area of cirlce O is 25 times area of O'
(here suffix 1 is related to circle O and suffix 2 related to circle O')
Prep Club for GRE Bot
gmatclubot
Re: If the circumference of circle O is 5 times the circum [#permalink]
13 Sep 2020, 00:48
Moderators:
adewale223
GRE Instructor
78 posts
bronaugust
GRE Forum Moderator
37 posts
BrushMyQuant
Moderator
1111 posts
VibhuAnurag
GRE Instructor
234 posts

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

Main navigation

Partners

GRE Resources

www.ets.org/gre | About | Terms and Conditions and Privacy Policy | Prep Club for GRE Rules | Contact