BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

gmat prep

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 1460
Joined: Tue Dec 29, 2009 1:28 am
Thanked: 135 times
Followed by:7 members

by selango » Mon Oct 04, 2010 4:38 am
Length of arc ABC=2/3 *(Circumference of circle)

24=2/3*(2*Pi*r)=2/3(pi*d)

pi*d=36 or d=36/pi=11

Pick C
--Anand--
Top
Senior | Next Rank: 100 Posts
Posts: 78
Joined: Mon Sep 20, 2010 12:51 am

by girishbtg » Mon Oct 04, 2010 4:47 am
selango wrote:Length of arc ABC=2/3 *(Circumference of circle)

24=2/3*(2*Pi*r)=2/3(pi*d)

pi*d=36 or d=36/pi=11

Pick C

but how you can take this statement ->


Length of arc ABC=2/3 *(Circumference of circle) .....? why
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 1179
Joined: Sun Apr 11, 2010 9:07 pm
Location: Milpitas, CA
Thanked: 447 times
Followed by:88 members

by Rahul@gurome » Mon Oct 04, 2010 7:10 am
Angle inscribed by arc AC at the center of circle is twice the angle inscribed at any other point in the circle. So, angle inscribed by arc AC at the center of the circle = 2(60) = 120º
Image
Length of arc ABC = (240/360)*2(pi)(radius) = (2/3)*2(pi)*(r) = 24
We need to find the value of 2(r)
So, 2r = (24 * 3)/(2)*(pi) = 36/(pi) = 11 (appr.)

The correct answer is [spoiler](C)[/spoiler].
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Top
Master | Next Rank: 500 Posts
Posts: 155
Joined: Wed Sep 22, 2010 3:54 am
Thanked: 6 times

by pzazz12 » Tue Oct 05, 2010 3:51 am
Rahul@gurome wrote:Angle inscribed by arc AC at the center of circle is twice the angle inscribed at any other point in the circle. So, angle inscribed by arc AC at the center of the circle = 2(60) = 120º
Image
Length of arc ABC = (240/360)*2(pi)(radius) = (2/3)*2(pi)*(r) = 24
We need to find the value of 2(r)
So, 2r = (24 * 3)/(2)*(pi) = 36/(pi) = 11 (appr.)

The correct answer is [spoiler](C)[/spoiler].
thank you,but can you explain me little bit clear...
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 1179
Joined: Sun Apr 11, 2010 9:07 pm
Location: Milpitas, CA
Thanked: 447 times
Followed by:88 members

by Rahul@gurome » Tue Oct 05, 2010 3:57 am
pzazz12 wrote: thank you,but can you explain me little bit clear...
Angle inscribed by arc ABC at the center of circle = 240º (as explained earlier)
Angle at the center of the circle = 360º
Therefore, length of arc ABC = (240/360)*2(pi)(radius)

Hope that helps.
Rahul Lakhani
Quant Expert
Gurome, Inc.
https://www.GuroMe.com
On MBA sabbatical (at ISB) for 2011-12 - will stay active as time permits
1-800-566-4043 (USA)
+91-99201 32411 (India)
Top
Post new topic Post Reply
• Page 1 of 1