Last visit was: 23 Apr 2026, 11:11 It is currently 23 Apr 2026, 11:11
Home
Messages
Tests
Schools
Events
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
User avatar
noboru
User avatar
Joined: 16 Jul 2009
Last visit: 15 Jan 2020
Posts: 538
Own Kudos:
9,613
Given Kudos: 2
Schools:CBS
WE 1: 4 years (Consulting)
Posts: 538
Kudos: 9,613
geometry_Hard one 13 Sep 2009, 12:38
Kudos
Add Kudos
Bookmarks
Bookmark this Post
00:00
Start Timer
Pause Timer
Resume Timer
Show Answer
Hide
Show
History
N
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

History

Date
Time
Result
Not Attempted Yet
Attached.



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
User avatar
Jivana
User avatar
Joined: 20 Mar 2008
Last visit: 26 Apr 2011
Posts: 339
Own Kudos:
441
Given Kudos: 5
Posts: 339
Kudos: 441
geometry_Hard one 13 Sep 2009, 13:22
Kudos
Add Kudos
Bookmarks
Bookmark this Post
A is sufficient as well.

let oab = x, boa = x
let obc = y, ocb = y
let boc = z

Since cod = 60, x + z = 180-60 = 120
z = 120 - x

Since, abo = 180 - y, and abo = 180 - 2x
or, y = 2x

Now, in boc, z = 180 - 2y = 180 - 2.2x = 180 - 4x

Since, z = 120 - x,
120 - x = 180 - 4x
Solving, 3x = 60...
or, x = 20.
avatar
anish319
avatar
Joined: 04 May 2009
Last visit: 18 Jan 2018
Posts: 24
Own Kudos:
55
Given Kudos: 1
Location: Astoria, NYC
Posts: 24
Kudos: 55
geometry_Hard one 15 Sep 2009, 07:52
Kudos
Add Kudos
Bookmarks
Bookmark this Post
where are you getting this statement from....am I missing something

"Since, abo = 180 - y, and abo = 180 - 2x
or, y = 2x"
User avatar
deepakraam
User avatar
Joined: 15 Sep 2009
Last visit: 27 Oct 2011
Posts: 54
Own Kudos:
56
Given Kudos: 2
Posts: 54
Kudos: 56
geometry_Hard one 15 Sep 2009, 08:11
Kudos
Add Kudos
Bookmarks
Bookmark this Post
i wud go with option D.

Statement 1:
==========
OB,OC,OD will all be equal since the distance becomes the radius of the semi-circle.From the q it is also known tht AB=OC=radius.

So either statements gives the angle between the radius.The q also asks about the angle b/w the radius.

So,I wud go with option D
User avatar
Jivana
User avatar
Joined: 20 Mar 2008
Last visit: 26 Apr 2011
Posts: 339
Own Kudos:
441
Given Kudos: 5
Posts: 339
Kudos: 441
geometry_Hard one 15 Sep 2009, 08:36
Kudos
Add Kudos
Bookmarks
Bookmark this Post
anish319
where are you getting this statement from....am I missing something

"Since, abo = 180 - y, and abo = 180 - 2x
or, y = 2x"
Show more

abc is a st. line, therefore abo + obc = 180
or, abo + y = 180
or, abo = 180 - y

Also, since abo is a trinagle, the sum of all angles must be 180.

Therfore,
abo = 180 - bao - oba
= 180 - x - x
= 180 - 2x
User avatar
sprtng
User avatar
Joined: 17 Jul 2009
Last visit: 13 May 2014
Posts: 74
Own Kudos:
107
Given Kudos: 9
Concentration: Nonprofit, Strategy
Schools: Yale '16 (D) Haas '16 (WL) Duke '16 (WL) Tuck '16 (WL)
GPA: 3.42
WE:Engineering (Computer Hardware)
Schools: Yale '16 (D) Haas '16 (WL) Duke '16 (WL) Tuck '16 (WL)
Posts: 74
Kudos: 107
geometry_Hard one 15 Sep 2009, 17:36
Kudos
Add Kudos
Bookmarks
Bookmark this Post
if the question states that AOC is a triangle, then i choose D. otherwise, E.

if AOC is a triangle, which means assuming AC is a straight line, then we have (all angles from this point on)

OCB = OBC = 2A

statement 1:
COD = 60

which means OCB + A = 60 => 3A = 60 => A = 20

statement 2:
BCO = 40

BCO = 2A = 40 =>　Ａ = 20



Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
Moderator:
Bunuel
Math Expert
109783 posts