It is currently 19 Mar 2018, 19:07

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# In the diagram above, O is the center of the circle

Author Message
TAGS:

### Hide Tags

Magoosh GMAT Instructor
Joined: 28 Dec 2011
Posts: 4678
In the diagram above, O is the center of the circle [#permalink]

### Show Tags

01 May 2013, 10:40
1
KUDOS
Expert's post
2
This post was
BOOKMARKED
00:00

Difficulty:

25% (medium)

Question Stats:

77% (01:01) correct 23% (01:17) wrong based on 163 sessions

### HideShow timer Statistics

Attachment:

circle with segments.png [ 14.94 KiB | Viewed 1935 times ]

In the diagram above, O is the center of the circle, DC = a and DO = b. What is the area of the circle?

Statement #1: $$a^2 - 2ab + b^2 = 36$$

Statement #2: a + b = 22

For a discussion of the important algebra formulas involved, as well as a full solution to this particular problem, see:
http://magoosh.com/gmat/2013/three-alge ... -the-gmat/
[Reveal] Spoiler: OA

_________________

Mike McGarry
Magoosh Test Prep

Education is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)

 Magoosh Discount Codes Economist GMAT Tutor Discount Codes Kaplan GMAT Prep Discount Codes
Manager
Joined: 26 Feb 2013
Posts: 53
Concentration: Strategy, General Management
GMAT 1: 660 Q50 V30
WE: Consulting (Telecommunications)
Re: In the diagram above, O is the center of the circle [#permalink]

### Show Tags

01 May 2013, 11:13
Option A.

DC= a and DO =b
OC= DC-DO = b-a = radius of the circle.

From stmt 1:
(b-a)^2=36 or (b-a)=6 and area = 36pi. sufficient

From stmt 2:

we know a+b but we need to know the value of b-a. hence this is insufficient.
Manager
Joined: 13 Dec 2013
Posts: 168
Location: United States (NY)
GMAT 1: 710 Q46 V41
GMAT 2: 720 Q48 V40
GPA: 4
WE: Consulting (Consulting)
Re: In the diagram above, O is the center of the circle [#permalink]

### Show Tags

15 Apr 2017, 17:29
Option A.

DC= a and DO =b
OC= DC-DO = b-a = radius of the circle.

From stmt 1:
(b-a)^2=36 or (b-a)=6 and area = 36pi. sufficient

From stmt 2:

we know a+b but we need to know the value of b-a. hence this is insufficient.

I believe it's (a-b) we're looking for here.

(a-b)(a-b)=r^2=36 So, area is 36pi
Re: In the diagram above, O is the center of the circle   [#permalink] 15 Apr 2017, 17:29
Display posts from previous: Sort by