GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 17 Oct 2019, 01:10

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

Point O is the center of the circle. If the area of the circle is 36π

Author Message
TAGS:

Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 58427
Point O is the center of the circle. If the area of the circle is 36π  [#permalink]

Show Tags

21 Dec 2018, 02:39
00:00

Difficulty:

25% (medium)

Question Stats:

83% (00:54) correct 17% (00:52) wrong based on 31 sessions

HideShow timer Statistics

Point O is the center of the circle. If the area of the circle is 36π and the area of the rectangle is 72, what is the length of DC?

A. 4
B. 6
C. 8
D. 10
E. 12

Attachment:

Capture (7).JPG [ 28.15 KiB | Viewed 373 times ]

_________________
GMAT Club Legend
Joined: 18 Aug 2017
Posts: 5003
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
Re: Point O is the center of the circle. If the area of the circle is 36π  [#permalink]

Show Tags

21 Dec 2018, 03:21
area of circle = 36 pi

OD and OA = 6

rectanle we can say 6*x= 72
x= 12

so since OD= 6 ; DC = 12-6 = 6 IMO B

Bunuel wrote:

Point O is the center of the circle. If the area of the circle is 36π and the area of the rectangle is 72, what is the length of DC?

A. 4
B. 6
C. 8
D. 10
E. 12

Attachment:
Capture (7).JPG
e-GMAT Representative
Joined: 04 Jan 2015
Posts: 3074
Point O is the center of the circle. If the area of the circle is 36π  [#permalink]

Show Tags

21 Dec 2018, 05:49

Solution

Given:
• O is the center of the circle
• Area of the circle = 36ᴨ
• Area of the rectangle = 72

To find:
• The length of DC

Approach and Working:
Area of the circle = $$ᴨr^2 = 36 ᴨ$$
• Thus, r = 6

Breadth of the rectangle = OA, which is the radius of the circle = 6
• We know, l * b = 72
• Thus, $$l = \frac{72}{6} = 12 = OC$$

OC = OD + DC = 6 + DC

Therefore, DC= 12 – 6 = 6

Hence, the correct answer is Option B

_________________
Point O is the center of the circle. If the area of the circle is 36π   [#permalink] 21 Dec 2018, 05:49
Display posts from previous: Sort by