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

 It is currently 22 Feb 2019, 14:41

### 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 February
PrevNext
SuMoTuWeThFrSa
272829303112
3456789
10111213141516
17181920212223
242526272812
Open Detailed Calendar
• ### Free GMAT RC Webinar

February 23, 2019

February 23, 2019

07:00 AM PST

09:00 AM PST

Learn reading strategies that can help even non-voracious reader to master GMAT RC. Saturday, February 23rd at 7 AM PT
• ### FREE Quant Workshop by e-GMAT!

February 24, 2019

February 24, 2019

07:00 AM PST

09:00 AM PST

Get personalized insights on how to achieve your Target Quant Score.

# A and B are centers of two circles that touch each other externally

Author Message
TAGS:

### Hide Tags

Math Expert
Joined: 02 Sep 2009
Posts: 53066
A and B are centers of two circles that touch each other externally  [#permalink]

### Show Tags

09 Oct 2018, 22:33
00:00

Difficulty:

15% (low)

Question Stats:

93% (00:56) correct 7% (00:36) wrong based on 25 sessions

### HideShow timer Statistics

A and B are centers of two circles that touch each other externally, as shown in the figure. What is the area of the circle whose diameter is AB ?

(A) $$4\pi$$

(B) $$\frac{25\pi}{4}$$

(C) $$9\pi$$

(D) $$16\pi$$

(E) $$25\pi$$

Attachment:

circles.jpg [ 26.87 KiB | Viewed 338 times ]

_________________
CEO
Status: GMATINSIGHT Tutor
Joined: 08 Jul 2010
Posts: 2799
Location: India
GMAT: INSIGHT
Schools: Darden '21
WE: Education (Education)
Re: A and B are centers of two circles that touch each other externally  [#permalink]

### Show Tags

10 Oct 2018, 00:24
Bunuel wrote:

A and B are centers of two circles that touch each other externally, as shown in the figure. What is the area of the circle whose diameter is AB ?

(A) $$4\pi$$

(B) $$\frac{25\pi}{4}$$

(C) $$9\pi$$

(D) $$16\pi$$

(E) $$25\pi$$

Attachment:
circles.jpg

From the figure it may be inferred that AB = 5

i.e. Diameter of Circle = 5

$$Area = πr^2 = π(5/2)^2 = (25/4)π$$

_________________

Prosper!!!
GMATinsight
Bhoopendra Singh and Dr.Sushma Jha
e-mail: info@GMATinsight.com I Call us : +91-9999687183 / 9891333772
Online One-on-One Skype based classes and Classroom Coaching in South and West Delhi
http://www.GMATinsight.com/testimonials.html

ACCESS FREE GMAT TESTS HERE:22 ONLINE FREE (FULL LENGTH) GMAT CAT (PRACTICE TESTS) LINK COLLECTION

Manager
Joined: 06 Sep 2018
Posts: 175
Location: Pakistan
Concentration: Finance, Operations
GPA: 2.87
WE: Engineering (Other)
Re: A and B are centers of two circles that touch each other externally  [#permalink]

### Show Tags

10 Oct 2018, 00:41
As shown in the attachment:
Diameter of red circle is $$D=2+3=5$$
so radius is $$r=\frac{5}{2}$$
Area of circle is $$A=πr^2$$
$$A=π*(\frac{5}{2})^2$$
$$A= \frac{25π}{4}$$
Attachments

Capture.PNG [ 29.18 KiB | Viewed 233 times ]

_________________

Hitting Kudos is the best way of appreciation.

Eric Thomas, "When you want to succeed as bad as you want to breathe, then you'll be successful."

Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 4960
Location: United States (CA)
Re: A and B are centers of two circles that touch each other externally  [#permalink]

### Show Tags

13 Oct 2018, 17:33
Bunuel wrote:

A and B are centers of two circles that touch each other externally, as shown in the figure. What is the area of the circle whose diameter is AB ?

(A) $$4\pi$$

(B) $$\frac{25\pi}{4}$$

(C) $$9\pi$$

(D) $$16\pi$$

(E) $$25\pi$$

Attachment:
circles.jpg

Since the diameter of circle AB is 5, the radius is 5/2, and thus the area is (5/2)^2 x ? = 25?/4.

_________________

Scott Woodbury-Stewart
Founder and CEO

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Re: A and B are centers of two circles that touch each other externally   [#permalink] 13 Oct 2018, 17:33
Display posts from previous: Sort by