GRE Prep 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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
A and B are centers of two circles that touch each other ext
[#permalink]
03 Oct 2018, 06:57
03 Oct 2018, 06:57
1
Expert Reply
00:00
Question Stats:
95% (00:43) correct
4% (00:00) wrong based on 24 sessions
Hide Show timer Statistics
Attachment:
#GREpracticequestion A and B are centers of two circles that touch.jpg [ 26.87 KiB | Viewed 4602 times ]
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) \(25\pi\)
Re: A and B are centers of two circles that touch each other ext
[#permalink]
12 Feb 2019, 21:33
12 Feb 2019, 21:33
1
Expert Reply
The line segment AB = 5
the area of the circle with AB as its diameter means that the area of a circle with a diameter of 5.
the area of a circle is Pi*radius^2, or pi*r^2
the radius is half the diameter, so then r = 5/2
then the area is
Pi*(5/2)^2= Pi*25/4
The answer is B
the area of the circle with AB as its diameter means that the area of a circle with a diameter of 5.
the area of a circle is Pi*radius^2, or pi*r^2
the radius is half the diameter, so then r = 5/2
then the area is
Pi*(5/2)^2= Pi*25/4
The answer is B
Moderator
Joined: 02 Jan 2020
Status:GRE Quant Tutor
Posts: 1131
Given Kudos: 9
Location: India
Concentration: General Management
Schools: XLRI Jamshedpur, India - Class of 2014
GMAT 1: 700 Q51 V31
GPA: 2.8
WE:Engineering (Computer Software)
A and B are centers of two circles that touch each other ext
[#permalink]
06 Jun 2021, 08:48
06 Jun 2021, 08:48
1
A and B are centers of two circles that touch each other externally => Length of AB = 2+3 = 5
Now AB is the diameter of the new circle => Radius = \(\frac{1}{2}\) * AB = \(\frac{5}{2}\)
We know that Area of Circle = \(\pi\)\(r^2\) = \(\pi\)\((\frac{5}{2})^2\) = \(\pi\)\(\frac{25}{4}\) = \(\frac{25\pi}{4}\)
So, Answer will be B
Hope it helps!
Watch the following video to Learn Basics of Circles
Now AB is the diameter of the new circle => Radius = \(\frac{1}{2}\) * AB = \(\frac{5}{2}\)
We know that Area of Circle = \(\pi\)\(r^2\) = \(\pi\)\((\frac{5}{2})^2\) = \(\pi\)\(\frac{25}{4}\) = \(\frac{25\pi}{4}\)
So, Answer will be B
Hope it helps!
Watch the following video to Learn Basics of Circles
