BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
Vote for Target Test Prep, Newsweek Readers’ Choice Awards 2026
NEWSWEEK READERS’ CHOICE 2026

BIG NEWS! Target Test Prep has been nominated, and they’d love your vote!

TTP has worked incredibly hard to build the best test prep experience possible, and winning Newsweek’s 2026 Readers’ Choice Award for Best Test Prep would mean a lot to them. If TTP has helped you, they’d be incredibly grateful for your vote. You can vote once each day through September 9.

Vote for TTP
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

C is a circle...

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 238
Joined: Tue Feb 10, 2009 8:44 am
Thanked: 9 times
by avenus » Sun May 03, 2009 6:41 am
C is a circle with center D and radius 2. E is a circle with center F and radius R. Are there any points that are on both E and C?

1)distance from D to F is R+1
2)R=3
Last edited by avenus on Sun May 03, 2009 8:50 am, edited 1 time in total.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
Legendary Member
Posts: 1035
Joined: Wed Aug 27, 2008 10:56 pmFollowed by: 1 member
Thanked: 104 times

by scoobydooby » Sun May 03, 2009 8:08 am
avenus,
is there are a typo in the question? the question as is seems weird-statement 1) does it say distance between the centers of the circles ie distance between D and F?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 238
Joined: Tue Feb 10, 2009 8:44 am
Thanked: 9 times

by avenus » Sun May 03, 2009 8:51 am
scoobydooby wrote:avenus,
is there are a typo in the question? the question as is seems weird-statement 1) does it say distance between the centers of the circles ie distance between D and F?
you're right. I've corrected it.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 1035
Joined: Wed Aug 27, 2008 10:56 pmFollowed by: 1 member
Thanked: 104 times

by scoobydooby » Sun May 03, 2009 10:12 am
1) distance from D to F is R+1
=>if R is 1, then F lies on the circle C and circle C and circle E intersect, there are points on both circles.

if R is say 0.1, then circle E lies inside circle C, no points lie on both circle.
not sufficient

2)R=3
will not have points common to both circle if circles are concentric. circles may be tangent to each other or may intersect each other
not sufficient

together,
distance between D and F is 4, circle E intersects the circle C and passes through mid point of radius of C
=> circles C and E have points in common

hence, C
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 322
Joined: Fri Mar 27, 2009 3:56 pm
Thanked: 24 times
GMAT Score:710

by mike22629 » Sun May 03, 2009 11:34 am
Hmm.

I think that it is A.

What is OA?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 238
Joined: Tue Feb 10, 2009 8:44 am
Thanked: 9 times

by avenus » Mon May 04, 2009 2:18 am
OA is C. I went for A but there's an issue here with the definition of circle. This is what Cambridge's dictionary says about circle:


circle (SHAPE) noun [C]

a continuous curved line, the points of which are always the same distance away from a fixed central point, or the area enclosed by such a line:

Coloured paper was cut into circles, squares and triangles.
We sat in a circle


Depending on which of the two definitions we consider, the answer would be different. So how do we remove the ambiguity?
Any thoughts?
Last edited by avenus on Mon May 04, 2009 1:21 pm, edited 1 time in total.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 322
Joined: Fri Mar 27, 2009 3:56 pm
Thanked: 24 times
GMAT Score:710

by mike22629 » Mon May 04, 2009 9:18 am
I do not understand. Can someone explain further.

The way I see it, no matter what, the end of R has to be only 1 away from the center of the other circle, because R+1 is distance. Therefore, even if R is smallest fraction, it will just be entirely inside the circle.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 174
Joined: Thu Jan 08, 2009 12:04 am
Thanked: 5 times
GMAT Score:620

by bmlaud » Mon May 04, 2009 10:10 am
The distance between the centres of two circles will determine whether circles intersect or not.
if distance > R + 2 -- non intersecting circles
= R+2-- intersecting at a point
< R+2-- circles intersecting at two points
= 0 --- concentric circles
stat1: distance = R+1 => circles intersect
stat2: R=3 but what's the distance between centres? - can't say
Thus A
"Great works are performed not by strength but by perseverance."
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 238
Joined: Tue Feb 10, 2009 8:44 am
Thanked: 9 times

by avenus » Mon May 04, 2009 10:32 am
mike22629 wrote:I do not understand. Can someone explain further.

The way I see it, no matter what, the end of R has to be only 1 away from the center of the other circle, because R+1 is distance. Therefore, even if R is smallest fraction, it will just be entirely inside the circle.
Mike,

I think you're considering the second definition i talked about in my previous post, i.e., circle as the area enclosed in the curved line. If you consider circle as the curved line, then, if R>= 1/2, the two circles (curved lines) will intersect. However, if R< 1/2, F will be inside D (the case you describe) and there's no intersection between the two circles (curved lines).
Does that help?

Anyway, what about the ambiguity posed by the two possible definitions I've mentioned? Who wants to throw some light upon that?
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 435
Joined: Sat Sep 27, 2008 2:02 pmFollowed by: 1 member
Location: San Jose, CA
Thanked: 43 times
GMAT Score:720

by dumb.doofus » Mon May 04, 2009 12:34 pm
I think the answer is A

I say so because:

1. Question is not asking if the circles intersect.
2. Question is only asking if there are points that lie on both the circles.

Because it is given that the distance between the center of the circles is R+1, no matter what value of R you take, there will be points that are common to both the circles.
One love, one blood, one life. You got to do what you should.
https://dreambigdreamhigh.blocked/
https://gmattoughies.blocked/
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 238
Joined: Tue Feb 10, 2009 8:44 am
Thanked: 9 times

by avenus » Mon May 04, 2009 1:17 pm
dumb.doofus wrote: 1. Question is not asking if the circles intersect.
2. Question is only asking if there are points that lie on both the circles.
...so what's the difference? If they intersect they obviously have points in common, and vice versa; not sure I understand what you mean.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 431
Joined: Sat Jan 10, 2009 9:32 amFollowed by: 1 member
Thanked: 16 times

by kanha81 » Mon May 04, 2009 1:32 pm
scoobydooby wrote:1) distance from D to F is R+1
=>if R is 1, then F lies on the circle C and circle C and circle E intersect, there are points on both circles.

if R is say 0.1, then circle E lies inside circle C, no points lie on both circle.
not sufficient

2)R=3
will not have points common to both circle if circles are concentric. circles may be tangent to each other or may intersect each other
not sufficient

together,
distance between D and F is 4, circle E intersects the circle C and passes through mid point of radius of C
=> circles C and E have points in common

hence, C
scooby dooby,

I tried to understand your solution, but could not. Is there a way you could explain using a diagram? I tried to sketch the diagram for-


a) 2 circles meet at 1 point
b) Circle C is bigger than circle E and they meet at 1 point

Insuff?
Want to Beat GMAT.
Always do what you're afraid to do. Whoooop GMAT
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 36
Joined: Tue May 05, 2009 1:20 am
Thanked: 2 times

by benissleeping » Tue May 05, 2009 1:41 am
kanha81 wrote:
scoobydooby wrote:1) distance from D to F is R+1
=>if R is 1, then F lies on the circle C and circle C and circle E intersect, there are points on both circles.

if R is say 0.1, then circle E lies inside circle C, no points lie on both circle.
not sufficient

2)R=3
will not have points common to both circle if circles are concentric. circles may be tangent to each other or may intersect each other
not sufficient

together,
distance between D and F is 4, circle E intersects the circle C and passes through mid point of radius of C
=> circles C and E have points in common

hence, C
scooby dooby,

I tried to understand your solution, but could not. Is there a way you could explain using a diagram? I tried to sketch the diagram for-


a) 2 circles meet at 1 point
b) Circle C is bigger than circle E and they meet at 1 point

Insuff?


Took me a little while but I get it now.

Draw circle C with center D and radius 2. Now assume R=0.1.

Draw center F which is 1.1 from center D. Now draw circle E with radius 0.1 from center F.

You will see that circle E lies completely inside circle C and there are no points common.

As discussed above, the answer will be C.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1