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

It is currently 15 Oct 2018, 23:07

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

There are three circles, with radii 2, 4 and 5, respectively

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Senior Manager
Senior Manager
avatar
Joined: 10 Apr 2012
Posts: 269
Location: United States
Concentration: Technology, Other
GPA: 2.44
WE: Project Management (Telecommunications)
GMAT ToolKit User Premium Member
There are three circles, with radii 2, 4 and 5, respectively  [#permalink]

Show Tags

New post 15 Jun 2013, 13:26
2
4
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

76% (00:51) correct 24% (01:19) wrong based on 172 sessions

HideShow timer Statistics

There are three circles, with radii 2, 4 and 5, respectively, that lie on a plane. Do any two of these circles intersect with each other?

(1) The centres of the three circles lie on a straight line

(2) The greatest distance between the centres of any two of these circles is 7
VP
VP
User avatar
Status: Far, far away!
Joined: 02 Sep 2012
Posts: 1077
Location: Italy
Concentration: Finance, Entrepreneurship
GPA: 3.8
GMAT ToolKit User
Re: There are three circles, with radii 2, 4 and 5, respectively  [#permalink]

Show Tags

New post 15 Jun 2013, 13:43
1
There are three circles, with radii 2, 4 and 5, respectively, that lie on a plane. Do any two of these circles intersect with each other?

(1) The centres of the three circles lie on a straight line
Not sufficient. Consider the case in which, even on the same line they are 1 away from each other ( hence they intersect) or the case in which they are 100 away from each other (hence they do not intersect)

(2) The greatest distance between the centres of any two of these circles is 7
Since even the distance between the 4 and 5 radius circle is 7, they will intersect. Those two circles intersect because the distance between their centers is less than 4+5=9.
Sufficient
_________________

It is beyond a doubt that all our knowledge that begins with experience.

Kant , Critique of Pure Reason

Tips and tricks: Inequalities , Mixture | Review: MGMAT workshop
Strategy: SmartGMAT v1.0 | Questions: Verbal challenge SC I-II- CR New SC set out !! , My Quant

Rules for Posting in the Verbal Forum - Rules for Posting in the Quant Forum[/size][/color][/b]

Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49860
Re: There are three circles, with radii 2, 4 and 5, respectively  [#permalink]

Show Tags

New post 15 Jun 2013, 13:55
2
1
guerrero25 wrote:
There are three circles, with radii 2, 4 and 5, respectively, that lie on a plane. Do any two of these circles intersect with each other?

(1) The centres of the three circles lie on a straight line

(2) The greatest distance between the centres of any two of these circles is 7


Below diagram might help:
Attachment:
Circles.png
Circles.png [ 12.21 KiB | Viewed 2974 times ]
Even in this case two circles intersect.

Similar questions to practice:
if-x-and-y-are-points-in-a-plane-and-x-lies-inside-the-135194.html (OG13)
a-certain-circular-area-has-its-center-at-point-p-and-has-101485.html (GMAT Prep)
circle-c-is-in-the-xy-plane-what-is-the-area-of-the-circle-99766.html
in-the-figure-shown-the-circle-has-center-o-and-radius-107309.html
on-the-number-line-shown-is-zero-halfway-between-r-and-s-89015.html
is-the-radius-of-the-circle-greater-than-105060.html
if-point-x-is-inside-a-circle-with-center-o-and-radius-2-is-102751.html
if-a-and-c-are-points-in-a-plane-c-is-the-center-of-circle-133325.html

Hope it helps.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 29 May 2013
Posts: 8
Concentration: Operations, Strategy
Schools: ISB '15
GMAT ToolKit User
Re: There are three circles, with radii 2, 4 and 5, respectively  [#permalink]

Show Tags

New post 05 Nov 2013, 09:58
Bunuel wrote:
guerrero25 wrote:
There are three circles, with radii 2, 4 and 5, respectively, that lie on a plane. Do any two of these circles intersect with each other?

(1) The centres of the three circles lie on a straight line

(2) The greatest distance between the centres of any two of these circles is 7


Below diagram might help:
Attachment:
Circles.png
Even in this case two circles intersect.

Similar questions to practice:
if-x-and-y-are-points-in-a-plane-and-x-lies-inside-the-135194.html (OG13)
a-certain-circular-area-has-its-center-at-point-p-and-has-101485.html (GMAT Prep)
circle-c-is-in-the-xy-plane-what-is-the-area-of-the-circle-99766.html
in-the-figure-shown-the-circle-has-center-o-and-radius-107309.html
on-the-number-line-shown-is-zero-halfway-between-r-and-s-89015.html
is-the-radius-of-the-circle-greater-than-105060.html
if-point-x-is-inside-a-circle-with-center-o-and-radius-2-is-102751.html
if-a-and-c-are-points-in-a-plane-c-is-the-center-of-circle-133325.html

Hope it helps.



Dear Bunuel,

What if centers of circles are
5 radius : (0,0)
4 radius : (0.5,0)
2 radius : (1,0)

Here, Centers are on straight line but circles are not intersecting. Hence it should be E right?

Thank you
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49860
Re: There are three circles, with radii 2, 4 and 5, respectively  [#permalink]

Show Tags

New post 05 Nov 2013, 10:05
Shashank1149 wrote:
Bunuel wrote:
guerrero25 wrote:
There are three circles, with radii 2, 4 and 5, respectively, that lie on a plane. Do any two of these circles intersect with each other?

(1) The centres of the three circles lie on a straight line

(2) The greatest distance between the centres of any two of these circles is 7


Below diagram might help:
Attachment:
Circles.png
Even in this case two circles intersect.

Similar questions to practice:
if-x-and-y-are-points-in-a-plane-and-x-lies-inside-the-135194.html (OG13)
a-certain-circular-area-has-its-center-at-point-p-and-has-101485.html (GMAT Prep)
circle-c-is-in-the-xy-plane-what-is-the-area-of-the-circle-99766.html
in-the-figure-shown-the-circle-has-center-o-and-radius-107309.html
on-the-number-line-shown-is-zero-halfway-between-r-and-s-89015.html
is-the-radius-of-the-circle-greater-than-105060.html
if-point-x-is-inside-a-circle-with-center-o-and-radius-2-is-102751.html
if-a-and-c-are-points-in-a-plane-c-is-the-center-of-circle-133325.html

Hope it helps.



Dear Bunuel,

What if centers of circles are
5 radius : (0,0)
4 radius : (0.5,0)
2 radius : (1,0)

Here, Centers are on straight line but circles are not intersecting. Hence it should be E right?

Thank you


(2) says that the greatest distance between the centres of any two of these circles is 7. In your examples this condition is not met.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 29 May 2013
Posts: 8
Concentration: Operations, Strategy
Schools: ISB '15
GMAT ToolKit User
Re: There are three circles, with radii 2, 4 and 5, respectively  [#permalink]

Show Tags

New post 05 Nov 2013, 11:01
Bunuel wrote:
Shashank1149 wrote:
There are three circles, with radii 2, 4 and 5, respectively, that lie on a plane. Do any two of these circles intersect with each other?

(1) The centres of the three circles lie on a straight line

(2) The greatest distance between the centres of any two of these circles is 7

Below diagram might help:
Attachment:
Circles.png
Even in this case two circles intersect.

Similar questions to practice:
if-x-and-y-are-points-in-a-plane-and-x-lies-inside-the-135194.html (OG13)
a-certain-circular-area-has-its-center-at-point-p-and-has-101485.html (GMAT Prep)
circle-c-is-in-the-xy-plane-what-is-the-area-of-the-circle-99766.html
in-the-figure-shown-the-circle-has-center-o-and-radius-107309.html
on-the-number-line-shown-is-zero-halfway-between-r-and-s-89015.html
is-the-radius-of-the-circle-greater-than-105060.html
if-point-x-is-inside-a-circle-with-center-o-and-radius-2-is-102751.html
if-a-and-c-are-points-in-a-plane-c-is-the-center-of-circle-133325.html

Hope it helps


Dear Bunuel,

What if centers of circles are
5 radius : (0,0)
4 radius : (0.5,0)
2 radius : (1,0)

Here, Centers are on straight line but circles are not intersecting. Hence it should be E right?

Thank you


(2) says that the greatest distance between the centres of any two of these circles is 7. In your examples this condition is not met.
[/quote]

Dear Bunuel,

Sorry but I really didn't understand. It said GREATEST, that means distance can be zero to seven. I suppose in my example it's met. If it just said that the distance between any two circles is 7 then I guess your point is correct. Can you pls explain why GREATEST is not playing significant role here?

Thank you
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 49860
Re: There are three circles, with radii 2, 4 and 5, respectively  [#permalink]

Show Tags

New post 05 Nov 2013, 11:07
1
Shashank1149 wrote:
Dear Bunuel,

Sorry but I really didn't understand. It said GREATEST, that means distance can be zero to seven. I suppose in my example it's met. If it just said that the distance between any two circles is 7 then I guess your point is correct. Can you pls explain why GREATEST is not playing significant role here?

Thank you


You misinterpreted the statement. It means that the distance IS 7 between the centers of 2 particular circles of the 3 but the distance between any other two of these circles is not more than that.
_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

Intern
Intern
avatar
Joined: 20 Sep 2018
Posts: 4
Re: There are three circles, with radii 2, 4 and 5, respectively  [#permalink]

Show Tags

New post 29 Sep 2018, 15:51
guerrero25 wrote:
There are three circles, with radii 2, 4 and 5, respectively, that lie on a plane. Do any two of these circles intersect with each other?

(1) The centres of the three circles lie on a straight line

(2) The greatest distance between the centres of any two of these circles is 7



1 gives very little information

2 is a good trap but not sufficient because while it is clear that their areas may overlap, they may or may not overlap. Example- two may be concentric circles.

Combining also, the reasoning above in 2 keeps both yes and no possibility open.

E.

Good question but doesn't taste like GMAT.
Intern
Intern
avatar
Joined: 20 Sep 2018
Posts: 4
Re: There are three circles, with radii 2, 4 and 5, respectively  [#permalink]

Show Tags

New post 29 Sep 2018, 15:55
Ohhh, my bad. They are bound to touch for sure, using 2.

I am treating touching and intersecting as different but touching is a foreally of intersecting.

B it is.

Md231 wrote:
guerrero25 wrote:
There are three circles, with radii 2, 4 and 5, respectively, that lie on a plane. Do any two of these circles intersect with each other?

(1) The centres of the three circles lie on a straight line

(2) The greatest distance between the centres of any two of these circles is 7



1 gives very little information

2 is a good trap but not sufficient because while it is clear that their areas may overlap, they may or may not overlap. Example- two may be concentric circles.

Combining also, the reasoning above in 2 keeps both yes and no possibility open.

E.

Good question but doesn't taste like GMAT.
GMAT Club Bot
Re: There are three circles, with radii 2, 4 and 5, respectively &nbs [#permalink] 29 Sep 2018, 15:55
Display posts from previous: Sort by

There are three circles, with radii 2, 4 and 5, respectively

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.