It is currently 15 Dec 2017, 02:28

# Decision(s) Day!:

CHAT Rooms | Wharton R1 | Stanford R1 | Tuck R1 | Ross R1 | Haas R1 | UCLA R1

### 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 June
Open Detailed Calendar

# The length of the edging that surrounds circular garden K is

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

### Hide Tags

Manager
Joined: 02 Dec 2012
Posts: 178

Kudos [?]: 3654 [0], given: 0

The length of the edging that surrounds circular garden K is [#permalink]

### Show Tags

13 Dec 2012, 05:53
3
This post was
BOOKMARKED
00:00

Difficulty:

5% (low)

Question Stats:

89% (01:05) correct 11% (01:06) wrong based on 839 sessions

### HideShow timer Statistics

The length of the edging that surrounds circular garden K is 1/2 the length of the edging that surrounds circular garden G. What is the area of garden K (Assume that the edging has negligible width.)

(1) The area of G is $$25\pi$$ square meters.
(2) The edging around G is $$10\pi$$ meters long.
[Reveal] Spoiler: OA

Kudos [?]: 3654 [0], given: 0

Math Expert
Joined: 02 Sep 2009
Posts: 42620

Kudos [?]: 135696 [0], given: 12706

Re: The length of the edging that surrounds circular garden K is [#permalink]

### Show Tags

13 Dec 2012, 05:57
Expert's post
2
This post was
BOOKMARKED
The length of the edging that surrounds circular garden K is 1/2 the length of the edging that surrounds circular garden G. What is the area of garden K (Assume that the edging has negligible width.)

Given that the circumference of garden K is 1/2 of the circumference of garden G, thus the radius of garden is K is 1/2 of the radius of garden G.

We need to find the area of garden K.

(1) The area of G is $$25\pi$$ square meters --> we can find the radius of garden G, thus we can find the radius of garden K, hence its area too. Sufficient.

(2) The edging around G is $$10\pi$$ meters long --> the circumference of garden G is $$10\pi$$. The same here: we can find the radius of garden G, thus we can find the radius of garden K, hence its area too. Sufficient.

_________________

Kudos [?]: 135696 [0], given: 12706

VP
Status: Been a long time guys...
Joined: 03 Feb 2011
Posts: 1375

Kudos [?]: 1721 [0], given: 62

Location: United States (NY)
Concentration: Finance, Marketing
GPA: 3.75
Re: The length of the edging that surrounds circular garden K is [#permalink]

### Show Tags

13 Dec 2012, 06:00
Both the statements are the same in that they both tell us the radius of G.
So the answer can either be D or E.
Since you can get the radius of G, so its circumference will be 10pi.
The circumference of K is half of that of G, that is 5pi. From this you can find out the radius and hence the area.
+1D
_________________

Kudos [?]: 1721 [0], given: 62

Director
Joined: 10 Mar 2013
Posts: 589

Kudos [?]: 494 [0], given: 200

Location: Germany
Concentration: Finance, Entrepreneurship
GMAT 1: 580 Q46 V24
GPA: 3.88
WE: Information Technology (Consulting)
Re: The length of the edging that surrounds circular garden K is [#permalink]

### Show Tags

14 Jul 2015, 04:20
When you can find a radius, then you can calculate both area and circumference of a circle. (D)
_________________

When you’re up, your friends know who you are. When you’re down, you know who your friends are.

Share some Kudos, if my posts help you. Thank you !

800Score ONLY QUANT CAT1 51, CAT2 50, CAT3 50
GMAT PREP 670
MGMAT CAT 630
KAPLAN CAT 660

Kudos [?]: 494 [0], given: 200

Intern
Joined: 10 Aug 2015
Posts: 31

Kudos [?]: 7 [0], given: 231

Location: India
GMAT 1: 700 Q48 V38
GPA: 3.5
WE: Consulting (Computer Software)
Re: The length of the edging that surrounds circular garden K is [#permalink]

### Show Tags

30 Apr 2016, 19:37
The length of the edging that surrounds circular garden K is 1/2 the length of the edging that surrounds circular garden G. What is the area of garden K (Assume that the edging has negligible width.)

(1) The area of G is $$25\pi$$ square meters.
(2) The edging around G is $$10\pi$$ meters long.

The question is very easy and above solutions are excellent. Just want to highlight one part the ratio of two circles circumference = the ratio of their radii, a fact that is very clear to see and saves us time.

Kudos [?]: 7 [0], given: 231

Target Test Prep Representative
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 1810

Kudos [?]: 981 [0], given: 5

Re: The length of the edging that surrounds circular garden K is [#permalink]

### Show Tags

14 May 2016, 06:42
The length of the edging that surrounds circular garden K is 1/2 the length of the edging that surrounds circular garden G. What is the area of garden K (Assume that the edging has negligible width.)

(1) The area of G is $$25\pi$$ square meters.
(2) The edging around G is $$10\pi$$ meters long.

Solution:

We are given that the length of edging that surrounds circular garden K is ½ the length of the edging that surrounds circular garden G. Since the gardens are circular, we know that the circumference of garden K is ½ the circumference of circular garden G. We will use the circumference formula C = 2∏r. If we let G = the radius of garden G, and K = the radius of garden K, we can create the following equation.

2∏K = ½(2∏G)

We need to determine the area of garden K, using the area formula A = ∏r^2. Since K = the radius of garden K, we know:

Area of garden K = ∏K^2

Thus, if we can determine the value of K, we can determine the area of garden K.

Statement One Alone:

The area of G is 25∏ square meters.

We can use the information in statement one to determine the value of the radius of garden G.

25∏ = ∏G^2

25 = G^2

√25 = √G^2

5 = G

Since we have the value of G, we can determine the circumference of garden G.

circumference of garden G = 2∏G

circumference = 2∏ x 5

circumference = 10∏

From the given information we also know that:

2∏K = ½(2∏G)

Since 10∏ is the circumference of garden G, we can substitute 10∏ for 2∏G in the equation 2∏K = ½(2∏G). We can now determine a value for K.

2∏K = ½(10∏)

2∏K = 5∏

K = 2.5

Since the radius of garden K is 2.5, we have enough information to determine the area of garden K. Statement one alone is sufficient to answer the question. We can eliminate answer choices B, C, and E.

Statement Two Alone:

The edging around G is 10∏ meters long.

Using the information in statement two, we know that the circumference of garden G is 10∏.

Recall that in statement one, we already determined that the circumference of garden G is 10∏. This is enough information to determine the radius of garden K and hence the area of garden K. Statement two alone is also sufficient to answer the question.

The answer is D.
_________________

Jeffery Miller
Head of GMAT Instruction

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

Kudos [?]: 981 [0], given: 5

Current Student
Joined: 02 May 2015
Posts: 260

Kudos [?]: 91 [0], given: 23

Location: South Africa
Concentration: International Business, Organizational Behavior
GPA: 3.49
WE: Web Development (Insurance)
Re: The length of the edging that surrounds circular garden K is [#permalink]

### Show Tags

24 May 2016, 03:57
Solving DS questions is a really big waste of time

radius can't be -ve. So we just have to make sure that we've one +ve rad-g

A) area given. One +ve soln. Enough
2) rad of g can be derived directly.

D
_________________

Kudos if I helped

Kudos [?]: 91 [0], given: 23

Non-Human User
Joined: 09 Sep 2013
Posts: 14830

Kudos [?]: 287 [0], given: 0

Re: The length of the edging that surrounds circular garden K is [#permalink]

### Show Tags

14 Nov 2017, 06:55
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________

Kudos [?]: 287 [0], given: 0

Re: The length of the edging that surrounds circular garden K is   [#permalink] 14 Nov 2017, 06:55
Display posts from previous: Sort by

# The length of the edging that surrounds circular garden K is

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

 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®.