It is currently 22 Feb 2018, 14:52

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

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

A thin piece of wire 40 meters long is cut into two pieces.

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

Hide Tags

10 KUDOS received
Manager
Manager
avatar
Joined: 07 Feb 2010
Posts: 154
A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 21 Dec 2010, 07:20
10
This post received
KUDOS
63
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

67% (01:04) correct 33% (01:16) wrong based on 1328 sessions

HideShow timer Statistics

A thin piece of wire 40 meters long is cut into two pieces. One piece is used to form a circle with radius r, and the other is used to form a square. No wire is left over. Which of the following represents the total area, in square meters, of the circular and the square regions in terms of r?

A. \(\pi*r^2\)
B. \(\pi*r^2 + 10\)
C. \(\pi*r^2 + \frac{1}{4}*\pi^2*r^2\)
D. \(\pi*r^2 + (40 - 2\pi*r)^2\)
E. \(\pi*r^2 + (10 - \frac{1}{2}\pi*r)^2\)
[Reveal] Spoiler: OA
Expert Post
44 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43867
Re: A THIN PIECE OF PAPER 40 MT LONG [#permalink]

Show Tags

New post 21 Dec 2010, 07:38
44
This post received
KUDOS
Expert's post
53
This post was
BOOKMARKED
A thin piece of wire 40 meters long is cut into two pieces. One piece is used to form a circle with radius r, and the other is used to form a square. No wire is left over. Which of the following represents the total area, in square meters, of the circular and the square regions in terms of r?

A. \(\pi*r^2\)
B. \(\pi*r^2 + 10\)
C. \(\pi*r^2 + \frac{1}{4}*\pi^2*r^2\)
D. \(\pi*r^2 + (40 - 2\pi*r)^2\)
E. \(\pi*r^2 + (10 - \frac{1}{2}\pi*r)^2\)

The area of a circle will be - \(\pi{r^2}\) and \(2\pi{r}\) meters of wire will be used;
There will be \(40-2\pi{r}\) meters of wire left for a square. Side of this square will be \(\frac{40-2\pi{r}}{4}=10-\frac{\pi{r}}{2}\), hence the area of the square will be \((10-\frac{\pi{r}}{2})^2\).

The total area will be - \(\pi{r^2}+(10-\frac{\pi{r}}{2})^2\).

Answer: E.
_________________

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

Senior Manager
Senior Manager
avatar
Joined: 28 Aug 2010
Posts: 257
Re: A THIN PIECE OF PAPER 40 MT LONG [#permalink]

Show Tags

New post 23 Jan 2011, 15:04
Bunuel...how did u get side of the square as (40-2pi*r)/4 ?
_________________

Verbal:new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html
-------------------------------------------------------------------------------------------------
Ajit

Expert Post
1 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43867
Re: A THIN PIECE OF PAPER 40 MT LONG [#permalink]

Show Tags

New post 23 Jan 2011, 15:08
1
This post received
KUDOS
Expert's post
ajit257 wrote:
Bunuel...how did u get side of the square as (40-2pi*r)/4 ?


\(40-2\pi{r}\) meters of wire are left for the square means that \(40-2\pi{r}\) is the perimeter of the square so the side of it will be \(\frac{40-2\pi{r}}{4}=10-\frac{\pi{r}}{2}\).
_________________

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

1 KUDOS received
Intern
Intern
avatar
Joined: 14 Sep 2010
Posts: 20
wire [#permalink]

Show Tags

New post 16 Jan 2012, 01:21
1
This post received
KUDOS
1
This post was
BOOKMARKED
A thin piece of 40 m wire is cut in two. One piece is a circle with radius of r. Other is a square. No wire is left over. Which represents total area of circle and square in terms of r? 

From a 40m rope, two equal parts of 20 represent, respectively, the circumference of Circle C and the perimeter of Square D.

1. Express the perimeter of D in terms of the circumference of C.

Perimeter + Circumference  = 40

Perimeter = 40 - C

2. Substitute accepted identities for perimeter and circumference.

 4s = 40 - 2(pi)(r)

3.  Express the side of the square in terms of r.

s = 10 - (pi)(r)/2

4. Write area of circle and square in terms of r.

Area(C) + Area(D) 
= (pi)(r)^2 + s^2 
= (pi)(r)^2 +  (10 - (pi)(r)/2)^2

5.  Verify

2(pi)(r) = 20

r = 10/pi 
   = 3.18 (approx. to hundredth)

s   = (10 - (pi)(r)/2) 
    = 10-  [3.14(3.18)]/2
    = 5

The actual value of the side of the square derived from stating area of square in terms of r is consistent with its known perimeter.

Posted from my mobile device
Expert Post
3 KUDOS received
Veritas Prep GMAT Instructor
User avatar
G
Joined: 16 Oct 2010
Posts: 7951
Location: Pune, India
Re: 40 meters wire problem [#permalink]

Show Tags

New post 16 Jan 2012, 01:52
3
This post received
KUDOS
Expert's post
PhilosophusRex wrote:
A thin piece of wire 40 meters long is cut into two pieces. One piece is used to form a circle with radius R, and the other is used to form a square. No wire is left over. Which of the following represents the total area, in square meters, of the circular and square regions in terms of R.

1) \(\pi R^2\)
2) \(\pi R^2 + 10\)
3) \(\pi R^2 + 1/4\pi^2R^2\)
4) \(\pi R^2 + (40 - 2\pi R)^2\)
5) \(\pi R^2 + (10 - 1/2\pi R)^2\)

4) or 5) is a given, I just dont see how you make the calculation necessary.


Very minimal calculations are required if you assume a convenient value for R e.g. R = 7/2 since \(\pi = 22/7\)
Circumference in this case \(= 2\pi*R = 2*(22/7)*(7/2) = 22\)
So length of leftover wire = 18
Side of square = 18/4
Area of square = \((9/2)^2\)

Now put R = 7/2 in the second half of the options you want to check.
i.e. say you want to check option (E)
\((10 - 1/2\pi R)^2 = [10 - (1/2)*(22/7)*(7/2)]^2 = (9/2)^2\)

Option (E) is correct since the area of the square is (9/2)^2 when R = 7/2 (as shown above)
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199

Veritas Prep Reviews

Manager
Manager
avatar
Status: And the Prep starts again...
Joined: 03 Aug 2010
Posts: 136
wire [#permalink]

Show Tags

New post 05 Mar 2012, 07:38
Tried to solve this using the numbers given but I am not able to proceed. Please help. Just curious to know. Thanks.

Say the length of each piece = 20.

So Circumference =20
perimeter of square = 4*side
So length of side = 20/4 = 5.

How do I proceed further?
_________________

My First Blog on my GMAT Journey

Arise, Awake and Stop not till the goal is reached

Expert Post
2 KUDOS received
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43867
Re: wire [#permalink]

Show Tags

New post 05 Mar 2012, 07:53
2
This post received
KUDOS
Expert's post
2
This post was
BOOKMARKED
ENAFEX wrote:
Tried to solve this using the numbers given but I am not able to proceed. Please help. Just curious to know. Thanks.

Say the length of each piece = 20.

So Circumference =20
perimeter of square = 4*side
So length of side = 20/4 = 5.

How do I proceed further?


The length of each piece = 20;

Circumference of the circle is \(2\pi{r}=20\) --> \(r=\frac{10}{\pi}\) --> \(area=\pi{r^2}=\frac{100}{\pi}\);
Perimeter of the square \(4*side=20\) --> \(side=5\) --> \(area=5^2=25\);

The total area is \(\frac{100}{\pi}+25\). Now, you should substitute the value of \(r=\frac{10}{\pi}\) in the answer choices and see which one gives \(\frac{100}{\pi}+25\). Answer choice E works.

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

Manager
Manager
avatar
Joined: 07 May 2013
Posts: 104
Re: A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 01 Dec 2013, 20:52
Let the perimeter of circle be x---->2pi*r=x----(1)
Let the perimeter of square be 40-x---->4S=40-x
Substitute value of x from(1)
----->S=(40/4)-(2pi*r/4)
----->S=10-pi*r/2
----->\(S^2=(10-pi*r/2)^2\)
Therefore total area is \(pi*r^2+(10-pi*r/2)^2\)
Intern
Intern
avatar
Joined: 13 Aug 2012
Posts: 3
Re: A THIN PIECE OF PAPER 40 MT LONG [#permalink]

Show Tags

New post 24 Dec 2013, 23:35
Bunuel wrote:
A thin piece of wire 40 meters long is cut into two pieces. One piece is used to form a circle with radius r, and the other is used to form a square. No wire is left over. Which of the following represents the total area, in square meters, of the circular and the square regions in terms of r?

A. \(\pi*r^2\)
B. \(\pi*r^2 + 10\)
C. \(\pi*r^2 + \frac{1}{4}*\pi^2*r^2\)
D. \(\pi*r^2 + (40 - 2\pi*r)^2\)
E. \(\pi*r^2 + (10 - \frac{1}{2}\pi*r)^2\)

The area of a circle will be - \(\pi{r^2}\) and \(2\pi{r}\) meters of wire will be used;
There will be \(40-2\pi{r}\) meters of wire left for a square. Side of this square will be \(\frac{40-2\pi{r}}{4}=10-\frac{\pi{r}}{2}\), hence the area of the square will be \((10-\frac{\pi{r}}{2})^2\).

The total area will be - \(\pi{r^2}+(10-\frac{\pi{r}}{2})^2\).

Answer: E.



Bunuel- the perimeter of the circle and the square are the same, so: 2(pi)r=4a (a being one side of the square).
a= (pi)r/2
area of square in terms of r: a^2= (pi)^2*r^2/4
wont this mean that option c is also correct? what am I missing?
1 KUDOS received
Verbal Forum Moderator
User avatar
Joined: 15 Jun 2012
Posts: 1124
Location: United States
Premium Member
Re: A THIN PIECE OF PAPER 40 MT LONG [#permalink]

Show Tags

New post 25 Dec 2013, 01:52
1
This post received
KUDOS
gmarchanda wrote:
Bunuel wrote:
A thin piece of wire 40 meters long is cut into two pieces. One piece is used to form a circle with radius r, and the other is used to form a square. No wire is left over. Which of the following represents the total area, in square meters, of the circular and the square regions in terms of r?

A. \(\pi*r^2\)
B. \(\pi*r^2 + 10\)
C. \(\pi*r^2 + \frac{1}{4}*\pi^2*r^2\)
D. \(\pi*r^2 + (40 - 2\pi*r)^2\)
E. \(\pi*r^2 + (10 - \frac{1}{2}\pi*r)^2\)

The area of a circle will be - \(\pi{r^2}\) and \(2\pi{r}\) meters of wire will be used;
There will be \(40-2\pi{r}\) meters of wire left for a square. Side of this square will be \(\frac{40-2\pi{r}}{4}=10-\frac{\pi{r}}{2}\), hence the area of the square will be \((10-\frac{\pi{r}}{2})^2\).

The total area will be - \(\pi{r^2}+(10-\frac{\pi{r}}{2})^2\).

Answer: E.



Bunuel- the perimeter of the circle and the square are the same, so: 2(pi)r=4a (a being one side of the square).
a= (pi)r/2
area of square in terms of r: a^2= (pi)^2*r^2/4
wont this mean that option c is also correct? what am I missing?


Hello.

The question only says: A thin piece of wire 40 meters long is cut into two pieces, NOT into same length pieces. Thus, your assumption 2(pi)r=4a is wrong.

Hope it's clear.
_________________

Please +1 KUDO if my post helps. Thank you.

"Designing cars consumes you; it has a hold on your spirit which is incredibly powerful. It's not something you can do part time, you have do it with all your heart and soul or you're going to get it wrong."

Chris Bangle - Former BMW Chief of Design.

1 KUDOS received
Intern
Intern
User avatar
Joined: 04 Nov 2013
Posts: 19
Location: United States
GPA: 3.96
WE: Information Technology (Computer Software)
Re: A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 01 Jun 2014, 22:44
1
This post received
KUDOS
A little confusion here:
As the total length is 2πr + 4x = 40
=> πr + 2x = 20

I assumed length 10 as the circumference of the circle and 10 as the perimeter of the square.

=> πr=10 and x=5 and computed the total area, which is
πr²+x²
=> 100/π + 25 ----------(1)

I then substituted this values in the answer choice to find out the matches with (1), choices C and E seem to match. Can someone please tell me what am I doing wrong.

Thanks,
a
Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 43867
Re: A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 02 Jun 2014, 00:17
mamboe wrote:
A little confusion here:
As the total length is 2πr + 4x = 40
=> πr + 2x = 20

I assumed length 10 as the circumference of the circle and 10 as the perimeter of the square.

=> πr=10 and x=5 and computed the total area, which is
πr²+x²
=> 100/π + 25 ----------(1)

I then substituted this values in the answer choice to find out the matches with (1), choices C and E seem to match. Can someone please tell me what am I doing wrong.

Thanks,
a


Why did you assume that? We are NOT told that the piece is cut into the same length pieces. We are just told that the piece is cut into two pieces.
_________________

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

3 KUDOS received
SVP
SVP
User avatar
Status: The Best Or Nothing
Joined: 27 Dec 2012
Posts: 1839
Location: India
Concentration: General Management, Technology
WE: Information Technology (Computer Software)
Re: A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 10 Nov 2014, 20:41
3
This post received
KUDOS
In this problem, its not at all mentioned that "wire 40 meters long is cut into two equal pieces"

We have to take a variable for distribution of 40 meters in square & circle.

Refer diagram below:

Attachment:
sqa.png
sqa.png [ 3.51 KiB | Viewed 14654 times ]


Let the perimeter of the square = d

then circumference of the circle = 40-d

\(2\pi r = 40-d\)

\(d = 40 - 2\pi r\) ..................... (1)

Area of Circle \(= \pi r^2\) .............. (2)

Each side of square \(= \frac{d}{4} = \frac{40 - 2\pi r}{4} = 10 - \frac{\pi r}{2}\) .................... From (1)

Area of square \(= (10 - \frac{\pi r}{2})^2\)

Total Area \(= \pi r^2 + (10 - \frac{\pi r}{2})^2\)

Answer = E
_________________

Kindly press "+1 Kudos" to appreciate :)

Expert Post
3 KUDOS received
SVP
SVP
User avatar
P
Joined: 11 Sep 2015
Posts: 2058
Location: Canada
Re: A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 15 Nov 2015, 21:00
3
This post received
KUDOS
Expert's post
Quote:
A thin piece of 40 meters long is cut into two pieces. One piece is used to form a circle with radius r, and the other is used to form a square. No wire is left over. Which of the following represents the total area, in square meters, of the circular and the square regions in term of r?

A) πr²
B) πr² + 10
C) πr² + 1/4(π² * r²)
D) πr² + (40 - 2π * r)²
E) πr² + (10 - 1/2π * r)²


Another approach is to plug in a value for r and see what the output should be.

Let's say r = 0. That is, the radius of the circle = 0
This means, we use the ENTIRE 40-meter length of wire to create the square.
So, the 4 sides of this square will have length 10, which means the area = 100

So, when r = 0, the total area = 100

We'll now plug r = 0 into the 5 answer choices and see which one yields an output of 100

A) π(0²) = 0 NOPE
B) π(0²) + 10 = 10 NOPE
C) π(0²) + 1/4(π² * 0²) = 0 NOPE
D) π(0²) + (40 - 2π0)² = 1600 NOPE
E) π(0²) + (10 - 1/2π(0))² = 100 PERFECT!

Answer: E

Cheers,
Brent
_________________

Brent Hanneson – Founder of gmatprepnow.com

Image

Expert Post
Senior Manager
Senior Manager
User avatar
Joined: 20 Aug 2015
Posts: 394
Location: India
GMAT 1: 760 Q50 V44
A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 16 Nov 2015, 00:27
anilnandyala wrote:
A thin piece of wire 40 meters long is cut into two pieces. One piece is used to form a circle with radius r, and the other is used to form a square. No wire is left over. Which of the following represents the total area, in square meters, of the circular and the square regions in terms of r?

A. \(\pi*r^2\)
B. \(\pi*r^2 + 10\)
C. \(\pi*r^2 + \frac{1}{4}*\pi^2*r^2\)
D. \(\pi*r^2 + (40 - 2\pi*r)^2\)
E. \(\pi*r^2 + (10 - \frac{1}{2}\pi*r)^2\)


Given: 40 meters long wire is cut into two pieces. One circle with radius r and the rest is used to form a square
Required: Total area of the circle and the square

Since we are given the length of the wire, we should find the perimeters.

Perimeter of the circle = \(2*\pi*r\)
Hence left over wire after removing the circle = \(40 - (2*\pi*r)\)

We need to form a square from this length.
In other words, this is the perimeter of the square and each side of a square is equal.

Hence side of square = \(\frac{1}{4}(40 - (2*\pi*r))\) = \(10 - \frac{1}{2}\pi*r\)

Area of the square = \((10 - \frac{1}{2}\pi*r)^2\)

Total required area = \(\pi*r^2 + (10 - \frac{1}{2}\pi*r)^2\)
Option E
Manager
Manager
User avatar
Joined: 05 Jul 2015
Posts: 107
Concentration: Real Estate, International Business
GMAT 1: 600 Q33 V40
GPA: 3.3
A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 25 Nov 2015, 20:08
It doesn't say HOW LONG the wire is cut sooooooo

R=0 Perimeter of the Square = 40

Area of the square = 10^2

BAM!!!! Answer E.

Still took me 2 minutes just to understand the question though. :-(


Oh wow, gmatprep had the same idea as me.
Expert Post
Senior Manager
Senior Manager
User avatar
Joined: 20 Aug 2015
Posts: 394
Location: India
GMAT 1: 760 Q50 V44
Re: A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 26 Nov 2015, 01:02
DJ1986 wrote:
It doesn't say HOW LONG the wire is cut sooooooo

R=0 Perimeter of the Square = 40

Area of the square = 10^2

BAM!!!! Answer E.

Still took me 2 minutes just to understand the question though. :-(


Oh wow, gmatprep had the same idea as me.


Hi DJ1986,
Quiet an interesting way to tackle the question :)
But if we go by what you say, there is no circle at all.

Whereas the question says "One piece is used to form a circle with radius r, and the other is used to form a square"
Manager
Manager
User avatar
Joined: 05 Jul 2015
Posts: 107
Concentration: Real Estate, International Business
GMAT 1: 600 Q33 V40
GPA: 3.3
Re: A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 27 Nov 2015, 12:07
TeamGMATIFY wrote:
DJ1986 wrote:
It doesn't say HOW LONG the wire is cut sooooooo

R=0 Perimeter of the Square = 40

Area of the square = 10^2

BAM!!!! Answer E.

Still took me 2 minutes just to understand the question though. :-(


Oh wow, gmatprep had the same idea as me.


Hi DJ1986,
Quiet an interesting way to tackle the question :)
But if we go by what you say, there is no circle at all.

Whereas the question says "One piece is used to form a circle with radius r, and the other is used to form a square"


I thought about that and decided that maybe the circle is microscopically so small it may as well be rounded to zero or maybe the person just imagined cutting a wire and making a circle but never actually did. Either way 0+whatever=whatever
Manager
Manager
avatar
S
Joined: 03 Jan 2017
Posts: 193
Re: A thin piece of wire 40 meters long is cut into two pieces. [#permalink]

Show Tags

New post 28 Mar 2017, 13:00
let's take a brief look, the whole wire was used, so we need to take into account perimetr of the both figures when calculating the area
r is given, radius

Pr^2+((40-2Pr)/4)^2
We need to divide the latter by 4 because perimeter of a squae has 4 sides

Answer is E
Re: A thin piece of wire 40 meters long is cut into two pieces.   [#permalink] 28 Mar 2017, 13:00

Go to page    1   2    Next  [ 29 posts ] 

Display posts from previous: Sort by

A thin piece of wire 40 meters long is cut into two pieces.

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


GMAT Club MBA Forum Home| About| Terms and Conditions| 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®.