Last visit was: 21 Jul 2024, 21:20 It is currently 21 Jul 2024, 21:20
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
SORT BY:
Date
Tags:
Show Tags
Hide Tags
avatar
Intern
Intern
Joined: 28 May 2013
Posts: 2
Own Kudos [?]: 253 [83]
Given Kudos: 2
Location: United States
Concentration: Marketing, Healthcare
WE:Military Officer (Military & Defense)
Send PM
Most Helpful Reply
MBA Section Director
Joined: 22 Feb 2012
Affiliations: GMAT Club
Posts: 8767
Own Kudos [?]: 10206 [19]
Given Kudos: 4553
Test: Test
Send PM
GMAT Club Legend
GMAT Club Legend
Joined: 19 Dec 2014
Status:GMAT Assassin/Co-Founder
Affiliations: EMPOWERgmat
Posts: 21835
Own Kudos [?]: 11790 [10]
Given Kudos: 450
Location: United States (CA)
GMAT 1: 800 Q51 V49
GRE 1: Q170 V170
Send PM
General Discussion
avatar
Intern
Intern
Joined: 17 Dec 2014
Posts: 10
Own Kudos [?]: 5 [0]
Given Kudos: 0
Send PM
Re: The length of a rectangular floor is twice its width. The [#permalink]
Ah nice this is much quicker than my method. I did it like this:

L=2w area = L*w

area is here 160 = L*w but because the carpet is 2 feet less w = w-2
160=
w-2 * 2w this can be:
1 * 160 or
2 * 80 or
4 * 40 or
5 * 32 or
8 * 20 or
10 * 16

Now you see that 8 * 20 is the only option. But it takes much more time..
avatar
Intern
Intern
Joined: 17 Dec 2014
Posts: 10
Own Kudos [?]: 5 [0]
Given Kudos: 0
Send PM
Re: The length of a rectangular floor is twice its width. The [#permalink]
Ah nice this is much quicker than my method. I did it like this:

L=2w area = L*w

area is here 160 = L*w but because the carpet is 2 feet less w = w-2
160=
w-2 * 2w this can be:
1 * 160 or
2 * 80 or
4 * 40 or
5 * 32 or
8 * 20 or
10 * 16

Now you see that 8 * 20 is the only option.
avatar
Manager
Manager
Joined: 11 Feb 2015
Posts: 69
Own Kudos [?]: 120 [1]
Given Kudos: 70
GMAT 1: 710 Q48 V38
Send PM
Re: The length of a rectangular floor is twice its width. The [#permalink]
1
Kudos
Straight algebra


L=2w
L(w-2)=160
Lw -2l =160
L^2/2 -2l =160 => l^2 -4l -320=0 . so l=20 or -16. Ans :C
User avatar
Manager
Manager
Joined: 05 Jul 2015
Posts: 53
Own Kudos [?]: 190 [2]
Given Kudos: 3
Concentration: Real Estate, International Business
GMAT 1: 600 Q33 V40
GPA: 3.3
Send PM
Re: The length of a rectangular floor is twice its width. The [#permalink]
2
Kudos
I'm terrible at GMAT math so I always look for shortcuts...

Floor Area = 2w^2
Carpet Area = 160 which is slightly less than the floor.

So to guesstimate 2w^2=160..... w^2=80......w = around 9 ...
Length is a little bigger than 2*9....... 20 is closest answer.
Manager
Manager
Joined: 25 Mar 2013
Posts: 166
Own Kudos [?]: 133 [0]
Given Kudos: 101
Location: United States
Concentration: Entrepreneurship, Marketing
GPA: 3.5
Send PM
Re: The length of a rectangular floor is twice its width. The [#permalink]
Complete Rectangular floor
Width(W) = 10, Length = 2W
Carpet :
Width = W-2
same Length = 2W
A = 160 = 2W (W-2)
80 = W^2 - 2W
w^2 - 2W - 80 = 0
W = 10
Length = 2w = 20
C
Board of Directors
Joined: 11 Jun 2011
Status:QA & VA Forum Moderator
Posts: 6049
Own Kudos [?]: 4767 [0]
Given Kudos: 463
Location: India
GPA: 3.5
WE:Business Development (Commercial Banking)
Send PM
Re: The length of a rectangular floor is twice its width. The [#permalink]
Jem2905 wrote:
The length of a rectangular floor is twice its width. The floor is partially covered by a rectangular carpet whose length is the same as the lenfth of the floor and whose width is two feet less than the width of the floor. If the area of the carpet is 160 sq. feet, what is the length, in feet, of the floor?

A. 8
B. 16
C. 20
D. 24
E. 32


Floor :

Length = \(2w\)
Width = \(w\)

Area = \(2w^2\)


Carpet :

Length = \(2w\)
Width = \(w-2\)

Area = \(2w^2 - 4w\)


Quote:
If the area of the carpet is 160 sq. feet


\(2w ( w - 2 ) = 160\)

Or, \(w(w-2) = 80\)

So, \(w = 10\)

So, Length of the floor is \(2w = 20\)

Hence the length of floor is 20 , correct answer must be (C) 20
Intern
Intern
Joined: 23 Nov 2016
Posts: 8
Own Kudos [?]: 77 [8]
Given Kudos: 214
Send PM
Re: The length of a rectangular floor is twice its width. The [#permalink]
8
Kudos
Jem2905 wrote:
The length of a rectangular floor is twice its width. The floor is partially covered by a rectangular carpet whose length is the same as the lenfth of the floor and whose width is two feet less than the width of the floor. If the area of the carpet is 160 sq. feet, what is the length, in feet, of the floor?

A. 8
B. 16
C. 20
D. 24
E. 32

Got this wrong on a practice test and think I've come up with the correct answer, but cant check it since the damn software erased my test; throwing it up here on the forum, hoping someone on here can confirm or disprove what I came up with on the second shot...


There is a simpler solution-
Let Table area = l*2l --- (where l=width and 2l=length) ---- (1)
Therefore Cloth area = (l-2)*2l ------(2)
So all we need is the value of 2l .

From the given information in (2) , we get (l-2)*2l = 160
Simplifying we get (l-2)*l =80
From the above eq. we can easily workout (l-2)*l = 8*10
This give l=10 .
Now all we need is 2l= 20 .
Hence answer = C
User avatar
Non-Human User
Joined: 09 Sep 2013
Posts: 34040
Own Kudos [?]: 853 [0]
Given Kudos: 0
Send PM
Re: The length of a rectangular floor is twice its width. The [#permalink]
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.
GMAT Club Bot
Re: The length of a rectangular floor is twice its width. The [#permalink]
Moderator:
Math Expert
94441 posts