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

Redeem

Perimeter

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 10
Joined: Mon Aug 11, 2008 11:22 am

Perimeter

by Rodrigo » Mon Apr 13, 2009 6:35 am
A rectangular tabletop consists of a piece of laminated wood bordered by a thin metal strip along its four edges. The surface area of the tabletop is x square feet, and the total length of the strip before it was attached was x feet. If the tabletop is 3 feet wide, what is its approximate length, in feet?

a) 12
b) 10
c) 9
d) 8
e) 6

OA: E
Top
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 92
Joined: Wed Mar 25, 2009 12:13 pm
Thanked: 10 times

by moutar » Mon Apr 13, 2009 6:43 am
Let a be the length of the table.

Length of strip: 3 + a + 3 + a = x
6 + 2a = x

Surface area: 3a = x

Equate the x's:

3a = 2a + 6
a = 6

Answer E
Top
Junior | Next Rank: 30 Posts
Posts: 10
Joined: Mon Aug 11, 2008 11:22 am

Perimeter

by Rodrigo » Mon Apr 13, 2009 8:49 am
Thank you very much, Moutar!
Top
Master | Next Rank: 500 Posts
Posts: 113
Joined: Thu Feb 26, 2009 8:13 am
Location: New Jersey
GMAT Score:650

Re: Perimeter

by KICKGMATASS123 » Mon Apr 13, 2009 10:54 am
why do u equate perimeter to area?

how do u know that perimeter = area of rectangle?

thanks in advance
Top
Master | Next Rank: 500 Posts
Posts: 158
Joined: Tue Sep 30, 2008 8:47 am
Thanked: 23 times
Followed by:1 members
GMAT Score:660

by DeepakR » Mon Apr 13, 2009 6:28 pm
You have a rectangular wooden piece bordered by metal strip (rectangle). From the question total length of the strip = x = Perimeter of the metal strip.

We also know that the width of the strip = 3 (i.e the width of the table top) hence x= 3+a+3+a = 6+2a where a = length of table top(metal strip).

Also given is SA of table top =x = 3*a now solving
x= 6+2a,
which implies 3a=6+2a hence a = 6 E.)

- Deepak
Top
Post new topic Post Reply
• Page 1 of 1