Results 1 to 2 of 2

Math Help - Help Please!

  1. #1
    Newbie
    Joined
    Feb 2006
    Posts
    4

    Help Please!

    PLEASE tell me if I am way off. The answer I got for this one is 3.5 ft.

    A parking lot measures 100 by 130 feet. A sidewalk of uniform width is to completely surround the lot. If the sidewalk covers 1659 sq ft. how wide can the sidewalk be?


    Thanks!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor Quick's Avatar
    Joined
    May 2006
    From
    New England
    Posts
    1,024
    Quote Originally Posted by sallyann View Post
    PLEASE tell me if I am way off. The answer I got for this one is 3.5 ft.

    A parking lot measures 100 by 130 feet. A sidewalk of uniform width is to completely surround the lot. If the sidewalk covers 1659 sq ft. how wide can the sidewalk be?


    Thanks!
    you have rectangle 100x130

    the sidewalk plus the parking lot equals: (100+2s)x(130+2s)

    the area is therefore: (100+2s)x(130+2s)=13000+260s+200s+4s^2=4s^2+460s+1 3000

    now subtract the original rectangle area (100x130=13000) from the sidewalk+parking lot area to get: 4s^2+460s

    that expression gives the area of the sidewalk for width "s"

    now solve for: 4s^2+460s=1659

    which comes out to: s=3.5

    so you got it right
    Last edited by Quick; September 24th 2006 at 07:15 PM.
    Follow Math Help Forum on Facebook and Google+


/mathhelpforum @mathhelpforum