Problem Solving

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
Answer is E

[spoiler]Area of table = X = 3 x Length
Length of strip = X = Perimeter of table
i.e. 6 +2Length = X

From the first 3xLength = 6 +2Length
i.e. 3L = 6+2L
or L = 6[/spoiler]