Solve the Problem, If Possible $12 \mathrm{ft}$ By $15 \mathrm{ft}$ And the Area of the Rug Is

Solve the problem, if possible. Round your answer to the nearest tenth, when appropriate.
-A rug is to fit in a room so that a border of even width is left on all four sides. If the room is $12 \mathrm{ft}$ by $15 \mathrm{ft}$ and the area of the rug is $108 \mathrm{ft}^{2}$ , how wide will the border be?

A) $1.5 \mathrm{ft}$
B) $2 \mathrm{ft}$
C) $3.5 \mathrm{ft}$
D) $2.5 \mathrm{ft}$