In the middle of a rectangular room, is a rectangular rug, 13 feet by 15 feet. A strip of hardware floor of uniform width is visible around the rug. If the area of the strip is 60 square feet, how wide (in feet) is the strip
Let uniform width of hardwood floor, be W
Since shorter side of rug is 13 feet, shorter side of entire room = 13 + 2W
Since longer side of rug is 15 feet, longer side of entire room = 15 + 2W
Since area of entire room, equals area of rug, plus area of hardwood floor, it can be said that:
{13 + 2W)(15 + 2W) = 60 + 15(13)
(W - 1)(W + 15) = 0
W, or width of strip = foot OR W = - 15 (ignore)