If the wallpaper is sold in rolls that are 2 feet wide, then the width is 2 feet, to get the length, substitute W = 2 and P = 60 into the formula for calculating the perimeter of a rectangle.
60 = 2L + 2(2)
60 = 2L + 4
2L = 60-4
2L = 56
L = 56/2
L = 28
<em>The minimum length that will be purchased to cover the wall is 28 feet</em>