Path Width Around a Rectangular Plot

A farmer has a rectangular plot of land which is 20 meters long and 15 meters wide. He wants to build a path of uniform width around the plot. If he wants the total area covered by the plot and the path to be 500 square meters, what will be the width of the path?

To find the area of the larger rectangle (plot plus path), calculate:

$$ A = (l + 2w)(w + 2h) $$

where $A$ is the total area, $l$ is length, $h$ is width, and $w$ is the width of the path.