Mathematics · Mensuration

The original layout of a rectangular plot ABCD on open ground is 80 m long along AB, and 60 m wide along BC. Concreted pathways are to be laid on the inside of the plot along all sides. The pathways along BC and DA are each 4 m wide. The pathways along AB and DC are of equal width, such that the un-concreted internal plot area measures three-fourths of the original area of plot ABCD. What is the width of each of the pathways along AB and DC?