Answer
Given,
Mass of bag = 6 Kg
Area covered by the bag = 2.5 x 5 = 12.5 m²
a) Bags required to cover area = 7.5 x 10.2
                          = 76.5 m²
 Number of bags, N = [tex] \dfrac{76.5}{12.5}[/tex]
                N = 6.12 = 7 (approx.)
7 Bags of 6 Kg fertilizers will be needed to cover the area.
b) Cost of 6 Kg fertilizers = $15.50
 Cost of 7 bags of 6 Kg fertilizers = 7 x $15.50
                             = $108.50.
