Total area: 3.14 * 40 * 40 *100 = 502,400 square centimeters =50.24 square meters.
Paint: 50.24 * 0.6 = 30. 144kg.
Comprises the bottom of a barrel;
Radius: 40/2 = 20cm
Total area: (3.14 * 40 * 40+3.14 * 20 * 20) *100 = 628,000 square centimeters =62.8 square meters.
Paint: 62.8 * 0.6 = 37.68kg