First, the surface area of each oil drum:

The area of a cardinal number: (0.4 ÷ 2) × (0.4 ÷ 2 )× 3.14 = 0.1256.

Side area: 2× 3.14× 0.4× 0.6 =1.5072.

The area of oil drum to be brushed is

0.1256× 2+1.5072 =1.7584 (m2)

100 What is the weight of pigment needed for the brush?

1.7584×100× 0.6 =105.504 (kg).