It is required to paint the surface of a rectangular parallelepiped with measurements 40cm, 30cm, 20cm.

It is required to paint the surface of a rectangular parallelepiped with measurements 40cm, 30cm, 20cm. How much paint is required if a square needs 2g to paint 1 dm. paints.

First, let’s convert the units of measurement to decimeters:
40 cm = 4 dm, 30 cm = 3 dm, 20 cm = 2 dm.
We solve this problem as follows: first, we find the area of the entire surface. Since the parallelepiped is rectangular, the area of the entire surface will be equal to the sum of the areas of all its faces:
4 * 3 * 2 + 4 * 2 * 2 + 3 * 2 * 2 = 24 + 16 + 12 = 52 dm2;
Since the consumption of paint is 2 g per 1 dm2, then the total paint is necessary:
2 * 52 = 104 (g).
Answer: 104 g of paint is required to paint this rectangular parallelepiped.