Painting a sheet of metal requires $5/m^2. It is given that half a sheet of area 50 m^2 is used to make a sphere and the rest is used to make a cube. The total cost of painting the cube and the sphere and the cube is required.
It should be noticed here that no matter what the dimensions of the cube or the sphere are, the surface area of the sheet they are made with is 50 m^2. To determine the cost of painting there is no need to determine the volume of any of their of them. Just multiplying the surface area of the sheet by the cost of painting 1 square meter gives the result. $5*50 = $250.
The cost of painting the cube and sphere on the outside is $250.