Question 1195301
{{{pi*r^2}}} area corresponds to 40 liters of paint.


{{{4pi*r^2}}} would be whole sphere area, but the building is hemisphere
so  {{{2pi*r^2}}} would be the area needing to be painted.


{{{(2pi*r^2)/(pi*r^2)=2}}}
Ratio of the exterior paint to the floor paint is 2;
therefore  80 liters of paint needed for the exterior.