Answer: [tex]249.48\ m^2; 369.168\ m^3[/tex]
Step-by-step explanation:
Given
Cost of white-washing =Rs. 4989.60
Rate =20 per meter square
So, inside area of = [tex]\dfrac{4989.60}{20}=249.48\ m^2[/tex]
The surface area of dome= [tex]4\pi\ r^2=249.48[/tex]
[tex]4\times 3.142\times r^2=249.48\\r^2=\frac{249.48}{4\times 3.142}=19.85\\r=4.455\ m[/tex]
The volume of air in the dome [tex]V=\frac{4}{3}\pi r^3[/tex]
[tex]V=\frac{4}{3}\cdot 3.142\cdot (4.45)^3\\V=369.17\ m^3[/tex]
