A dome of a building is in the form of a hemisphere from inside it was whitewashed at the cost of rupees 4989.60 if the cost of white washing is rupees 20 per meter square find …

Question

asked Dec 4, 2022 219k views

1 Answer

Pantsgolem · Answer 1 · 2022-12-10T16:57:52+0000

Answer:
$249.48\ m^2; 369.168\ m^3$

Explanation:

Given

Cost of white-washing =Rs. 4989.60

Rate =20 per meter square

So, inside area of =
$(4989.60)/(20)=249.48\ m^2$

The surface area of dome=
$4\pi\ r^2=249.48$

$4* 3.142* r^2=249.48\\r^2=(249.48)/(4* 3.142)=19.85\\r=4.455\ m$

The volume of air in the dome
$V=(4)/(3)\pi r^3$

$V=(4)/(3)\cdot 3.142\cdot (4.45)^3\\V=369.17\ m^3$