Question

A hemisphere dome of a building is to be white washed and the total cost of white wash of dome building is ₹924 at the rate of ₹3per m²,then find(i) The surface area of hemisphere (ii) volume of air in the dome

Answer 1

Given,
Cost of white washing the dome=₹924
Rate of white washing the dome=₹3per m²
=>Surface area of turn dome =924/3
=308 m²
=>2×π×r² =308 m²
=>2×22/7×r² =308 m²
=>r² =308×7/22
=>r² =49
=>r =7
Now Volume of the dome =2/3πr³
=2/3×22/7×7×7
×7
=2156/3