A hemispherical dome of a building has an external radius of 10.5 m
MATHEMATICS · Subjective · CBSE · Mathematics · Surface Areas and Volumes · Surface Areas and Volumes
Problem
A hemispherical dome of a building has an external radius of 10.5 m. The management is considering two different exterior paints for the dome.
Paint A: Rs 35 per square metre and lasts for 5 years.
Paint B: Rs 50 per square metre and lasts for 8 years.
a) Determine the outside surface area of the dome to be painted.
b) Calculate the cost of one complete application of each paint.
c) On the basis of cost per year of service, decide which paint is the more economical choice. Show all working.