Question

A dome of a building is in the form of a hemisphere. From inside, it was whitewashed at the cost of Rs. 498.96. If the cost of whitewashing is Rs. 2 per square meter, find the inside surface area of the dome,
$[Assume\pi =\frac{22}{7}]$

• A. $249.48m^2$
• B. $289.48m^2$
• C. $149.48m^2$
• D. $209.48m^2$

Answer 1

The correct option is A

$249.48m^2$

Cost of whitewashing the dome from inside = Rs. 498.96
Cost of white-washing $1m^2$ area = Rs. 2
Therefore, CSA of the inner side of dome $=\left(\frac{498.96}{2}\right)m^2$
$=249.48m^2$