7. Find the cost of painting

The monument is in the form of a hemisphere mounted on the cuboid. The hemisphere is of radius 21 \(m\) and, the cuboid is of dimension \(28 m \times 25 m \times 30 m\). If the cost of painting the monument is \(₹18\) per metre square, find the total cost of painting the monument?

 

Answer:

 

The total cost of painting the monument \(=\) \(₹\) .

 

[Note: Use \(\pi = \frac{22}{7}\).]