$A$ cuboidal box measures $25 \, cm \times 15 \, cm \times 8 \, cm$. Find its total surface area (in $cm^2$).

The radius of a cone is $15 \, cm$ and its slant height is $25 \, cm$. Find the curved surface area and the total surface area of the cone. $(\pi = 3.14)$

The total surface area of a cube is $864 \, cm^2$. Then its edge is $\ldots \ldots \ldots \, cm$.

The length,breadth,and height of a hall are $7\, m$,$5\, m$,and $4\, m$ respectively. It has two doors measuring $3\, m \times 2\, m$ each and four windows measuring $2\, m \times 1\, m$ each. Find the cost of whitewashing all the four walls and the ceiling of the hall at the rate of ₹$200$ per $m^2$.

Find the volume of a sphere of radius $2.1 \, cm$. (in $cm^3$)

The radius of the base of a cone is $7 \, cm$ and its height is $30 \, cm$. Find the volume of a cone (in $cm^3$).