$A$ well,$20 \, m$ deep,is $7 \, m$ in radius. Find the cost of cementing the inner curved surface at the rate of ₹ $15$ per $m^2$. (in ₹)

$A$ cuboidal water tank is $2\, m$ long,$1\, m$ wide,and $80\, cm$ deep (height). Its remaining five surfaces,excluding the base,are covered with square tiles of size $20\, cm \times 20\, cm$. Find the number of tiles required.

The areas of the three surfaces meeting at one vertex of a cuboid are $700 \, cm^2$,$300 \, cm^2$,and $525 \, cm^2$ respectively. Find the dimensions and volume of the cuboid.

State whether the following statement is true or false:
The lateral surface area of a cube with an edge length of $5 \, cm$ is $150 \, cm^2$.

Find the curved surface area and the total surface area of a hemisphere with a radius of $14\, cm$.

The radius and volume of a cylinder are $3.5\,cm$ and $2310\,cm^3$ respectively. Find its height in $cm$.