Find the curved surface area of a right circular cone whose slant height is $10\, cm$ and base radius is $7\, cm$. (in $, cm^{2}$)

$A$ village,having a population of $4000$,requires $150$ litres of water per head per day. It has a tank measuring $20 \,m \times 15 \,m \times 6 \,m$. For how many days will the water of this tank last?

It costs $Rs. 2200$ to paint the inner curved surface of a cylindrical vessel $10\, m$ deep. If the cost of painting is at the rate of $Rs. 20$ per $m^2$,find the capacity of the vessel. (in $, kl$)

Monica has a piece of canvas whose area is $551 \, m^2$. She uses it to have a conical tent made,with a base radius of $7 \, m$. Assuming that all the stitching margins and the wastage incurred while cutting amounts to approximately $1 \, m^2$,find the volume of the tent that can be made with it. (in $, m^3$)

The height of a cone is $16 \, cm$ and its base radius is $12 \, cm$. Find the curved surface area and the total surface area of the cone (Use $\pi = 3.14$). (in $, cm^2$)

$A$ lead pencil consists of a cylinder of wood with a solid cylinder of graphite filled in the interior. The diameter of the pencil is $7 \,mm$ and the diameter of the graphite is $1 \,mm$. If the length of the pencil is $14 \,cm$,find the volume of the wood and that of the graphite. (in $,cm^3$)