A log of wood of dimensions $2 \mathrm{m}\times 20 \mathrm{cm}\times 10 \mathrm{cm}$is cut into small blocks of $10 \mathrm{cm} \mathrm{x} 5 \mathrm{cm} \mathrm{x} 4 \mathrm{cm}.$ How many blocks do we get? What will be the total surface area of all these blocks?

The curved surface area of a cylinder is $1,000 {\mathrm{cm}}^2$ and the radius of its base is $21 \mathrm{cm}$. Find the total surface area of the cylinder.

(Take $\pi =\frac{22}{7}$)

It costs $₹2200$ to paint the inner curved surface of a cylindrical vessel $10 \mathrm{m}$ deep. If it is painted at the rate of $₹20$per square metre, find:

the inner curved surface area of the vessel

It costs $₹2200$ to paint the inner curved surface of a cylindrical vessel $10 \mathrm{m}$ deep. If it is painted at the rate of $₹20$ per square metre, find:

the radius of the base 

A cylindrical road roller is of length $2 \mathrm{m}$ and diameter $84 \mathrm{cm}$. Find the number of revolutions it has to make to cover an area of $7,920 {\mathrm{m}}^2$.

[Take $\pi =\frac{22}{7}$]