$5$ cubes of sides $8 \mathrm{cm}$ are melted to form a cuboid of square base with height $10 \mathrm{cm}$. If the side of the square base of the cuboid so formed is $\mathrm{k} \mathrm{cm}$, then find $\mathrm{k}$.

A right circular cylinder has base radius $70 \mathrm{cm}$ and height $7 \mathrm{m}$. Find: Curved surface area of the cylinder (excluding units).

A right circular cylinder has base radius $70 \mathrm{cm}$ and height $7 \mathrm{m}$, if the total surface area of the cylinder is $k {\mathrm{m}}^2$ then, find the value of $k$ correct up to two decimal places. $\left[\text{Take,} \mathrm{\pi }=\frac{22}{7}\right]$