A cone is filled of water poured into the hemisphere, which is also filled. The radius and height of a cone are $10\mathrm{cm}$ and $20\mathrm{cm}$, respectively. Find the radius of the hemisphere (in $\mathrm{cm}$ ).

The water for a factory is stored in a hemispherical tank, whose internal diameter is $14 \mathrm{m}$. The tank contains $50 \mathrm{KL}$ of water. Water is pumped into the tank to fill to its capacity. If the volume of water pumped into the tank is $k {\mathrm{m}}^3$.

Then find the value of $k$ correct to two decimal places.

[Take $\mathrm{\pi }=\frac{22}{7}$]

A wooden article was made by scooping out a hemisphere from each end of a solid cylinder, as shown in the figure. If the height of the cylinder is $10 \mathrm{cm}$ and its base is of radius $3.5 \mathrm{cm}$, then if the total surface area of the article is $\mathrm{k} {\mathrm{cm}}^2$, find the value of $\mathrm{k}$.  [Take $\mathrm{\pi }=\frac{22}{7}$]