........ litres of water at the most can be stored in a cubical tank with length $1\, m$.

Write 'True' or 'False' and justify your answer:
The volume of the frustum of a cone is $\frac{1}{3} \pi h[r_{1}^{2} + r_{2}^{2}-r_{1} r_{2}],$ where $h$ is the vertical height of the frustum and $r_{1}, r_{2}$ are the radii of the ends.

The $TSA$ (Total Surface Area) of a hemisphere with a diameter of $10 \, cm$ is $\ldots \ldots \ldots \, cm^2$. (in $\pi$)

Total surface area of a cylinder $= \dots$

The volume of a cone with radius $5 \, cm$ and height $12 \, cm$ is ........ $\pi \, cm^{3}$.

The radii of two $10 \, cm$ high metallic cylinders are $3.5 \, cm$ and $7 \, cm$. These cylinders are melted and recast to produce a cylinder with height $50 \, cm$. Find the radius of this new cylinder (in $cm$).