Total surface area of a cuboid measuring $15\,cm \times 12\,cm \times 10\,cm$ is $\ldots \ldots \ldots \,cm^{2}$.

The total surface area of a cone is equal to $\ldots \ldots \ldots \ldots .$

Write 'True' or 'False' and justify your answer:
Two identical solid hemispheres of equal base radius $r \text{ cm}$ are joined together along their bases. The total surface area of the resulting solid is $6 \pi r^{2}$.

The $TSA$ (Total Surface Area) of a hemisphere is equal to $\ldots \ldots \ldots$

$A$ container,opened from the top and made up of a metal sheet,is in the form of a frustum of a cone of height $16 \, cm$ with radii of its lower and upper ends as $8 \, cm$ and $20 \, cm$,respectively. Find the cost of the milk which can completely fill the container,at the rate of $Rs. \, 20$ per litre. Also,find the cost of the metal sheet used to make the container,if it costs $Rs. \, 8$ per $100 \, cm^2$. (Take $\pi = 3.14$)

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