How many spherical lead shots,each of diameter $4.2 \, cm$,can be obtained from a solid rectangular lead piece with dimensions $66 \, cm \times 42 \, cm \times 21 \, cm$?

$A$ medicine capsule is in the shape of a cylinder of diameter $0.5\, cm$ with two hemispheres stuck to each of its ends. The length of the entire capsule is $2\, cm$. The capacity of the capsule is (in $cm^3$):

$A$ cylindrical bucket of height $32 \,cm$ and base radius $18 \,cm$ is filled with sand. This bucket is emptied on the ground and a conical heap of sand is formed. If the height of the conical heap is $24 \,cm$,find the radius and slant height of the heap.

Write 'True' or 'False' and justify your answer:
Two identical solid cubes of side $a$ are joined end to end. Then the total surface area of the resulting cuboid is $12 a^{2}$.

Total surface area of a hemisphere with diameter $2 \, cm$ is $\ldots \ldots \ldots cm^{2}$.

How many shots,each having a diameter of $3 \, cm$,can be made from a cuboidal lead solid of dimensions $9 \, cm \times 11 \, cm \times 12 \, cm$?