$A$ cylindrical tank with radius $8.4 \,cm$ is closed at one end by a hemisphere. If the total height of the tank is $52.8 \,cm$,how many litres of petrol can it contain (in $.088$)? (in $litres$)

The $CSA$ (Curved Surface Area) of a hemisphere is equal to $\ldots \ldots \ldots$

Total surface area of a closed cube with length $4 \, cm$ is $\ldots \ldots \ldots cm^{2}$.

$A$ hollow cube of internal edge $22 \, cm$ is filled with spherical marbles of diameter $0.5 \, cm$. It is assumed that $\frac{1}{8}$ of the space of the cube remains unfilled. The number of marbles that the cube can accommodate is:

$A$ toy is in the form of a cone surmounted on a hemisphere. The radius of the cone as well as the hemisphere is $3.5\, cm$ and the total height of the toy is $15.5\, cm$. Find its total surface area (in $cm^2$).

Curved surface area of a cone = ....................