The radius of the base of a cylinder is $7 \, cm$. Then,the area of its base is $\dots \, cm^2$.

Two solid cones $A$ and $B$ are placed in a cylindrical tube as shown in the figure. The ratio of their capacities is $2:1$. Find the heights and capacities of the cones. Also,find the volume of the remaining portion of the cylinder (in $cm^{3}$).

$A$ 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 curved surface area $(CSA)$ of a cone is $\ldots \ldots$

The radius of a sphere with surface area $1256\,cm^{2}$ is $\ldots \ldots \ldots cm$. $(\pi = 3.14)$

Marbles of diameter $1.4 \,cm$ are dropped into a cylindrical beaker of diameter $7 \,cm$ containing some water. Find the number of marbles that should be dropped into the beaker so that the water level rises by $5.6 \,cm$.