If a marble of radius $2.1 \, cm$ is put into a cylindrical cup full of water of radius $5 \, cm$ and height $6 \, cm$,then how much water flows out of the cylindrical cup? (in $cm^3$)

$A$ building is in the form of a cylinder surmounted by a hemispherical dome (see figure). The base diameter of the dome is equal to $\frac{2}{3}$ of the total height of the building. Find the height of the building,if it contains $67 \frac{1}{21} \, m^3$ of air. (in $m$)

The volume of a sphere with radius $1.5\,cm$ is $\ldots \ldots \ldots \ldots cm^{3}$. (in $\pi$)

The volume of a hemisphere is equal to:

The radius and height of a cone are both $3 \, cm$. Then,its volume is $\ldots \ldots \ldots \, cm^{3}$. (in $\pi$)

$A$ bucket is in the form of a frustum of a cone of height $30 \,cm$ with radii of its lower and upper ends as $10 \,cm$ and $20 \,cm$,respectively. Find the capacity and surface area of the bucket. Also,find the cost of milk which can completely fill the container,at the rate of $Rs. \, 25$ per $litre$ (use $\pi = 3.14$).