$A$ juice seller was serving his customers using glasses as shown in the figure. The inner diameter of the cylindrical glass was $5 \, cm$,but the bottom of the glass had a hemispherical raised portion which reduced the capacity of the glass. If the height of a glass was $10 \, cm$,find the apparent capacity of the glass and its actual capacity (in $cm^3$). (Use $\pi = 3.14$)

$A$ cone of height $24\, cm$ and radius of base $6\, cm$ is made up of modelling clay. $A$ child reshapes it in the form of a sphere. Find the radius of the sphere (in $cm$).

An open metal bucket is in the shape of a frustum of a cone,mounted on a hollow cylindrical base made of the same metallic sheet (see figure). The diameters of the two circular ends of the bucket are $45 \, cm$ and $25 \, cm$,the total vertical height of the bucket is $40 \, cm$ and that of the cylindrical base is $6 \, cm$. Find the area of the metallic sheet used to make the bucket,where we do not take into account the handle of the bucket. Also,find the volume of water the bucket can hold. (Take $\pi = \frac{22}{7}$)

Derive the formula for the volume of the frustum of a cone.

In one fortnight of a given month,there was a rainfall of $10 \, cm$ in a river valley. If the area of the valley is $7280 \, km^2$,show that the total rainfall was approximately equivalent to the addition to the normal water of three rivers each $1072 \, km$ long,$75 \, m$ wide,and $3 \, m$ deep.

Derive the formula for the curved surface area and total surface area of the frustum of a cone.