The radii of a frustum of a cone are $10 \, cm$ and $7 \, cm$. If its height is $4 \, cm$,its curved surface area is $\dots \dots \dots \pi \, cm^2$.

The curved surface area of a cone is $85 \pi \, cm^{2}$. If its diameter is $10 \, cm$,its slant height is $\dots \dots \dots \dots \, cm$.

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 $cm^{3}$).

$A$ cylinder with radius $6 \, cm$ is closed at one end by a $8 \, cm$ high cone and is open at the other end. The total height of the article is $20 \, cm$. Find the total surface area of the article. $(\pi = 3.14)$ (in $cm^2$)

$A$ cylinder is closed at both ends by hemispheres. The radius of the cylinder is $21 \, cm$ and the total height of the article is $92 \, cm$. Find the total surface area of the article (in $cm^2$).

The base of a cone with radius $7\, cm$ and height $24\, cm$ is hemispherical. Find the cost of painting its surface at the rate of ₹ $2/cm^2$. (in ₹)