$A$ hollow sphere of internal and external diameters $4\,cm$ and $8\,cm$ respectively is melted into a cone of base diameter $8\,cm$. The height of the cone is......$cm$.

The height of a wall is six times its width,and the length of the wall is seven times its height. If the volume of the wall is $16128 \, m^3$,its width is ...... $m$.

$A$ cylinder and a cone have equal radii of their bases and equal heights. If their curved surface areas are in the ratio $8:5$,the ratio of their radius and height is

If a right circular cone of height $24\, cm$ has a volume of $1232\, cm^{3},$ then the area (in $cm^{2}$) of its curved surface is:

The base of a right pyramid is an equilateral triangle of side $4 \text{ cm}$. The height of the pyramid is half of its slant height. Its volume is ........ $\text{cm}^3$.

$A$ large solid sphere is melted and moulded to form identical right circular cones with base radius and height same as the radius of the sphere. One of these cones is melted and moulded to form a smaller solid sphere. Then the ratio of the surface area of the smaller to the surface area of the larger sphere is