The radius of a sphere is $2r$,then its volume will be

Two solid spheres made of the same metal have weights $5920 \, g$ and $740 \, g$ respectively. Determine the radius of the larger sphere,if the diameter of the smaller one is $5 \, cm$. (in $cm$)

There are two boxes of metal sheet. The length,width,and height of a cuboidal box are $30 \, cm$,$25 \, cm$,and $20 \, cm$ respectively. $A$ cubical box has each edge of $25 \, cm$. Find out which box requires more metal sheet and by how many $cm^2$?

$A$ sphere and a right circular cylinder of the same radius have equal volumes. By what percentage does the diameter of the cylinder exceed its height?

$1 \, m^3 = \dots \dots$ litre

The curved surface area of a cylinder is $3960 \, cm^{2}$ and its volume is $41580 \, cm^{3}$. Find the radius and height of the cylinder.