If the radius of a sphere is increased by $2 \, m$,its surface area is increased by $704 \, m^2$. What is the radius of the original sphere? (in $m$)
(use $\pi = \frac{22}{7}$)

$A$ hollow hemispherical bowl is made of silver with its outer radius $8\, cm$ and inner radius $4\, cm$. The bowl is melted to form a solid right circular cone of radius $8\, cm$. The height of the cone formed is......$cm$

From a cubical block of wood of side $1 \, m$,a cylinder of the largest possible volume is carved out. The volume (in $m^3$) of the remaining wood is

Find the weight of a hollow cylindrical lead pipe $28\, cm$ long and $0.5\, cm$ thick. Its internal diameter is $8\, cm$. (in $kg$) (Weight of $1\, cm^3$ of lead is $11.4\, g$,$\pi = \frac{22}{7}$)

$X$ and $Y$ are two cylinders of the same height. The base of $X$ has a diameter which is equal to half the diameter of the base of $Y$. If the height of $X$ is doubled,the volume of $X$ becomes

The material of a cone is converted into the shape of a cylinder of equal radius. If the height of the cylinder is $5\, cm$,the height of the cone is........$cm$.