The surface area and volume of a cube with an edge length of $x \ cm$ are numerically equal. Find the value of $x$.

$A$ storage tank is in the form of a cube. When it is full of water, the volume of water is $15.625 \, m^3$. If the present depth of water is $1.3 \, m$, find the volume of water already used from the tank (in $m^3$).

The radius of a hemispherical balloon increases from $6\,cm$ to $12\,cm$ as air is being pumped into it. The ratio of the surface areas of the balloon in the two cases is

Each of the radius of a cylinder and a sphere is $9 \, cm$. If the volumes of these solids are equal,find the height of a cylinder (in $cm$).

Write True or False and justify your answer in each of the following: If the radius of a right circular cone is halved and height is doubled,the volume will remain unchanged.

The curved surface area of a cylinder is $4400 \, cm^2$ and its base has a radius of $14 \, cm$. Find the volume of the cylinder in $cm^3$.