The radii of a cylinder and a cone are equal. If the height of the cylinder is equal to the slant height of the cone,then the ratio of the curved surface areas of the cylinder and the cone is: (in $:1$)

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 $\pi = \frac{22}{7}$)

$A$ cylindrical vessel of radius $4 \, cm$ contains water. $A$ solid sphere of radius $3 \, cm$ is lowered into the water until it is completely immersed. The water level in the vessel will rise by (in $cm$)

From a solid right circular cylinder with height $10 \ cm$ and radius of the base $6 \ cm$,a right circular cone of the same height and base is removed. The volume (in $cm^3$) of the remaining solid is

If $h, c, v$ are respectively the height,curved surface area,and volume of a right circular cone,then the value of $3 \pi v h^{3} - c^{2} h^{2} + 9 v^{2}$ is

$A$ rectangular water tank is $80 \, m \times 40 \, m$. Water flows into it through a pipe with an opening area of $40 \, cm^2$ at a speed of $10 \, km/h$. By how much will the water level in the tank rise in half an hour (in $cm$)?