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

The radius and height of a cylinder are $10\,cm$ and $30\,cm$ respectively. Find the cost of painting its outer curved surface at the rate of ₹ $3$ per $cm^2$. (Use $\pi = 3.14$)

The radius and slant height of a conical vessel are $21 \,cm$ and $29 \,cm$ respectively. What is its capacity in litres?

The volume of a cuboid with length $25\, cm$ and breadth $15\, cm$ is equal to the volume of a cube with edge $15\, cm$. Find the height of the cuboid (in $cm$).

For a given cylinder,the diameter of the base is $7 \,cm$ and its height is $12 \,cm$. Find the curved surface area of a cylinder (in $cm^2$).

The diameter of a solid hemisphere is $7 \, cm$. Find its curved surface area and total surface area (in $cm^2$).