The capacity of a closed cylindrical vessel of height $1 \, m$ is $15.4$ litres. How many square metres of metal sheet would be needed to make it (in $, m^{2}$)?

$A$ dome of a building is in the form of a hemisphere. From inside,it was white-washed at the cost of $Rs. 4989.60$. If the cost of white-washing is $Rs. 20$ per square metre,find the volume of the air inside the dome. (in $, m^3$)

It costs $Rs. 2200$ to paint the inner curved surface of a cylindrical vessel $10\, m$ deep. If the cost of painting is at the rate of $Rs. 20$ per $m^2$,find the capacity of the vessel. (in $, kl$)

The edges of three of the four cubes are $1\, cm, 9\, cm$ and $10\, cm$ respectively. If the total volume of two cubes with $9\, cm$ edge and $10\, cm$ edge is equal to the volume of the remaining two cubes,find the edge of the fourth cube in $cm$.

In a cylinder,if the radius is halved and the height is doubled,the volume will be

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 $\pi = 3.14$)