Lateral surface area of a cube $= \ldots \ldots \ldots$

Find the amount of water displaced by a solid spherical ball of diameter $4.2 \, cm$,when it is completely immersed in water. (in $, cm^3$)

Curved surface area of a cone $= \dots$

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 radii of five metal spheres are $1\, cm, 3\, cm, 4\, cm, 5\, cm$ and $8\, cm$ respectively. If they are melted and cast into a single large sphere,find the radius of that sphere. Furthermore,if this large sphere is melted and recast into smaller cylinders,each with a radius of $3\, cm$ and a height of $4\, cm$,how many such cylinders can be formed?

Find the total surface area of a hemisphere of radius $42 \, cm$. (in $cm^2$)