$A$ metal sphere with a radius of $12\, cm$ is melted,and recast into cones with radius $3\, cm$ and height $4\, cm$. Find how many cones are obtained?

$A$ right triangle with sides $6 \, cm, 8 \, cm$ and $10 \, cm$ is revolved about the side $8 \, cm$. Find the volume and curved surface area of the cone so formed. $(\pi = 3.14)$

Metal spheres,each of radius $2 \, cm$,are packed into a rectangular box of internal dimensions $16 \, cm \times 8 \, cm \times 8 \, cm$. When $16$ spheres are packed,the box is filled with preservative liquid. Find the volume of this liquid. Give your answer to the nearest integer. [Use $\pi = 3.14$] (in $cm^3$)

$A$ shopkeeper has one spherical laddoo of radius $5 \, cm$. With the same amount of material,how many laddoos of radius $2.5 \, cm$ can be made?

The total surface area of a cube is $864 \, cm^2$. Then its edge is $\ldots \ldots \ldots \, cm$.

$A$ small village, having a population of $5000$, requires $130\, \text{litres}$ of water per head per day. The village has an overhead cuboidal tank measuring $20\, \text{m} \times 13\, \text{m} \times 10\, \text{m}$. For how many days will the water of this tank last?