$A$ storage tank is in the form of a cube. When it is full of water,the volume of water is $15.625 \, m^3$. If the present depth of water is $1.3 \, m$,find the volume of water already used from the tank (in $m^3$).

Find the surface area and volume of a sphere of diameter $28 \, cm$.

State whether the following statement is true or false:
The radius of a cone can be $3 \, cm$,slant height $4 \, cm$,and height $5 \, cm$.

$A$ 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?

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

$A$ 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. $(\pi = 3.14)$