$3$ equal cubes are placed adjacently in a row. Find the ratio of the total surface area of the new cuboid to the sum of the surface areas of the three cubes.

$A$ $3.3\, m$ high room is half as long again as it is wide and its volume is $123 \frac{3}{4}\, m^3$. Find its length and breadth.

$2$ cans have the same height equal to $21\, cm$. One can is cylindrical,the diameter of whose base is $10\, cm$. The other can has a square base of side $10\, cm$. What is the difference between their capacities? (in $cm^3$)

$A$ $12\,m$ deep well with internal diameter $3.5\,m$ is dug. The earth taken out from it is spread evenly to form a platform of dimensions $10.5\,m \times 8.8\,m$. Determine the height of the platform in meters. (in $.25$)

The height and base radius of a cone are each increased by $100 \%$. The volume of the cone now becomes

$A$ rectangular water tank is $80 \, m \times 40 \, m$. Water flows into it through a pipe with an opening area of $40 \, cm^2$ at a speed of $10 \, km/h$. By how much will the water level in the tank rise in half an hour (in $cm$)?