$3$ 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.

The ratio of the curved surface area and volume of a cylinder is $1:7$. The ratio of the total surface area and volume is $187:770$. What is the ratio of its base radius to its height?

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

Find the weight of a hollow cylindrical lead pipe $28\, cm$ long and $0.5\, cm$ thick. Its internal diameter is $8\, cm$. (in $kg$) (Weight of $1\, cm^3$ of lead is $11.4\, g$,$\pi = \frac{22}{7}$)

$A$ right circular cylinder has a height of $18 \, cm$ and a radius of $7 \, cm$. The cylinder is cut into three equal parts by $2$ cuts parallel to the base. What is the percentage increase in the total surface area (in $\%$)?

$A$ solid cone of height $36 \, cm$ and radius of base $9 \, cm$ is melted to form a solid cylinder of radius $9 \, cm$ and height $9 \, cm$. What percent of material is wasted in this process (in $\%$)?