$3$ 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.

$A$ brick measures $20 \, cm$ by $10 \, cm$ by $7.5 \, cm$. How many bricks will be required to construct a wall $25 \, m$ long,$2 \, m$ high,and $0.75 \, m$ thick?

How many coins,$2 \, mm$ thick and $1.5 \, cm$ in diameter,should be melted in order to form a right circular cylinder with base diameter $6 \, cm$ and height $8 \, cm$?

$5$ persons will live in a tent. If each person requires $16\, m^2$ of floor area and $100\, m^3$ space for air,then the height of the cone of smallest size to accommodate these persons would be? (in $m$)

If $64$ buckets of water are removed from a cubical-shaped water tank completely filled with water, $1/3$ of the tank remains filled with water. The length of each side of the tank is $1.2\, m$. Assuming that all buckets are of the same measure, then the volume (in $litres$) of water contained by each bucket is:

$A$ cylindrical can with a horizontal base and an internal radius of $3.5 \, cm$ contains sufficient water so that when a solid sphere is placed inside,the water just covers the sphere. The sphere fits exactly into the can. The depth of the water in the can before the sphere was added is: