$A$ 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?

$A$ cylindrical tank of diameter $35 \, cm$ is full of water. If $11$ litres of water is drawn off,the water level in the tank will drop by (in $cm$):

$A$ solid sphere and a solid hemisphere have the same total surface area. The ratio of their volumes is

The radius of the base of a hollow cone is $8\, cm$ and its height is $15\, cm$. $A$ sphere of the largest possible radius is placed inside the cone. What is the ratio of the radius of the base of the cone to the radius of the sphere?

The radius of a cylinder is $10\, cm$ and its height is $4\, cm$. The value of $x$ (in $cm$) that may be added either to the radius or to the height to get the same increase in the volume of the cylinder is:

The cross section of a canal is in the shape of an isosceles trapezium which is $4 \ m$ wide at the bottom and $5 \ m$ wide at the top. If the depth of the canal is $2 \ m$ and it is $120 \ m$ long,what is the maximum capacity of this canal? (in $m^3$)