Figure shows the end face of a triangular girder which is $5 \mathrm{m}$ long. Find the volume of metal used in casting it. (Units in cm).

The figure shows the end-face of a garage which is $20 \mathrm{m}$ long. Find the area of the end-face.

The figure shows the end-face of a garage which is $20 \mathrm{m}$ long. Find the volume of the air-space of the garage in ${\mathrm{m}}^3$.

The figure shows the end-face of a garage which is $20 \mathrm{m}$ long. If $40 {\mathrm{m}}^3$ of air is required per worker, how many workers can be employed in his garage?

The areas of three consecutive faces of a cuboid are $12 {\mathrm{cm}}^2, 20 {\mathrm{cm}}^2$ and $15 \mathrm{cm}$, then the volume (in ${\mathrm{cm}}^3$) of the cuboid is

A hall is $15 \mathrm{m}$ long and $12 \mathrm{m}$ broad. If the sum of the areas of the floor and the ceiling is equal to the sum of the areas of the four walls, the volume of the hall in $\mathrm{cu} \mathrm{m}$ is

Water flows into a tank which is $200 \mathrm{m}$ long and $150 \mathrm{m}$ wide through a pipe of cross section $0.3\times 0.2 \mathrm{m}$ at $20 \mathrm{km}/\mathrm{hr}$. Then the time (in $\mathrm{hours}$) for the water level in the tank to reach $8 \mathrm{m}$ is

A rectangular sheet of metal is $40 \mathrm{cm}$ by $15 \mathrm{cm}$. Equal squares of side $4 \mathrm{cm}$ are cut off at the corners and the remainder is folded up to form an open rectangular box. The volume of the box is