A village having a population of 4000 requires 150 litres of water per head per day. It has a tank measuring 20 m×15 m×6 m. For how many days will the water of this tank last?

A rectangular tank is 80 m long and 25 m broad. Water flows into it through a pipe whose cross-section is 25 cm², at the rate of 16 km per hour. How much the level of the water rise in the tank in 45 minutes.

Water in a rectangular reservoir having base 80 m by 60 m is 6.5 m deep. In what time can the water be emptied by a pipe of which the cross-section is a square of side 20 cm, if the water runs through the pipe at the rate of 15 km/hr.

A child playing with building blocks, which are of the shape of the cubes, has built a structure as shown in Fig. 18.12. If the edge of each cube is 3 cm, find the volume of the structure built by the child.

A godown measures 40 m×25 m×10 m. Find the maximum number of wooden crates each measuring 1.5 m×1.25 m×0.5 m that can be stored in the godown.