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?

Given: Length, l = 20 m, Breadth, b = 15 m and Height, h = 6 m

also, the total population of a village is 4000

1 person consumes 150 liters of water in a day

So total population consumes, 4000×150 = 600000 liters

We know that formula to find the volume of cuboid = l × b × h 

Using the given data, we have

C = 20 × 15 × 6 = 1800 m³

 C = 1800000 liters

Let the water in this tank last for 'a' days.

Water consumed by all people in 'a' days = Capacity of tank

600000 × a =1800000

a = 3

Therefore, the water in this tank will last for 3 days.