# 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?

**Solution:**

Given : 150 litres of water requires per head per day in a village of 4000 population. The dimensions of the tank are 20 m × 15 m × 6 m

We have to find the number of days, the water of this tank will last.

Since the tank is cuboidal in shape, the volume of water in the tank will be equal to the volume of the cuboid.

The volume of cuboid of length l, breadth b, and height h, is l × b × h

First, we will find the requirement of water per day for a total of 4000 population in cubic metres and the volume of the water in the tank.

The number of days for which the water of the tank will last can be obtained by dividing the volume of the water in the tank by the requirement of water per day for the total population.

Requirement of water per head per day is 150 litres.

Requirement of water per day for 4000 population = 4000 × 150L

= 600000L

= 600000/1000 m^{3} (∵ 1000L = 1 m^{3})

= 600 m³

Length of the tank, l = 20 m, Breadth of the tank, b = 15 m, and Height of the tank, h = 6 m

The volume of the water in the tank = l × b × h

= 20m × 15m × 6m

= 1800 m^{3}

Number of days for which the water of the tank will last = 1800m^{3}/600m^{3} = 3 days

**Video Solution:**

## 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?

### Class 9 Maths NCERT Solutions - Chapter 13 Exercise 13.5 Question 6:

**Summary:**

A village, having a population of 4000, requires 150 litres of water per head per day. If the tank measures 20 m × 15 m × 6 m, we have found that the water in the tank will last for 3 days.