Question:
A village having a population of 4000 requires 150 liters 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 that,
Length of the cuboidal tank (l) = 20 m
Breadth of the cuboidal tank (b) = 15 m
Height of the cuboidal tank (h) = 6 m
Capacity of the tank = l * b * h = 20 * 15 * 6
$=1800 \mathrm{~m}^{3}$
= 1800000 litres
Water consumed by the people of village in one day = 4000 *150 litres
= 600000 litres
Let water of this tank last for 'n' days
Therefore, water consumed by all people of village in n days = Capacity of the tank
= n*600000 = 1800000
= n = 1800000/600000 = 3
Thus, the water will last for 3 days in the tank.