The water will last for 3 days
<em><u>Solution:</u></em>
Given that, village having a population of 4000, requires 150 litres of water per head per day
<em><u>Let us first find the volume of tank</u></em>
The tank measuring 20m x 15m x 6m
Length = 20 m
Breadth = 15 m
Height = 6 m
Thus volume of tank is 1800 cubic meter
From given,
Water required per person per day = 150 liters
<em><u>Therefore, water required for 4000 people per day is:</u></em>
Convert to meters
<em><u>How many days will the water of this tank last?</u></em>
Thus the water will last for 3 days
