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

Explanation

Given, l = 20, b = 15 m and h = 6 m
`therefore` Capacity of the tank = volume of the tank = lbh
`=(20xx15xx6)m^(3)=1800 m^(3)`
`because` Water required per person per day = 150 L
Water required for 4000 persons per day `=(4000xx150)L`
`=((4000xx150)/(1000))m^(3) " " (because 1L=(1)/(1000)m)`
`=600 m^(3)`
`therefore` Number of days the water will last `= ("Capacity of tank")/("Total water required per day")`
`= (1800)/(600)=30`
Hence, the water will last for 30 days.