A) A village having a population of 1500 needs 120 litres of water per head per day.It has a tank measuring 20m*15m*6m full of fresh water.Due to some fault , the tank is not getting the water.For how many days will the water of this tank last? b) If the fault is not removed and there is water in the tank even after 5 days.Will you recommend villagers to drink this stagnent and stale water? Explain

we got the same in our qp in maths exam class 9 cbse


Water used by total population in a day = 1500 * 120
                                                               = 180000 l

Water in the tank = 20*15*6 m3
                            =1800 m3
                            =1800*1000 l
                            =1800000 l
 let number of days be y

y * water used by whole in 1 day = total volume of water
y*180000 = 1800000
y = 1800000 / 180000
y = 10
the water will last for 10 days

It is not advisable to drink stagnant water of the tank after 5 days