Question.
A village, having a population of 4000 , requires 150 litres of water per head per day. It has a tank measuring $20 \mathrm{~m} \times 15 \mathrm{~m} \times 6 \mathrm{~m}$. For how many days will the water of this tank last?
Solution:
The given tank is cuboidal in shape having its length (l) as 20 m, breadth (b) as 15 m, and height (h) as 6 m.
Capacity of tank $=1 \times b \times h$
$=(20 \times 15 \times 6) \mathrm{m}^{3}=1800 \mathrm{~m}^{3}=1800000$ litres
Water consumed by the people of the village in 1 day $=(4000 \times 150)$ litres
= 600000 litres
Let water in this tank last for n days.
Water consumed by all people of village in n days = Capacity of tank
$n \times 600000=1800000$
$n=3$
Therefore, the water of this tank will last for 3 days.
The given tank is cuboidal in shape having its length (l) as 20 m, breadth (b) as 15 m, and height (h) as 6 m.
Capacity of tank $=1 \times b \times h$
$=(20 \times 15 \times 6) \mathrm{m}^{3}=1800 \mathrm{~m}^{3}=1800000$ litres
Water consumed by the people of the village in 1 day $=(4000 \times 150)$ litres
= 600000 litres
Let water in this tank last for n days.
Water consumed by all people of village in n days = Capacity of tank
$n \times 600000=1800000$
$n=3$
Therefore, the water of this tank will last for 3 days.