A village, having a population of 4000,
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.
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