Question

A housing society consisting of 5,500 people needs 100 L of water per person per day. The cylindrical supply tank is 7 m high and has a diameter 10 m. For how many days will the water in the tank last for the society?

Answer 1

Total number of people = 5500

Water required per person per day = 100 L

Total requirement of water by 5500 peoples = 100 × 5500 = 550000 L

Height of the cylindrical tank = 7 m

Diameter of the cylindrical tank = 10 m

∴ Radius = 5 m   ...`[∵ ("Diameter")/2 = "Radius"]`

∴ Volume of cylinder = πr²h

= `22/7 xx 5 xx 5 xx 7`

= 22 × 25

= 550 m³

= 550 × 1000  ...[∵ 1 m³ = 1000 L]

= 550000 L   

Hence, for 1 day the water in the tank lost for the society and in one day society needs 550000 L of water.