Question

In a community with a population of 45,000, it is estimated that each person needs 12 litres of water each day. The community has a centralized reservoir which is cylindrical with a radius of 7 m and height 20 m, if the reservoir is half filled, how long to the nearest day will the water lost (take pi=22/7)

Answer 1

[AI-generated answer — Bot GPT 3.5]

First, we need to calculate the total capacity of the reservoir.

The formula for the volume of a cylinder is V = πr^2h, where r is the radius and h is the height.

Given that the radius (r) is 7m and the height (h) is 20m, we can calculate the total capacity of the reservoir:

V = π(7)^2(20)
V = π(49)(20)
V ≈ 3079.429 m^3

Since the reservoir is half-filled, the water level is at 0.5 * 3079.429 = 1539.7145 m^3.

Now, we need to calculate how many days it will take for the community to run out of water with the given usage rate.

Each person needs 12 litres of water per day. In total, the community needs 45000 * 12 = 540000 litres of water per day.

Converting litres to cubic meters, we have 540000 / 1000 = 540 m^3 of water needed per day.

The community has 1539.7145 m^3 of water remaining. To calculate how many days it will last, we divide the remaining water by the daily water usage:

1539.7145 / 540 ≈ 2.852 days

Therefore, the water will last approximately 3 days before running out.