# The City Has A Revoir Of water for public use that currently has 125,000,000 gallons of water every week. How much water it will be left in the reservoir after a year?

Jul 25, 2018

What is the initial water volume in the reservoir?

#### Explanation:

Let me accept the current volume of the reservoir is $10 , 000 , 000 , 000$ gallons (or $2 , 641 , 729$ cubic meters).

If there is no evaporation from the reservoir and there is no loss (e.g. infiltration into the ground), the final water will be:

$10 , 000 , 000 , 000 - \left(52 \times 125 , 000 , 000\right)$ gallons

Note that there are 52 weeks in a year

$= 3 , 500 , 000 , 000$ gallons water will be available after a year.

If you say the initial water volume stored in this reservoir is V, the final volume after a year will be

$V - \left(52 \times 125 , 000 , 000\right) = V - 6 , 500 , 000 , 000$ gallons