Answer:
5000 gallons of water will be consumed each month.
Explanation:
One day's discharge at its mouth = 2 trillion gallons = 2×
gallons of water.
This amount of discharge could supply all of country's households for the time = 4 months
So consumption in one month =

If the numbers of households in the country A are 100 million or

So water consumption by each household in one month
=
=

=

= 5000 gallons
5000 gallons of water is consumed by each household in a month.