pool has 45000 gallons. It loses 780 gallons per hour, so the amount at any given time:
45000 - 780h, where h is the number of hours.
The chemical could be added once the amount of gallons in the pool hits 15000. So the equation to solve:
45000 - 780h = 15000
solve:
30000 = 780h
38.46 = h
It will take about 38.46 hours before chemical could be added. It will not take longer than 2 days because 2 days is 48 hours, and we only need about 38 hours.
