Final answer:
To calculate the time it takes to fill the pool, subtract the initial water volume from the total pool capacity and divide by the rate of water flow. It takes Stacy 158 minutes to fill the pool.
Step-by-step explanation:
The question asks how long it will take Stacy to fill an 800-gallon pool if she is adding water at a rate of 5 gallons per minute, starting with an initial volume of 10 gallons. To solve this, we first need to subtract the initial volume from the total volume needed. So, 800 gallons minus the initial 10 gallons leaves us with 790 gallons to fill. Next, we divide the remaining volume by the rate of flow:
790 gallons ÷ 5 gallons/minute = 158 minutes.
Therefore, it would take Stacy 158 minutes to fill the pool.