Final answer:
After 3 minutes, there will be 15 gallons of water in the fish tank. It will take 8 minutes to fill the tank with 40 gallons of water.
Step-by-step explanation:
To answer the first question, we need to know the rate at which water flows into the fish tank. Let's say the tank is being filled at a rate of 5 gallons per minute. After 3 minutes, the tank will have 3 minutes multiplied by 5 gallons per minute, which is 15 gallons of water. For the second question, we need to find the time it takes to fill the tank with a certain amount of water. If the tank has a capacity of 40 gallons and is being filled at a rate of 5 gallons per minute, it will take 40 gallons divided by 5 gallons per minute, which is 8 minutes to fill the tank.