Answer:
9,000,000,000 gallons of water.
Step-by-step explanation:
We have been given that a website recommends that you should have 3 gallons of water for every inch of goldfish in your tank. We are asked to find the gallons of water needed for one billion goldfish that are each 3 inches.
First of all, we will find gallons of water needed for each fish.
Now, we will multiply number of gallons of water required for 1 fish by 1 billion to find required gallons of water.
Therefore, you need 9,000,000,000 gallons of water for 1 billion fish.