Question

A website recommends that you should have 4 gallons of water for every inch of

goldfish length in your tank.
Question 1
If you have one billion goldfish that are each 3 inches long, how many gallons of water
would you need?

Answer 1

The fish needed 9 billion gallon of water
What is Unitary method?
The unitary method is a technique for solving a problem by first finding the value of a single unit, and then finding the necessary value by multiplying the single unit value.
Given:
goldfish that are each 3 inches long.
So, Gallons of water for each fish = 3*3 = 9
as,
1 billion= 1,000,000,000
Now, Gallons of water for 1 billion fish = 9*
1,000,000,000
Gallons of water for 1 billion fish =
9,000,000,000