Answer: Aye aye, cap'in
Explanation:
So we start off with our base value, 1/3 gallons.
We are trying to find how many gallons we have eaten, so we do 1/3*1/3, since we need to find what is 1/3rd of that gallon.
For reference, if you wanted to find how much is left over, we multiply by 2/3 since 1-1/3 = 2/3, so there are 2/3 of the 1/3rd gallons left. Not important for solving this problem, but it might help you understand why we decided to multiply by 1/3.
1/3 * 1/3 = 1/9
Our answer is 1/9.