So you have 318/2580 (since the top is the amount of money they use for food and the bottom is the total). You will want to divide it into 2 so 318/2 and 2580/2. Then you will get 159/1290. The divide 159/1290 with 3. So you will get 52/430. It may seem that you will need to divide 430 with 52 now. Once you get that, you will get the decimal 0.123255814. (I used a calculator). Then Move the decimal twice to the right to make that whole percentage. You will get 12 as you whole number (Ignoring the fact you have 3255814 as your remaining.). So the answer for that is….
12%!!