Three goldfish out of 12 goldfish in the aquarium ate there food

how do i get the ratio

The original ratio would be 3 goldfish who ate their food: 12 goldfish total. To simplify, this would be 1:4 goldfish. Unless the question was asking how many goldfish ate their food versus those who did not, I believe that this would be the answer.

The right answer should be 6 but your not very specific