The ratio of red circles to blue circles is 1:3 How many more red circles would need to be added to make the ratio of red to blue 3:1?

8 more red circles will be needed

The answer is 8 because since there are 3 blue circles, you would need to have 3 times as many red circles as there are blue. Therefore, you would need to balance the ratio from 3:1 to 9:3. These are equal, just simplified. So 8 would be your answer.