You can either use a ratio, or just multiply. But, a ratio does lead to multiplying in this situation. 1 Container : 55 balls; This is the ratio for one container. 9 Containers : Y balls; This is the ratio we're trying to solve, y is the number we're trying to solve. Since you're multiplying the container by 9, you need to multiply the balls by 9. 55×9 495. So D. 495 balls are in 9 containers.