Final answer:
The ratio of Amy's score to Bill's score to Cara's score is 10:1:5.
Step-by-step explanation:
The question involves the mathematical concept of ratios and proportions. If we let Amy's score be represented by 'A' and Bill's score by 'B', then according to the question Amy's score is ten times Bill's score, so we can write A = 10B. Furthermore, Cara's score is half of Amy's score, so if we denote Cara's score as 'C', we have C = A/2 or C = 5B (since A is 10B).
Now that we have these relations, we can express the ratio of Amy's score to Bill's score to Cara's score. A:B:C = 10B:B:5B. To simplify this ratio, we divide each part by B, since it is the common factor. This gives us the ratio of 10:1:5.