Q14: A pharmaceutical company received $3 million in royalties on the first $20 million in sales of the generic equivalent of one of its products and then $9 million in royalties on the next $108 million in sales. By Approximately what percent did the ratio of royalties to sales decrease from the first $20 million in sales to the next $108 million in sales?
A. 8%
B. 15%
C. 45%
D. 52%
E. 56%
ans: C
奇怪?? 看來很簡單, 但是我找不到答案???