问道数学题~望解释~~谢啦~~~

LIANGSHAN

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 in next $108 million in sales. By approximately what percent did the ratio of royalties to sales decrease from the first $2o million in sales to the next $108 million in sales？

many thanks~!

fangzep

44.67%

用两次的比例相比较

我觉得应该是这样

fengyingx

设the ratio of royalties on the first $20 million in sales 为x, the ratio of royalties on the next $108 million in sales 为y

则 20*x=3; 108*y=9 则本题所求为x-y; 结果等于15分之1, 我是新人, 不知道GMAT的小数点是不是和中文数学一样, 要保留两位小数...