[em:62][em:54]求解GWD4-17

leweiyang

17.Last year the price per share of Stock X increased by k percent and the earnings per share of Stock X increased by m percent, where k is greater than m.  By what percent did the ratio of price per share to earnings per share increase, in terms of k and m?

A k/m%
B (k – m) %
C [100(k – m)] / (100 + k) %
D [100(k – m)] / (100 + m) %
E [100(k – m)] / (100 + k + m) %

特别看不懂最后的问题，什么意思？哪位nn能帮忙解解？答案选D

sdcar2010

Category  2009    2010
price            p       (100+k)% * p
earning        e       (100+m)% * e
p/e              p/e    [(100+k)/(100+m)] * [p/e]

percentage increase in p/e ratio = 100% * {[(100+k)/(100+m)] * [p/e] - [p/e]} / [p/e]
                                               = 100%* [(100+k)/(100+m) - 1]
                                               = 100% * [(k-m)/(100+m)]

leweiyang

噢我明白了，是求增长后的ratio跟之前ratio增长的比率！
谢谢sdcar2010~~:）