GWD31套1-8，请赐教，不知哪里没有想到

没有搜到讨论，只好求助各位了

Q8:

In 1997 there were 300 female employees at Company C.  If the number of female employees at Company C increased by 60 percent from 1977 to 1987, by what percent did the number of female employees at Company C increase from 1987 to 1997?

(1)   From 1977 to 1997 the number of female employees increased by 200 percent at Company C.

(2)     In 1977 there were 100 female employees at Company C.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案是E，我的答案完全不沾边，请赐教

1）假设1977是“1”（一个单位的意思）

那1987就是1（1+60%）=1.6

有（1）得1997是1*（1+200%)=3

so from 1987-1997:  (3-1.6)/1.6

2)1977——100

1987——100*（1+60%）

1998——300

(300-160)/160

回楼上，我就是这么算的，但是答案为什么是E啊！！！！

请再赐教