gwd6-33

由 **bryan** » 2004-12-08 12:36

Enrollment in City College in 1980 was 83⅓ percent of enrollment in 1990. What was the percent increase in the college’s enrollment from 1980 to 1990?

A. 10%
B. 16⅔%
C. 20%
D. 25%
E. 183⅓%

答案是C

我的算法是 (1-83⅓%) / (83⅓%)=38.5%，找不到答案
我哪裡弄錯了？

由 **bugubugu** » 2004-12-08 14:27

我的算法是醬...

83又1/3 250/3
---------- = --------- = 5/6
100 100

1
------ -1 = 1/5 =20%
5/6

你算的方式也會得到此答案...

(1-83⅓%) / (83⅓%)= (1-5/6)/(5/6) = (1/6)/(5/6) = 1/5 =20%

所以....
是你計算錯誤而已啦....