[求助]亲爱的们，帮忙看道数学题~~

gillcx

18. Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solution Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new solution is liquid X?
(A) 30%
(B) 33.33%
(C)37.5 %
(D) 40%
(E) 50%

[此贴子已经被作者于2008-12-23 14:13:01编辑过]

hopefaith001

这个数列你可以推算 出来：-3，-1， 1， 3，5，7，9，11.  answer, B

gillcx

谢谢，这题解决了咯，麻烦看下上面一道，怎么想也想不明白。。。

onlyourain

以下是引用gillcx在2008-12-23 11:46:00的发言：

18. Solution Y is 30 percent liquid X and 70 percent water. If 2 kilograms of water evaporate from 8 kilograms of solution Y and 2 kilograms of solution Y are added to the remaining 6 kilograms of liquid, what percent of this new solution is liquid X?
(A) 30%
(B) 33.33%
(C)37.5 %
(D) 40%
(E) 50%

   

      8 kilograms solution 包括 2.4 kilograms of x and 5.6 kilograms of water.

      thus ,  water-2=3.6

      then 2 kilograms solution added into the solution includes 0.6 kilograms of x &1.4 kilograms  of water

      so, new solution includes 3 kilograms of x & 5 kilograms of water

      results=3/8=37.5%

      lz应该是把后来加的solution看错了吧，所以才算不出结果。

[此贴子已经被作者于2008-12-23 15:27:37编辑过]

gillcx

嗯嗯，谢谢~~