请教各位牛人：

         本人在做GWD31套时遇到这样一道题，题号为：GWD-20-14,对下面一道求概率的题有点疑惑，望指点迷津，谢谢

Q14:

Six cards numbered from 1 to 6 are placed in an empty bowl.  First one card is drawn and then put back into the bowl; then a second card is drawn.  If the cards are drawn at random and if the sum of the numbers on the cards is 8, what is the probability that one of the two cards drawn is numbered 5 ?

 A.1/6           B.1/5           C.1/3            D.2/5             E.2/3

Key

如果加一起是8 那么只能是  （2，6）（3，5）（4，4）（5，3）（6，2）中间有5的只有）（3，5）（5，3）

所以概率就是2/5

2+6

6+2

3+5

5+3

4+4

共五种情况。。。

2/5