这个答案正确.不过,我的算法不同:

Blue_Diamond 2010-06-15 00:05:22 ( reads)

P=(C(19,6)-7*(C(8,5)+C(7,5)+C(6,5)+C(5,5)))/10^7
=(27132-7*(56+21+6+1))/10000000
= 0.0026544