pls help me one math question

hopelight

X, Y, and Z each try independently to solve a problem. if their individual probabilities for success are 1/4,1/2, and 5/8, respectively, what is the probability that X and Y, but not Z, will solve the problem?
答案为3/64, 我根本不知道怎么算出来的. 最怕摡率及排列组合的题,希望得到帮助.
[em08]

investdaily

1/4 x 1/2 x [1-(5/8)]
= (1/8) x (3/8)
= 3/64

Is it correct?

David0822

agree

[此贴子已经被作者于2002-11-14 8:51:56编辑过]

[此贴子已经被作者于2002-11-14 8:53:35编辑过]

hopelight

Thanks.