求正解Prep01的PS 17题

julia7718

In a certain board game, a stack of 48 cards, 8 of which represent shares of stock, are shuffled and then placed face down.  If the first 2 cards selected do not represent shares of stock, what is the probability that the third card selected will represent a share of stock?

(A)  1/8

(B)  1/6

(C)  1/5

(D)  3/23

(E)  4/23

答案是C8,1/C46,1吗？即
E？

julia7718

牛人快来帮俺看看，先谢谢了，文科生数学天敌牙

滨崎步祝

是E没错啊

Laurielin

就是 8/ (48-2)

julia7718

滨崎步祝 发表于 2013-9-3 19:38
是E没错啊

感谢哦，主要是对数学太没自信了

julia7718

Laurielin 发表于 2013-9-3 19:53
就是 8/ (48-2)

感谢回复，这下心里更有底了