标题: 求此道prep题的详解！ [打印本页] 作者: 500023 时间: 2010-3-4 09:00 标题: 求此道prep题的详解！ each of the 25balls in a certain box is either red ,blue or white and has a number from 1 to10 painted on it. if one ball is slected at ramdom from box, what is probablity that the ball selected will either be white or have a even number painted on it?
(1 the probablity that the ball will both be white and have a even number painted on it is 0. 2) the probablity that the ball will be white minus the probablity that the ball will have a even number painted on it is 0.2.作者: 500023 时间: 2010-3-4 09:01
不好意思，传的是图片，所以看不清楚，麻烦各位NN，把图片拖出来单独成一页面，就可以看清了！作者: kingapple25 时间: 2010-3-4 10:48
拖出来也打不开，lz最好重新上传一下~