她为什么打了乒乓球?

湖南省长沙市 胡娟供稿

Xiao Xue asked Ming Ming to play table tennis with her.小雪一直吵着要明明陪她一起打乒乓球。

Ming Ming was troubled and so he had a good idea.明明被吵得实在受不了，于是想出一个妙计。

“Xiao Xue!There are two table tennis balls in the bag.One is yellow and the other is white.Now,you fetch the ball.If you get the yellow one,I will play with you.But if you get the white one,I will quit,and remember you must not trouble me!”“小雪，这个袋子里放了两个乒乓球，一个是黄色的，另一个是白色的。现在，你伸出手去拿乒乓球。如果你拿到黄色的，我就陪你玩，但如果拿到的是白色的，你就要放弃，而且不能再吵我了！”

Xiao Xue put two white balls in the bag when Ming Ming was off guard.So,Xiao Xue would get the white one.But Xiao Xue played table tennis with Ming Ming.But do you know why?小雪的眼睛顿时亮起来，但此时却瞥见转身的明明放了两个白色乒乓球进去。那么，不论她拿到哪一个都会是白色的。小雪最后还是打了乒乓球。请问你知道为什么吗？