袋中有5个球(3新2旧),每次取1个,无放回的抽取2次,则第2次取到新球的概率为()
①
<imgwidth="14"height="41"v:shapes="_x0000_i1215"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image315.png">
②
<imgwidth="16"height="41"v:shapes="_x0000_i1216"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image317.png">
③
<imgwidth="16"height="41"v:shapes="_x0000_i1217"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image319.png">
④
<imgwidth="21"height="41"v:shapes="_x0000_i1218"src="http://wljy.whut.edu.cn/uploadfiles/word/xxdsb06.files/image321.png">