Areportercoveringanaturalizationceremonywantstorandomlyselectnewcitizenstointerview.Outofthe200newAmericancitizens,7ofthemarefromEcuador,and10ofthemarefromKenya.WhatistheprobabilitythatthereporterwillrandomlyselectapersonfromEcuadorfirstandthenapersonfromKenyatointerview?
A.7/4000
B.7/3980
C.7/400
D.7/398[阅读全文]
博文
(2010-09-02 16:52:45)
