53.1%
所有跟帖:
• P(30,6)*C(7,2)/30^7=0.410511111,I use 5 people carelessly. -jinjing- ♀ (38 bytes) () 04/23/2010 postreply 13:22:21
• agree~~~ -cheerleaders- ♀ (578 bytes) () 04/23/2010 postreply 17:13:05
• P(30,6)*C(7,2)/30^7=0.410511111,I use 5 people carelessly. -jinjing- ♀ (38 bytes) () 04/23/2010 postreply 13:22:21
• agree~~~ -cheerleaders- ♀ (578 bytes) () 04/23/2010 postreply 17:13:05