一道数学概率问题英文题目哦
(a)Inthenationallottery,youidentify6ballsfromasetof49balls.Then6ballsareselectedatrandomfromthe49ballsandyougetaprizeifatleast3ofthesematchtheballsyouidentified.(Ignoringthebonusballfornow)
---Whatistheprobabilitythatyougetaprizeofsomesort?
(b)actuallyitismorecomplicated;afterthe5ballsareselectedatrandom,asixth“bonus”ballisselectedatrandomandyougetaspecialkindofprizeif,ofthesixballsyouidentified,5wereintheselectedgroupofsixandthesixthisthebonusball(aswellasalltheprizesformatching3ormoreofthefirstsixballs)
---Whatistheprobabilityyougetaspecialkindofprizejustdescribed?
---Keepingthisinmind,whatistheprobabilitythatyougetaprizeofsomesort?