✔ 最佳答案
請教臺彩539是39個號碼中開出5個號碼,那要猜中兩個及三個號碼同時
開出的機率各是多少?
Sol
C(39,5)=39!/(5!34!)=575757
C(34,5)=34!/(5!29!)=278256
C(5,2)=5!/(2!3!)=10
C(34,4)=34!/(4!30!)=46376
C(34,3)=34!/(3!31!)=34*33*32/6=5984
C(5,3)=5!/(3!2!)=10
C(34,2)=34!/(2!32!)=561
C(5,4)=5!/(4!1!)=5
C(34,1)=34!/(1!33!)=34
P(猜中0個號碼)
=C(5,0)*C(34,5)/C(39,5)
=1*278256/575757
=0.4832872
P(猜中1個號碼)
=C(5,1)*C(34,4)/C(39,5)
=5*46376/575757
=0.4027393
P(猜中2個號碼)
=C(5,2)*C(34,3)/C(39,5)
=10*(34*33*32/6)*120/(39*38*37*36*35)
=59840/575757
=0.1039327
P(猜中3個號碼)
=C(5,3)*C(34,2)/C(39,5)
=10*561/575757
=0.0097436
P(猜中4個號碼)
=C(5,4)*C(34,1)/C(39,5)
=5*34/575757
=0.0002952
P(猜中5個號碼)
=C(5,5)*C(34,0)/C(39,5)
=1/575757
=0.0000017