23.
(A)6
(B)7
(C)8
(D)9
(E)-
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統計: A(5), B(0), C(3), D(9), E(0) #459029
統計: A(5), B(0), C(3), D(9), E(0) #459029
詳解 (共 3 筆)
#986295
有男也有女的機率=1-全為男機率-全為女機率
=1-[C(20,4)/C(35,3)]-[C(15,3)/C(35,3)]
=1-[(20!/4!16!)/(35!/3!32!)]-[(15!/3!12!)/(35!/3!32!)]
=1-(57/187)-(13/187)
=1030/1309
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