某公司招聘员工,指定三门考试课程,有两种考试方案.
1个回答

记该应聘者对三门指定课程考试及格的事件分别为A,B,C,

则P(A)=0.5,P(B)=0.6,P(C)=0.9.--------------(2分)

(Ⅰ) 应聘者用方案一考试通过的概率

p 1=P(A•B•

.

C )+P(

.

A •B•C)+P(A•

.

B •C)+P(A•B•C)

=0.5×0.6×0.1+0.5×0.6×0.9+0.5×0.4×0.9+0.5×0.6×0.9

=0.03+0.27+0.18+0.27

=0.75.--------------(7分)

(Ⅱ) 应聘者用方案二考试通过的概率

p 2=

1

3 P(A•B)+

1

3 P(B•C)+

1

3 P(A•C)

=

1

3 ×(0.5×0.6+0.6×0.9+0.5×0.9)

=

1

3 ×1.29

=0.43--------------(12分)