Job Recruitment Website - Job seeking and recruitment - A graduate attends a job fair and submits his resume to company A, company B and company C, assuming the probability that the graduate is interviewed by company A.. ...

A graduate attends a job fair and submits his resume to company A, company B and company C, assuming the probability that the graduate is interviewed by company A.. ...

If X is the number of companies interviewed by the graduate, the possible values of X are 0, 1, 2,3, ∫P(X = 0)= 0.

1 12

,∴

( 1? p)2 =

1 12

,∴p=

，p(x = 1)= 0

4 12

p(X = 2)= 1

5 12

，p(x=3)= 1-

1 12

4 12

5 12

2 12

,∴EX= 1×

4 12

+2×

5 12

+3×

2 12

So the answer is: 53.