company A has 110 employed, company B has 750 employed and company C has 250 employed. Compute the probability that an employee selected at random comes from company A or B.

Size of set A = |A| = 110,

similarly |B|=750, |C|=250
Size of Ω, sample space, S = |A|+|B|+|C|=1110

Random selection from equi-probability sample would be
P(A or B)=P(A)+P(B)=(|A|+|B|)/S

To compute the probability that an employee selected at random comes from company A or B, we need to first determine the total number of employees in companies A and B.

Total employees in company A = 110.
Total employees in company B = 750.

The total number of employees in companies A and B is obtained by summing up the number of employees in each company:

Total employees in A and B = 110 + 750 = 860.

Now, to compute the probability, we divide the total number of employees in A and B by the sum of the total number of employees in all the companies:

Probability = (Total employees in A and B) / (Total employees in all companies)

Total employees in all companies = Total employees in A + Total employees in B + Total employees in C

Total employees in all companies = 110 + 750 + 250 = 1110

Probability = (860) / (1110)

Probability ≈ 0.7748

Therefore, the probability that an employee selected at random comes from company A or B is approximately 0.7748.