Question

In a railway reservation office, two clerks are engaged in checking reservation forms. Onan average, the first clerk (A1) checks 55 per cent of the forms, while the second (A2)checks the remaining. While A1 has an error rate of 0.03 that of A2 is 0.02. A reservationform is selected at random from the total number of forms checked during a day and isdiscovered to have an error. Find the probabilities that it was checked by A1, and A2,respectively.3.

Answer 1

probability that it is checked by a1=[0.03*55/100]/[0.03*55/100+0.02*45/100]
                                                 =1.65/2.55=11/17
probability that it is checked by a2=[0.02*45/100]/[0.03*55/100+0.02*45/100]
                                                  =0.9/2.55=6/17