Statistics ms-08

In a railway reservation office, two clerks are engaged in checking reservation forms. On
an 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 reservation
form is selected at random from the total number of forms checked during a day and is
discovered to have an error. Find the probabilities that it was checked by A1, and A2,
respectively.